Pregnant ferrets will require extra protein (not fat) during gestation. Lactating (nursing) ferrets will require extra caloric intake. Abandoned or orphaned kits may be hand raised with either puppy or kitten milk replacer with cream added to raise the fat content. Ill, anorexic ferrets can develop hepatic lipidosis and hypoglycemia. There are good dietary supplements commercially available for assist-feeding anorexic ferrets. Ferrets with insulinomas, a common problem, should be encouraged to eat every few hours.

Whole prey diets (chicks, mice, and/or rats) are fine for ferrets and are popular in certain parts of the world although not so much in North America. Cat food is often fed to ferrets, but ordinary grocery store cat food is a poor choice for them. Premium dry cat foods or balanced commercial ferret diets are better choices. The ideal ferret diet is high in protein (30-35%) and fat (15-30%), and low in fiber. The protein source should be meat-based, rather than grains. Grain-based diets have been associated with urolithiasis in ferrets. Ferrets fed dog food will not do well. Meat or poultry or their by-products should top the ingredient list of any suitable ferret food. A diet in which the first main ingredient is corn is not a suitable diet for ferrets. The feeding of table scraps should be kept to a minimum. There are several brands of supplemental nutritional products for ferrets that are commercially available. These products are unnecessary in most ferrets. Older ferrets may require less protein than when they were younger.

Fruits and vegetables have little nutritional value for ferrets. An adult ferret needs approximately 43 grams of dry food per kilogram of body weight, and 200-300 calories/kilogram per day. Calcium: phosphorus ratios in ferret diets should be minimally 1:1. Dilated cardiomyopathy (DCM) occurs in ferrets, and although it has not been associated with taurine deficiency, taurine is generally added to ferret diets as is the case with cat food. Commercial ferret diets have vitamins and minerals added in adequate amounts. Water should be made available at all times; most ferrets will prefer a bowl to a sipper bottle. They also like to play with their water. Ferrets tend to not be fond of changes in their diet after they are used to a certain kind. Ferrets imprint by smell on the food they like at a very young age. Most ferrets will be content to eat one brand of commercial diet that they enjoy for their entire lives.

Treats should not consist of more than 10 percent of the daily diet. They love raisins; however, while there is no formal study on ferrets and raisins, there are anecdotal reports of raisin toxicosis in ferrets, so raisins are best avoided. Egg can be a good supplement, as can small amounts of liver or hamburger.

The word neuter refers to the removal of the reproductive organs of either a male or a female of a species, although people frequently refer to the surgery in a female as a spay. The scientific terminology for neutering in the male is castration and in the female is ovariohysterectomy. Let’s take a look at the issue of neutering and whether or not it is appropriate for your pet rabbit.

Reasons for Neutering Rabbits 

Prevention of Pregnancy

This is the most common reason that rabbits are neutered, particularly if there are both male and female rabbits living together in a household. There are certainly enough rabbits in the world and too many are neglected or abandoned. One should not consider breeding these pets just for fun or education. Be a responsible pet owner and do not breed your pet unless you are well educated on the topic and are prepared to take on all the responsibilities such activity entails.

Prevention of Uterine Cancer

This is the most compelling medical reason to neuter female rabbits. In some rabbit populations the rate of uterine adenocarcinoma (a malignant uterine cancer) can approach 80% of the females. It is believed that the incidence may be related to the rabbit’s genetic makeup. Since we usually don’t know the genetic background of most of our rabbits, it is best to have the surgery done as a preventative for this cancer. Uterine adenocarcinoma can spread rapidly to other organs of the body such as the liver, lungs and even the skin and it is not treatable once it metastasizes outside of the uterus. We see many cases of this disease each year and sadly these rabbits could have avoided this problem. Rabbits under two years of age rarely develop this disease so it is best to get your female spayed before this age.

Prevention of other Uterine Disease

Although cancer is the most common disease of the rabbit uterus, we see many cases a year of other uterine disease such as pyometra (infected uterus full of pus), uterine aneurism (uterus full of blood) and endometritis (inflamed uterine lining). Like uterine cancer, these conditions are all more common in female rabbits over two years of age.

Prevention of False Pregnancies

Female rabbits can go into a hormonal state triggered by their ovaries where the body acts as if it is pregnant but there is in fact no pregnancy. Although this is not medically harmful, it can be stressful for the rabbit who goes through all the activities of being pregnant including nest building, milk production and aggressive protection of her territory. This aggression can be taken out on the caretakers and cage mates and can make the pet difficult to handle during this period. Some rabbits experiencing false pregnancy will develop a decreased appetite and have gastrointestinal disturbances as well.

Prevention of Mammary Gland (Breast) Disease

Mammary gland cancer is not common in female rabbits, but when it occurs it can spread rapidly and be difficult to treat. It is preventable if the pet is neutered before two years of age. It is interesting to note that the most common type of mammary cancer is a malignant form called mammary carcinoma and it is almost always associated with uterine cancer. The other common mammary gland disease is mammary dysplasia or cystic mammary glands. This is a benign condition, where the mammary glands fill with a cystic material. It can be uncomfortable to the pet. Neutering a female rabbit before two years of age will prevent both of these diseases.

Prevention of Aggressive Behavior

Both male and female rabbits can display aggressive behavior when they are sexually mature. Many rabbits are sweet and easy to handle as little babies, but when the teenage years hit at around six to twelve months of age…watch out! They can become little Frankensteins almost overnight! They don’t want to be touched or picked up and they act like they want to destroy everything in sight. This is their way of learning to protect themselves, their territory and potential future families and to establish their social position in the big wide rabbit world. However, they can often take out their aggression on you or their cage mates. There may be more biting, striking, lunging and chasing. It is best to neuter just before or shortly after sexual maturity to keep this behavior to a minimum.

Prevention of Urine Spraying

Both male and female rabbits can spray urine on vertical surfaces to mark their territory. Intact mature males do this at least 10 times more frequently than females. In addition, the urine from a sexually mature male rabbit can have a strong odor that is unpleasant to many humans. If this behavior is allowed to continue for a long period of time, it may be impossible to completely stop this behavior. Therefore, it is best to nip it in the bud and get the little guys neutered just prior to or shortly after sexual maturity.

Prevention of Testicular Disease
Disease of the testicle is uncommon in the male rabbit, but it can occur. Most commonly we see abscesses (usually the result of bite wounds from other rabbits), hematomas (blood filled areas) and cancer.

Age to Neuter

The best age to neuter either a male or female rabbit is just before or shortly after sexual maturity. Depending on the breed, this time could range from four to six months in the small to medium sized breeds and up to nine months in the giant breeds. We do not recommend neutering rabbits younger than four months of age because the surgery may be more difficult due to the size and position of the reproductive organs. There is no health benefit to neutering earlier than four months of age. However, there is a benefit in females of neutering before two years of age to reduce the incidence of uterine and mammary gland disease.

Your rabbit should be examined by a veterinarian prior to surgery to make sure he is in good condition and ready for neutering. Sexual maturity can be gauged a number of ways including; visualizing testicles in the scrotal sacs, a well developed vulva, a mature body condition, and by behavioral changes such as urine spraying and increased aggression. Your veterinarian may recommend some simple tests prior to surgery, particularly if your pet is older or has had other medical problems. We do not recommend performing routine neutering procedures on obese animals or those with other disease because these rabbits are at higher risk for surgical complications. The weight should be reduced and any disease conditions managed prior to having a major elective surgical procedure performed.

What Happens at Neutering

When a male rabbit is castrated, the testicles are completely removed. There may either be one incision in front of the testicles through which both are removed, or there may be two incisions, one over each scrotal sac. The incisions may be left open which is acceptable if scrotal incisions were made, or closed with suture or surgical glue if the incision was made in front of the scrotal sacs. The scrotal sacs will swell within 24 to 48 hours after surgery but in another seven to ten days the swelling should be gone. The scrotal sacs will eventually shrink to a very small size over time. It is important to note that neutered males should not be put in contact with intact females for at least 3 weeks after neutering. Male rabbits can still have living sperm in ducts within the spermatic cord called the vas deferens, which cannot be removed during surgery. The sperm in these ducts can live for two weeks. Testosterone blood levels drop slowly after neutering and male rabbits will still try to mate with female rabbits for several weeks after the testicles are removed. After three weeks the sperm are completely dead. Since the testicles are gone, no new sperm are being produced so it is safe to put a male and female rabbit back together again. However, whenever you put two rabbits together, regardless of the circumstances you must watch closely for signs of aggression. Aggressive rabbits left unattended can cause serious and sometime fatal injuries.

When a female rabbit is neutered, the ovaries, the oviducts, the uterus and often both cervices are removed. Rabbits have a uterus that is made up of two long tubes with an ovary at one end and a cervix at the other. They have two cervices unlike cats, dogs, humans and many other species which only have one. An incision is made just below the umbilicus (belly button) and the uterus and associated structures are gently pulled out from the abdomen through this incision. The blood vessels supplying the uterus and ovaries are tied off with suture material, surgical clips or a laser and the reproductive organs are removed. The incision is sutured with two to three layers of suture material. Since rabbits have incisors that are excellent at cutting through many materials, we find it beneficial to bury the final row of sutures under the skin so they are not accessible. In this way the rabbit has nothing to chew on or pull out. These sutures dissolve eventually over several weeks and there are no external sutures to remove.

Some veterinarians are now advocating the removal of only the ovaries in female rabbits less then 2 years of age.  These veterinarians argue that uterine cancer usually occurs after two years of age and the removal of only the ovaries is a shorter and less invasive surgery and thus less stress on the rabbit.  This is still a controversial topic because it is difficult to know at exactly what time uterine cancer may start at the microscopic level.  Exotic animal veterinarians will be looking carefully over the next few years at these ovariectomy cases to see if uterine cancer was prevented during the life of the rabbit.  Consult with your veterinarian on this topic so you can make an informed decision.  However, if you have acquired an adult rabbit and you do not know the exact age of the rabbit (such as when adopting from a rescue), I highly recommend having both the uterus and the ovaries removed to be on the safe side.

Postsurgical Care 

It is important after any surgery to check the surgical site at least twice a day for any signs of bleeding, unusual swelling, discharges or opening of the wound. Many rabbits will be off feed for 24 hours after surgery, but this should gradually return to normal over the next two to three days. In addition, some rabbits will have unusual stools for a day or two including soft stools, clumped stools, and irregularly shaped or small stools. If your rabbit is acting very uncomfortable, is extremely lethargic, is not eating at all, is not producing any stools or is unwilling to move, contact your veterinarian immediately. Your veterinarian should prescribe a post-surgical pain medication for one or more days for your pet, which will help ease discomfort and shorten the recovery time. It is usually not necessary to use an antibiotic after a routine neutering. 

These timid and social pets are fun to watch performing their natural behaviors of burrowing, searching for food, and playing. Unlike their wild counterparts that are typically nocturnal, pet rats and mice have periods of activity both day and night. Rats and mice are inexpensive, easy to care for, and responsive to handling.

Diet for Rats and Mice

As with any pet, good quality food and clean, fresh water must be provided at all times. In the wild, these animals feed on leaves, seeds, roots, fruits and insects. Pelleted rodent rations are recommended for feeding in captivity, which are processed as dry blocks or pellets. Typical maintenance diets contain about 14% protein and 4% to 5% fat, while diets for growth and reproduction contain 17% to 19% protein and 7% to 11% fat. Seed diets are also formulated for mice and rats, but these diets should only supplement the basic rodent pellet as a treat item. Rodents prefer sunflower-based diets to pellets, but these seeds are low in calcium and high in fat and cholesterol. When fed exclusively, seed diets can lead to obesity and nutritional deficiencies.

The pet’s appetite should be monitored closely. Many factors affect the rodent’s food intake, including the ambient temperature, humidity, food quality, breeding status, as well as the pet’s health status. On average, an adult mouse will consume about 15 gm of feed and 15 ml of water per 100 gm body weight daily. Comparatively, an adult rat will consume approximately 5 gm of feed and 10 ml of water per 100 gm body weight daily. Rats and mice typically eat at night.

Water should be provided in water bottles equipped with sipper tubes. The sipper tube keeps the water free from contamination. The tubes must be positioned low enough to allow the pet easy access.Inadequate water consumption leads to dehydration, lower body weight, infertility and death. These rodents drink only a fraction of the total bottle volume, but the bottle should be emptied, cleaned and refilled with fresh water daily.

Handling and Restraint of Mice & Rats

Pet rodents become tame and seldom bite when properly restrained and accustomed to handling. Be careful, however, when approaching a nervous or frightened pet. Also, it is best not to disturb a sleeping animal because most are usually quite cranky when awakened. Some rats can be very territorial of their cage, and these should be coaxed out of the cage before being handled. Mice housed individually may be more aggressive and apprehensive than those housed in groups. Most pet mice and rats enjoy being handled when away from their cage.

Rats and mice can be easily picked up by scooping them into a can or cupped hands. They can then be moved out of their territory to a neutral area. Mice can also be lifted by grasping the base of the tail. Rats can be picked up this way, but be careful not to injure them due to their larger size. For any rodent, never pull on the tip of the tail because the skin can easily tear and become stripped from the tail.

A mouse can be further restrained by placing it in a rough or wire surface and grasping the scruff of the neck using a thumb and forefinger. The rest of the body can then be restrained by trapping the tail between the palm and little finger of the same hand. This position allows for close examination and treatment.

Rats can be restrained by grasping over the back and rib cage, while restraining the head with a thumb and forefinger positioned on either side of the neck. To initially pick up a rat, it may be necessary to grasp the tail base as suggested above. Rats do not respond well to scruffing by the nape as described for the mouse, but it may be necessary in some cases.

Pet Rodent Housing

Several types of cages are available which are suitable for housing small rodents. Many of these units come equipped with cage “furniture”such as exercise wheels, tunnels and nest boxes. These accessories contribute to the pet’s psychological well being. Cages should be constructed with rounded corners to discourage chewing. Rodents readily chew through wood and thin plastic. Recommended caging materials are wire, stainless steel, durable plastic and glass. Glass and plastic enclosures restrict ventilation and may lead to temperature and humidity problems. These materials are acceptable when at least one side of the enclosure is open for air circulation.

These pets thrive in solid bottom cages with deep bedding and ample nesting material. Bedding must be clean, non-toxic, absorbent and relatively dust free. Shredded paper and processed corn cob are acceptable beddings. Wood shavings and ground corn cob must be free of mold, mildew or other contamination. Cedar chips or chlorophyll scented shavings should be avoided because of association with respiratory and liver disease. At least one inch of bedding should be provided to allow for normal burrowing behavior. Cotton and shredded tissue paper make excellent nesting materials.

Adult mice require a minimum floor area of 15 square inches and a cage height of 5 inches. Rats need at least 40 square inches of floor space and a minimum of 7 inches in height. Breeder mice and rats require much larger areas. Optimal temperature range for these pets is between 65 to 80 degrees Fahrenheit, with a relative humidity of 40 to 70%. Twelve hour light cycles are preferred, with most rodents being more active during the night.

Pet rats and mice can be housed singly or in groups. These rodents are colony oriented by nature. However, occasionally an overly aggressive mouse or rat may have to be caged individually. Territorial disputes also develop when the cages are overcrowded or when they lack food or water. Group cages should be provided with multiple food and water sources.

As a rule of thumb, the cage and accessories should be thoroughly cleaned at least once weekly. An exception to this schedule is when newborn babies are present, then wait until they are at least 10 days old. Other factors that may require increased frequency of cleaning are the number of animals in the cage, the type of bedding material provided, and the cage design and size. Cages are sanitized with hot water and non-toxic disinfectant or detergent, then thoroughly rinsed. Water bottles and food dishes should be cleaned disinfected daily.

Sexually mature mice and rats need to be properly paired to avoid fighting and permit successful mating. Adult male mice often fight when caged together, especially in the presence of females. Therefore, a single male mouse should be housed with one or more mature females. Rats, on the other hand, usually can be caged in mixed groups of males and females without aggression.

Female mice become sexually mature at about 50 days of age. They have an estrous (“heat”) cycle of about every four to five days throughout the year, unless they are bred. Female mice are usually receptive to males for about 12 hours of this cycle, typically at night. They also have a fertile postpartum estrus, which means that they can be bred within 24 hours after giving birth.

Gestation in mice lasts approximately three weeks, but can be up to ten days longer if the pregnant female is also nursing a litter. Litter size averages 10 to 12 young. Small litter size is common with a female’s first litter or older females. New litters should not be disturbed for the first few days to minimize injury or abandonment by the mother. Baby mice are weaned at about three weeks of age.

Female rats become sexually mature at about 65 days of age (although some rats can get pregnant at 35 days, so the sexes should be separated at 5 weeks to prevent early pregnancy). They have an estrous cycle of about every 4 to 5 days throughout the year. Breeding usually occurs at night during a 12 hour period of receptiveness to the male. They also have a fertile postpartum estrus, and can be bred within 48 hours after giving birth. However, unlike mice, this usually does not occur because the male should be removed from the cage prior to the female giving birth to avoid injury to the pups by the male.

Pregnancy lasts about three weeks in rats as well. Litter size averages 6 to 12, but smaller litters are common as described for mice. The female and her litter should not be disturbed for the first few days after birth, because a stressed female rat may injure or destroy her pups. Rats are weaned at about three weeks of age. The female will resume her normal estrous cycle within 2 to 5 days after the young are weaned.

DISEASES

Chronic Murine Pneumonia (Murine Mycoplasmosis)

Mycoplasma pulmonis is a very elusive bacteria that causes one of the most common and serious infections of rats and mice. The organism is difficult to isolate by standard laboratory culture procedures. As a result, a presumptive diagnosis is typically made based on the patient’s signs and symptoms.

Signs of mycoplasmosis include sniffling, sneezing, labored breathing, squinting, red-brown tearing, and a rough hair coat. If the inner ear becomes infected, a head tilt and neurologic signs develop. In addition to respiratory signs, a genital infection may occur. Manifestations of the genital form include infertility, embryonic resorption, uterine bleeding, and small litter size. Compromise to the respiratory tract by other bacterial or viral infections or exposure to inhalant irritants can increase the severity of mycoplasmosis. The disease runs a chronic course, which may result in death if not treated early.

Antibiotic therapy should be initiated at the first suspicion of infection. Due to the chronicity, long term treatment by antibiotics in the drinking water may be necessary to suppress the infection. Severely affected individuals may need injectable medications and extensive supportive care. In addition, secondary infections with other oraginsms is common, sometimes requiring the use of multiple medications. The goal of therapy is to reduce the severity of symptoms, but complete elimination of the infective bacteria is practically impossible.

The disease is highly contagious. The bacteria is spread by direct contact with affected individuals or from an affected mother to her unborn young while still in the womb. Transmission usually occurs through respiratory aerosol and sexual activity. rabbits, guinea pigs and other rodents can serve as carriers of the disease without exhibiting clinical signs. Other mice and rats can also serve as carriers. It is extremely important to restrict contact between mice and rats of unknown health status until a quarantine period has elapsed. A quarantine period of four to six weeks is recommended. Any animal exhibiting even the slightest signs of respiratory illness should remain isolated.

Respiratory Infections in Rodents: Sendai Virus

The Sendai virus causes one of the most significant and severe respiratory infections of laboratory rodents. Suckling and weanling mice are most commonly affected, posing a serious problem to mouse colonies. Other affected species include rats, hamsters, guinea pigs, and swine. It is unlikely for a pet mouse to become infected unless it was acquired from an affected colony.

Signs of infection are usually expressed in nursing mice, while affected adult mice rarely show symptoms. Signs include labored breathing, chattering, rough haircoat, weight loss, and death. Secondary bacterial infections often worsens the disease, resulting in a higher death rate. Sendai virus infections are usually subclinical in other susceptible rodents, but these species may be a source for infection in young mice.

There is no specific treatment for this disease. Supportive care and treatment of secondary bacterial infections may lessen the severity of signs. A vaccine is available, but it is only practical for use with large colonies of affected mice. Prevention involves selecting pet mice from a Sendai virus-free source and keeping them isolated from mice of unknown backgrounds and other susceptible rodents which may carry the disease.

Sialoacryodenitis in Rats

Rats are the natural host for this highly contagious viral disease. The disease is usually self-limiting in young rats. Recently weaned mice may also be affected. The disease is spread from affected individuals through respiratory aerosol or direct contact with respiratory secretions. Infected rodents carry and secrete the virus for about seven days.

Signs are variable depending on the age and immune status of the affected rat or mouse. The most serious signs are seen in 2 to 4 week old rats with no maternal antibody protection. Initial symptoms include squinting, blinking, and rubbing of the eyes. Sneezing and swelling in the neck area develop later. Finally swellings below or around the eyes, bulging of the eyes, production of red-brown tears, and self-trauma to the eyes are noted. Respiratory signs may be present, especially if complicated by Sendai virus or murine mycoplasmosis.

Tyzzer’s Disease in Rodents

A common infectious disease of rodents is Tyzzer’s disease, caused by a bacteria (Bacillus piliformis) that infects living cells. The disease causes a high death rate in young, stressed rodents; particularly mice and gerbils. Clinical signs are nonspecific, but primarily appear as ruffled fur, lethargy, hunched posture and poor appetite. Diarrhea may also be present. The disease causes changes in the heart, liver lymph nodes and digestive tract which can be observed at necropsy.

Prevention is the key to this disease. Strict sanitation and minimal stress greatly reduces the occurrence of this disease in colony situations. This disease can be carried by apparently normal looking rodents which can cause disease in others. Tyzzer’s disease usually affects rodents that are stressed by weaning, shipping, and adjusting to new environments. Thorough sanitation prior to introduction of new animal is important in preventing outbreaks.

What Causes Myxomatosis?

Myxomatosis is caused by the myxoma virus. This virus occurs naturally in Sylvilagus species (cottontails/related rabbits) in the Americas, but is generally harmless to these rabbits. It was purposely introduced into such places as Europe and Australia to reduce numbers of wild European rabbits. The virus can spread from these wild sources and cause disease in any breed of pet rabbit.

There are many strains of the myxoma virus, some of which are more severe and fatal than others. For example, the Californian myxoma virus in the Pacific states of the U.S. and the Baja Peninsula in Mexico is particularly deadly, estimated to kill over 99% of rabbits it infects. There are similarly severe strains in Europe and Australia, but also weaker strains with death rates around or below 50%.

How is Myxomatosis Transmitted?

• Bites by blood-sucking insects (e.g., mosquitoes, fleas, flies, fur mites)
• Direct contact with an infected rabbit
• Contact with material contaminated by an infected rabbit (e.g., food, bedding, water bottles)

What are the Signs of Myxomatosis?

1. Reddened eyelids and eyes
2. Discharge (may be milky) from the nose and eyes
3. Swollen eyelids, nose, lips, ears, face, anal/genital region
4. Skin nodules or lumps
5. Drooping ears
6. Purple spots on the skin
7. Lethargy
8. Fever
9. Reduced appetite
10. Weight loss
11. Trouble breathing
12. Convulsions
13. Coma
14. Death

Note: While some rabbits may show obvious and severe signs of illness, other rabbits may show only minor or even no symptoms, but could still die.

How is Myxomatosis Diagnosed?

• Clinical signs
• Lab tests, which include:
  • Examining affected tissues under microscope
  • Detecting myxoma virus in biopsies or swabs from eyes/nose

How is Myxomatosis Treated?

Because myxomatosis tends to be a severe and fatal disease, veterinarians will often recommend euthanasia of a sick rabbit. In some situations attempts may be made to treat the patient, but unfortunately these efforts are rarely successful. 

Treatment may consist of:

1. Keeping rabbits warm
2. Assisted feeding
3. Intravenous fluids (fluids administered through the blood)
4. Antibiotics to treat secondary infections
5. Pain relievers
6. Isolating the sick rabbit from other rabbits

The rabbit’s progression of symptoms, response to treatment and quality of life will all be monitored and play a role in decisions to continue treatment or euthanize.

How can Myxomatosis be Prevented?

• Vaccines are available in some countries (not in the U.S.); 100% protection is not guaranteed
• Quarantine new rabbits
• Prevent contact between pet rabbit and insects/wild rabbits by:
  1. Keeping pet rabbit inside
  2. Using insect screens in outdoor rabbit enclosures
• Isolate rabbits suspected or confirmed to have myxomatosis

Most hamsters are best kept as solitary pets, particularly if they’re Syrian hamsters, although occasionally bonded pairs may be compatible, particularly of the dwarf species.

Recommendations vary regarding size of hamster cages, but more space is better. One published study found the smaller the cage, the more stressed out the hamsters were. A single hamster should be housed in nothing smaller than a 20-gallon tank, but at least a 40-gallon tank would be better.  Bedding should be deep and absorbent, but not made of wood-based materials. Recycled paper products such as CareFRESH brand bedding are ideal. Scooping out waste materials daily and changing the entire cage weekly will keep the environment healthy and minimize odors.

Hamsters prefer to have secluded areas in which to sleep, so plastic hideaways or things like flower pots laid on their side, are recommended for them to nest in. They will often take their treasured items into their nesting or sleeping areas. Paper towels are often a prized bedding material, and inexpensive and easy to replace when it becomes soiled.

As playful and intelligent creatures, they need items for environmental enrichment, such as solid wheels (not the wire wheels that can result in leg fractures) and toilet tissue cardboard rolls for exploration. Chew toys such as wood from apple trees and dog rawhides are popular. Daily handling is important both from a stimulation standpoint, but also to help keep them tame and make them a little more friendly. 

Hamster urine has a strong smell, but if the cages are cleaned daily, this can be minimized. Cages should be large and well ventilated. Wire caging with narrow bars allows for good ventilation and prevents escape, but many people choose aquariums for safety reasons.

Average life expectancy for a pet hamster is approximately 18 months for the dwarf species, and up to 36 months for the Syrian species.

Diet

Although the hamsters would perhaps disagree, the staple diet should be made up of commercial pelleted rodent block, with all of the other items used just as occasional treats and snacks. This diet can be supplemented with small amounts of healthy people foods, such as fruit, vegetables, and pastas and so on, but those extras should be small in comparison to the primary staple of the rodent block. High-fat items such as nuts and seeds should largely be avoided, since they certainly can cause disease in hamsters over time. Also, avoid dried fruits and vegetables.

Remember though, any changes or any additions made to rodent diets should be done slowly to help avoid diarrhea, something that hamsters are certainly quite prone to.

Medical Issues

As a prey species, hamsters unfortunately tend to hide illness, so when illness is apparent to the owner, in reality they probably have been sick for an extended period of time. Most hamsters are significantly ill by the time they see a veterinarian. Keep in mind that hamsters are nocturnal and most clinic hours are during the day, resulting in a very grumpy patient.

Hamsters are capable of delivering a swift and painful bite, so it is always best to allow the animal to fully awaken prior to handling, and approach it slowly and gently. This goes for handling your pet at home and for your veterinarian.

Hamsters are prone to quite a number of diseases.

Bladder stones are not uncommon in hamsters. This often includes difficulty and pain on urination, frequent urination, and bloody urine. These stones may be felt by your veterinarian and can be visible on radiographs. The stones generally do not respond to dietary changes, Most commonly, however, bladder stones will require surgical removal.

Cardiac disease is a common condition, particularly in older female hamsters, and appears to be associated with amyloidosis in which amyloid proteins get into the organs and tissue, causing them to function incorrectly. Congestive heart failure, with secondary left atrial thrombosis, is the classic presentation. Clinically, the history includes weakness, lethargy, difficulty breathing, and occasionally sudden death. When first seen at the clinic, the hamster often has difficulty breathing, a rapid heart rate, and is bluish due to lack of oxygen. Treatment is palliative and aimed at symptomatic therapy, but is frequently unrewarding since congestive heart failure is often very advanced at the time of diagnosis.

One of the most common issues for hamsters is skin disease, which is not as common in hamsters as in many other pet rodent species. Be aware, though, of normal hairless (alopecia) patches, particularly over the flanks of male hamsters, which are called scent patches and are not lesions. Often the owner suddenly notices them and mistakes them for skin disease. When in doubt, look for symmetry within the patch—they are generally smooth and egg-shaped—and for a matching patch on the opposite side. Other than these false lesions, the next most common skin disease associated with hamsters is bite wounds.

Occasionally hamsters will develop ringworm, which can be diagnosed by a fungal culture. In addition to initiating other local or systemic therapy, it is important to look for other underlying causes of illness.

Notoedres may be causing dermatitis in the ears, face, feet, and tail. Diagnosis is made by identifying the mites and skin scrapings. Treatment is often with ivermectin or selamectin. 

Lymphocytic choriomeningitis virus is a condition to be aware of due to its significant potential.to share it with other species, including people (zoonotic). In most instances it is not noticed in hamsters and many will clear the infection on their own. Others, however, will continue to shed large quantities of virus in the urine and be a source of human infection. This RNA arenavirus can cause a chronic wasting disease in hamsters, presenting with weight loss, decreased reproductive abilities, seizures, and depression. Diagnosis is based on pathology and serologic ELISA testing or IFA testing. There is no effective treatment, and infected animals are generally euthanized due to the high risk of zoonoses.

Many hamsters get diarrhea, and there are quite a few underlying potential causes. These are generally collectively referred to by owners as “wet tail,” and the differential diagnoses include Tyzzer’s disease, which is caused by clostridium; salmonellosis; E. coli; antibiotic-associated enterocolitis, and intestinal parasites.

One of the most common underlying reasons is proliferative enteritis or ileitis (inflammations in the GI tract) seen in young hamsters shortly after transport to the pet store or to the new home, as well as older hamsters with other diseases. The causative agent for proliferative ileitis is a Lawsonia bacteria. Overgrowth of this bacterium is precipitated by recent transport, overcrowding, diet change, and stress. It is associated with sudden onset acute watery diarrhea, stomach pain, and dehydration, and is seen most commonly in younger animals and immunosuppressed or concurrently ill animals. There is typically a high rate of illness and death associated with the condition.

Treatment in the generic case of wet tail is generally supportive, and will usually include giving fluids and antibiotics. Prognosis is guarded for severely affected animals and older animals; those with an unclear underlying cause should be closely examined for concurrent diseases. This is a contagious process, so affected animals should be quarantined.

Cancer processes are common in older pet hamsters, with endocrine and alimentary tumors being the most prevalent, and adrenocortical adenomas being one of the more common. Adenomas are benign, but they can cause problematic side effects even they don’t tend to spread elsewhere in the body. The most common malignant tumor associated with hamsters is lymphosarcoma. Older animals with lethargy, weight loss, dermatitis, and/or patchy alopecia should be screened for potential cutaneous lymphosarcoma. As with other species, some success with chemotherapy has been reported. A variety of other benign and malignant tumors can be seen. As with other species, a complete workup including biopsy is necessary to establish a diagnosis, prognosis, and treatment plan. 

In the right environment and with the right people, hamsters make great pets as long as you provide proper nutrition and care.

Wild rats are known to carry pathogens including leptospirosis, toxoplasmosis, Yersinia, and Campylobacter in addition to other conditions. Fortunately, zoonotic disease transmission from pet rats is uncommon.

Despite those different perceptions, rats are quiet and easy to care for, have minimal odor, and are affectionate and friendly animals. With adult supervision, they make excellent pets for children. However, they’re not maintenance free and bringing a pet rat into your home comes with a commitment to provide a large enough cage; time to regularly clean and launder the cage accessories; daily social time, and a high-quality diet.

As pets, with care and attention, rats are gentle, calm, mild mannered, and rarely bite. Although short lived, they are appropriate first pets for young families providing that there is always adult supervision. The most common rat kept as a pet is a domesticated brown rat known as the fancy rat. Over time, breeding has resulted in a variety of different coat colors and types, and fancy rat breeders and clubs are common.

Also, particularly when the rat is to be a pet for a child, mature animals are less likely to explore the world with their mouths; in other words, they tend to be a little less nippy, and are often not quite as fast moving, and therefore, a little easier to handle. On the downside, animals coming from a previous home may come with bad habits including poor dietary preferences, and some retraining may be necessary.

Rats are social animals living in groups in the wild. They appear to derive great enjoyment from social interactions with one another as well as with humans and appear most content when housed in small groups.

Habitat

Unfortunately, many of the basic husbandry needs of rats are overlooked, harkening back to the days of small plastic hamster cages with tubes, wood cedar bedding and food bowls filled with seed and dried fruit. Sadly, this traditional care has led to countless diseases in our pet rats over the years and resulted in significant suffering and pet mortality. In my practice, we spend a generous amount of time counseling our rodent owners on proper husbandry and care of their animals. This hopefully helps not only the animal at hand but generations of pets that these owners may eventually have.

Habitat size must be increased to accommodate group size, but even an enclosure housing a pair of rats can result in a content rat family without requiring too much room. Rats will sometimes exhibit aggressive behavior towards one another, particularly when originally introduced. However, a bonded pair will sleep together, play together, wrestle, groom one another, have squabbles, and develop a variety of communication skills.

Without good basic care, rat health is a house of cards that will easily be upset with even the most minor of infections.

This helps prevent the feet from injury on the wire bottom of the cage, and allows the rat to create a comfortable nesting area. Solid floors are ideal, if available. 

There should be multiple sleeping areas including enclosed sleep boxes, hammocks, and soft, blanketed material. Many rats will readily litter train and each story of the cage should have a corner box available for them. The litter boxes or cage base should be covered with paper-based recycled bedding such as CareFRESH bedding. Avoid wood-based and scented bedding as they can contribute to respiratory disease as well as elevate liver enzymes.

A rat cage that is kept clean will not have a strong odor, and if you feel the need to have scented bedding, this is a sign that the cage is likely not kept clean enough. Bedding should be washed at least weekly and more often if there are multiple rats. Boxes are best changed daily and the remainder of the cage spot cleaned as needed. Rats in general are very clean creatures and will thrive in a clean environment. 

As we have discussed briefly, rats are social creatures. Not only do they bond with their human owners, but they also establish a complex and rich series of community relationships and behaviors. Although rats are frequently kept as singleton pets, they are likely to be more content and enriched when living in small groups. A bonded community of three to four individuals generally appears to be ideal. This can be either as single-sex environment or a mixed group of altered animals.

When intact animals are housed together, particularly males, they need enough room to prevent fighting and establishing territorial aggression. Some dominance is to be expected in any group of animals, but in general most rats appear to settle their disputes amicably.

Wrestling and grooming behavior within a group is common and should not be mistaken as aggression. Adequate space is a solution to many inter-rat problems, and so when in doubt, provide the largest cage you can and as much out-of-cage social interaction time as possible. 

What to Feed

Rats are nutritional omnivores and can eat and digest a wide variety of foods. Unfortunately for the rats, pet food manufacturers have taken advantage of this fact to provide a wide variety of foods that are appealing but do not provide the necessary nutritional basics; in other words, it’s junk food.

In general, the staple of a rat’s diet should be made up of high-quality pelleted food such as that made by Mazuri. These foods are most commonly referred to as ‘rat block’ or ‘rodent block’. They should not contain any colored pellets, nuts, dried fruits or vegetables, or seed bits.

Rat block should comprise 80% to 90% of the overall caloric intake for an animal. Many rats are fed some variety of seed, dried fruit, and nut-based diets. Unfortunately, these diets are often high in fat, and rats can become obese even when eating a healthier diet. Over time, these diets can lead to organ disease, a weakened immune system, skin disease, and obesity.

The higher quality rat food brands have been formulated to completely meet the rat’s nutritional needs with no significant excesses or deficiencies, and they do not allow the rat to pick and choose its favorite diet components. Although not visually appealing to us and perhaps not as popular as the seed-based junk foods marketed for rats, these pelleted diets are vastly superior nutritionally, the equivalent of a salad instead of candy.

Have a thorough diet review with your veterinarian so you can help prevent illnesses wherever possible. The risk of both kidney disease and obesity-related diseases can be reduced strictly by calorie and protein control alone.

Not only is the content of the diet important in the health and wellbeing of the pet rat, but the amount is also important. Rats who can eat whenever they want have been shown to have higher incidences of mammary, pituitary and pancreatic cancers. Moderate caloric restriction has been demonstrated to reduce the likelihood of cancer, particularly with tumors that have an endocrine influence. Therefore, a moderately restricted, high-quality diet yields multifactorial benefits in the health of pet rats.

A variety of healthy treats and supplements should be offered to the pet rat. When you begin to offer these extras, do so slowly in order to avoid digestive upset. Healthy fresh foods that can be given include small amounts of cooked beans, peas, corn, dry or cooked pasta, squash, carrots, green leafy vegetables, breads, and small amounts of other fresh fruits and vegetables. Occasional snacks of nuts, lean meats, and eggs are also appropriate, but rats are sensitive to excesses of proteins in their diet and high-protein snacks should be kept to the occasional treat only.

Portions should be appropriate for the size of the rat: a pinky fingernail-size portion of food is similar to an entire plate of food for an adult human. Although rats adore sugary and salty treats, avoid them.

Basically, if it would be considered a healthy snack for a human, it will likely also be a healthy snack for a rat as long as portion control is appropriate. Rats are truly an example of ‘you are what you eat.’ With their already too-short life spans and a tendency towards disease, we owe it to them to provide as much of a nutritional head start as we possibly can.

Health

Despite the emphasis on overall husbandry and preventative medical care, the realistic truth is that the vast majority of rats seen by veterinarians are pretty sick. That being said, many of the conditions our little rat friends are prone to are controllable and some are even curable. They are surprisingly sturdy patients and can tolerate a wide variety of both medical and surgical procedures.

Although rats in general are hardy little creatures, they are certainly prone to a number of conditions. Some of these, such as renal disease and obesity-related conditions, can be prevented with good husbandry and diet. Others, such as tumors and respiratory diseases, are a combination of genetic predisposition, exposure, and environmental causes. Even though an animal may have a large and dramatic tumor, there are often options to improve the animal’s quality of life even when there is no cure.

Mammary adenomas are the most common mammary tumors found in rats and can be seen in males and females. Spaying can significantly reduce their occurrence in females.  Although they have been reported in rats of all ages, they are most common in animals older than 18 months of age. Some of these adenomas can be extremely large and carry a rich blood supply. Fortunately, this completely benign and encapsulated mass is significantly more common than its cousin, the mammary adenocarcinoma. Mammary adenomas can be deceptive since rats are essentially walking mammary glands. There is mammary tissue from the chin to the base of their tail. Any skin mass could potentially be a mammary adenoma.

Fortunately, rats do very well when having these tumors surgically removed. As a rule, fibroadenomas tend to remain localized and are not invasive. They can, however, be extremely large, sometimes approaching the size of the rat itself. Tumors of this size can be a surgical challenge since essentially you are removing the rat from the tumor. If the tumor is not completely removed, they will often regrow. Still, most rats will benefit from debulking large tumors.

Spaying just as you would any dog or cat at a young age and then restricting calories or not allowing a free-fed diet can go a long way toward preventing mammary fibroadenomas. 

Mammary tumors are dependent on estrogen and prolactin concentrations and spaying markedly reduces their incidence. Early age spaying may virtually eliminate the incidence of later development of mammary masses, and even spaying at the time the tumor develops may prevent a recurrence.

Free-fed rats have a higher incidence of pancreatic, mammary, and pituitary tumors than rats fed in identical diets with moderate quantities. High-caloric intake also enhances tumor growth and the endocrine-based tumors, particularly mammary masses and pituitary masses, appear to be the most influenced by caloric intake. Therefore, feeding a calorically restricted, high-quality diet is crucial to preventing mammary masses and their recurrence. Practicing preventative medicine makes a positive difference.

Fortunately, when it comes to fibroadenomas, we have good treatments to help most pets. Rats make surprisingly hardy surgical candidates. They do, however, tend to self-mutilate their incisions. Surgery is the easy part of treatment. It’s the two weeks after the surgery that’s the hardest part. When we make it to suture removal, I consider the treatment to have been a success.

Pituitary masses are relatively common in rats and appear most frequently in female animals between 13 and 24 months of age. These are occasionally seen in male animals or younger animals but are much more frequently seen in females. Even in the normal animal, the female has a larger and heavier pituitary gland. Females that have been spayed don’t have pituitary masses as often as rats who are intact. Signs are extremely variable and often continue to change. Most commonly, however, these tumors are benign; they rarely metastasize and are a relatively slow-growing tumor. A number of factors influence pituitary tumors including age, genetics, hormonal status, spaying and neutering, injury, infections and so on. Unfortunately, the location of the tumor and the pituitary gland makes surgical removal a poor option. However, targeting the symptoms of most clinical concern for the patient can lead to significant palliation of the clinical signs and improve quality of life for the patient.

Respiratory diseases are one of the most common reasons pet rats to see the veterinarian. Infections are endemic in the rat population and many animals are infected at the time of purchase or adoption by the owner. Periods of immunosuppression, stress, or concurrent infections can result in the sudden appearance of clinical signs. There are several common underlying causes for infection, including bacterial, viral, fungal, and parasitic diseases. Infections frequently have significant and severe secondary results including pneumonia, abscesses, empyema, pleural effusion, and bacteremia. Non-infectious causes of pneumonia, such as aspiration pneumonia or chemical irritants resulting in inflammation and pneumonia, are seen.

Of all the reasons for pneumonia in rats, the most common is the bacteria Mycoplasma pulmonis. Mycoplasma differs from the most common bacteria because they lack cell walls but are enclosed by a lipid protein cell membrane. They’re not considered to be either gram-positive or gram-negative. Because of these facts, some antibiotics such as penicillin and cephalosporins don’t against mycoplasmas.

Clinical signs vary depending on the virulence of the strain involved, the site of infection, the age of the animal, and concurrent disease. For patients experiencing upper respiratory tract disease, clinical signs are generally mild and include sneezing, snuffling, squinting, and porphyrin staining around the eyes and nose. In fact, many owners take their rat to the doctor thinking that there’s eye disease, complaining that the animal is squinting and bleeding from the eyes. These rats may also have signs associated with an inner ear infection including head tilts, rolling, face and ear rubbing, and ear pain. Patients may also have signs of lower respiratory disease including rattling or moist breath sounds, labored breathing, chattering, coughing, and gasping. These animals are often clinically ill and may appear lethargic and/or have a poor appetite, poor coat, weight loss, hunched posture, and grumpy behavior. Some rats don’t have any signs at all. Pups may be infected before birth.

At this time, there is no cure for mycoplasmosis, and it requires long-term management. At best, we try to minimize the clinical signs, reduce concurrent diseases, improve husbandry, and look for the overall quality of life of the patient.

Hedgehog Personality

Hedgehogs are small animals, but a large addition to the household.  Not only do they have large personalities, but also they require a lot of care, more than your average dog or cat.  Hedgehogs that are acquired when young may be very social if handled regularly and gently, but some never adjust to handling and are shy and skittish their entire lives.  Many adults may be nervous when handled, ball up and hiss, or hide. 

As a rule, hedgehogs rarely bite. They are nocturnal, so expect them to be a tad bit grumpy during daylight hours, but up and ready to rumble overnight. Plan to keep them in an area where they do not keep the entire family up at night!

Some hedgehogs do something known as “anting,” where they find something new in the environment, “taste” it, and then begin to hypersalivate, creating a foam. They promptly then paste this spit all over themselves. This is a normal behavior, and nothing of concern – just a hedgehog way of checking out their surroundings! When loose in the house, hedgehogs often hide in corners, under furniture, and spend time foraging for spiders and insects in the house. They may be somewhat destructive, digging in carpets, household plants, and rummaging around in areas where you’d prefer not to have a hedgehog rumbling about!

Housing

Hedgehogs are not particularly social creatures, and generally prefer to be housed alone rather than with other hedgehogs, so a separate enclosure for each hedgehog is recommended. They are not strong climbers, but may scale wire and then fall and hurt themselves, so smooth-sided containers with lots of ventilation are recommended. Many people are able to build suitable caging, but be sure that it is large (at least 2 feet by 3 feet per hedgehog), easy to clean, and has lots of healthy air flow through it. As a rule, hedgies prefer quiet, dark environments and are easily startled if housed in areas with bright light and loud noises, such as in a laundry room. Most hedgehogs aren’t big believers in litter pans, so expect to do a lot of cleaning. Bedding such as recycled paper products work well and are easy to spot clean as well as change out regularly.

One commonly overlooked fact is that hedgehogs do best in warm environments and should be kept between 75-85°F (24-30°C).  In most households, supplemental heat in the form of a heat lamp or chew-proof heating pad must be provided.

Hedgehogs like to have toys and will readily use boxes, side-turned flower pots, tubes to explore, exercise wheels with solid floors, and warm shallow tubs for swimming. Many hedgehogs will entertain themselves for hours if provided insects in their cage to hunt, such as live crickets, dubia roaches, and mealworms are valuable dietary additions plus sources of exercise and stimulation.

Feeding

One of the most frequent health problems we see in hedgehogs is obesity; many animals simply get too much food and too little exercise. Often, they are also fed an incorrect diet. Many commercial foods on the market have little to no science to substantiate them as a good food. Hedgehogs are insectivores, not carnivores, so feeding something like dog or cat food really is not appropriate as a sole diet. 

We would like them to have a diet that is high in protein and low in fat, and recommend offering the majority of the food in the evening only when the hedgehog is most active. Leaving food available all day encourages snacking and weight gain. An ideal diet mix for one day would include something along the lines of 2 heaping teaspoons of a bird of prey diet or a commercial insectivore diet, a teaspoon of low-fat high-quality cat food, a teaspoon of mixed vegetables, and 6-8 insects (include a variety of crickets, dubia roaches, phoenix worms, and mealworms).

Avoid high sugar items such as carrots, apples, bananas, raisins, and so on, and concentrate on dark green nutritious vegetables. There is a possibility, although not proven, that raisins or grapes may contribute to kidney injury. Likewise, insects should be fed as a variety and not just limited to crickets and mealworms, or whatever the local pet store carries all the time. Much of hedgehog food may need to be special ordered, as it often is not readily available.

Routine Home Care 

Hedgehog toenails grow quite rapidly, and they should be trimmed at least once per month.  Also, they are prone to dental disease, particularly if they are fed sweet or sugary fruits or treats; regular tooth brushing can help keep the teeth healthy and minimize the amount of professional cleaning required.  The other critical things to watch for at home that can help minimize or prevent a lot of health problems is maintaining a healthy diet, preventing obesity, being sure that the bedding remains clean and dry, and maintaining a heated environment year round to help prevent chilling.

Health Problems

Unfortunately, hedgehogs do not tend to be particularly long lived; although they have been reported to live 6-10 years in captivity, in reality most do not survive much past 3 years. They are also prone to a large number of health problems, the most notable ones being cancer and neurologic problems (Wobbly Hedgehog Syndrome). Many of the other routine diseases we see, such as obesity, dental disease, trauma, and pneumonia can largely be prevented with good husbandry care at home.

Be sure to do your homework before bringing a hedgehog into your home. If the hedgehog is not quite right for you, keep looking around to find a small mammal that is.

They have excellent hearing and a good sense of smell but unfortunately have poor eyesight, and therefore are prone to falling if left unattended in areas with ledges.

Mice are largely nocturnal and are often swift-moving creatures, which makes them inappropriate pets for most small children. Additionally, they may jump quickly and without warning. Daily handling is important from a stimulation standpoint and will help to tame them and make them more friendly. 

The average life expectancy for the pet mouse is approximately 18 to 24 months. Unfortunately, as a prey species, they tend to hide illnesses. Often, by the time any trouble is apparent to you, it’s probably been going on for a while. Because of this, most mice are already significantly ill when they get to a veterinarian.

Housing

Cages should be large and well-ventilated. Wire caging with narrow bars allows for good ventilation and helps prevent escape. Many people choose aquariums for no-escape safety reasons, and these must have wire mesh tops to allow for good ventilation. A single mouse should be housed in nothing smaller than a 15-gallon tank, but a 20-gallon tank would be an appropriate size for two mice.

The bedding should be deep and absorbent but not made from wood-based materials and unscented only. Recycled paper bedding is ideal. Scooping out waste materials daily and changing the entire cage weekly will help keep the environment healthy and minimize odors.

Mice prefer sleeping in secluded areas. They enjoy nesting in plastic hideaways or flowerpots laid on their sides. They will often take treasured items into their sleeping or nesting areas. Torn paper towels are often prized bedding material and it’s inexpensive to replace when it becomes soiled.

Diet and Enrichment

Commercial pelted rodent block is an appropriate diet and can be supplemented with small amounts of healthy people foods. It is wise to avoid high-fat extras such as seeds and large amounts of nuts. Introduce all foods slowly to avoid diarrhea. 

Playful and intelligent, mice like enrichment. Enrichment items are things that help mentally and physically stimulate animals and may mimic things in their natural environment. A well-outfitted mouse home includes numerous items for play and enrichment, such as a solid wheel (wire wheels can cause legs to break), an enclosed sleeping box, chew toys, and climbing toys. Toilet tissue rolls, sisal rope climbs, and cornstarch baths are favorites. Chew toys such as wood from apple trees and dog rawhides are popular.

Health Conditions

New mice should be quarantined for an extended period, even as long as four weeks, before integrating into an otherwise healthy group.

Skin diseases are common in mice and can have several underlying causes. One of the more common includes bite wounds from cage mates. Taking care of the underlying reason for the squabble will usually end this behavior. This problem may require separating the mice, providing a larger enclosure, or neutering the mice. Most commonly, infections of these wounds occur secondary to Staphylococcus species. The wounds are generally treated with antibiotics and pain medication. However, these wounds can occasionally abscess and become chronic problems that require surgery.

In groups of mice, barbering of fur is common. Affected animals show bare patches of fur although the underlying skin looks normal. Barbering appears to have hierarchal indications within the group and removing the barber often results in resolving the symptoms in the barbered mouse. Some controversy exists as to whether it is the dominant mouse being barbered or doing the barbering.

Mite infestation is another common problem. These parasites can result in the mouse scratching itself and causing severe skin irritation on the head, neck, or shoulder area. Skin scrapings can diagnose the mites and your veterinarian may see the mites on the fur. The mite’s entire life cycle is completed on the mouse, but transmission between animals is common and reinfection happens. Medical treatment, in addition to addressing any secondary bacterial infection, is generally curative.

Occasionally, a mouse appears to scratch severely for no obvious reason. This has been referred to as obsessive-compulsive itching disorder in mice. Vitamin A supplementation can help in addition to controlling any secondary bacterial infections. Ringtail is most commonly associated with low humidity conditions in young animals resulting in constrictions around the tail. In severe cases, tail amputation is often indicated.

Pneumonia frequently happens in mice as well and is often caused by a bacterial infection. Signs include upper respiratory signs such as sniffling and sneezing, and lower respiratory tract signs including labored and noisy breathing. Signs of overall illness include squinting, red-brown tears, and a rough coat. Some cases may also have neurologic signs including a head tilt.

This disease is very contagious and similar to rats with mycoplasmosis. Mice may be carriers of mycoplasmosis and yet be asymptomatic, which means that all mice in contact that show respiratory disease should be considered infected.

In addition to medical therapy, replacing their bedding daily with material unlikely to irritate the respiratory tract such as unscented recycled paper bedding can reduce clinical signs of respiratory conditions. Unfortunately, mycoplasmosis is a common and severe disease that often leads to death in pet mice.

Mammary adenocarcinomas occur in mice and can be found anywhere on the body due to the large amount of mammary tissue in mice. Unfortunately, these are more aggressive than those in rats and although they can be surgically removed, they do have a more significant amount of local tissue invasion as well as a likelihood of spreading to the lung.

Lymphosarcoma is also a common cause of tumors. Chemotherapy tends to work, but a remission time of weeks is considered a reasonable expectation.

Lastly, benign respiratory adenomas are seen in some strains of mice and older animals. White lesions may be observed on the surface of the lungs that can be large enough to show up on X-rays or other imaging.

Since mice are commonly used as models in research, much information is readily available about the cancer tendencies of this species. Unfortunately, much less information is available about the treatment options for an individual mouse.

Summary

Mice can make excellent pets for older children through adults and are affectionate, curious, and energetic pets although mostly nocturnal. Just like other pets, they have specific diet, enrichment, and housing needs that must be met for them to be happy and healthy. Talk to your veterinarian any time you have general wellness or medical concerns with your mice.

Since their domestication, several color and hair coat varieties of the Syrian hamster have arisen through selective breeding. The three basic groups which now exist include the common ‘golden’ hamster, colored short-haired ‘fancy’ hamster, and long-haired ‘teddy bear’ hamster. All three varieties are popular as pets, while the research community generally employs the basic golden hamster.

On occasion, one may encounter other species of hamsters, but these are much less common than the Syrian hamster. The smaller, dark brown Chinese hamster (dwarf hamster) is often used in biomedical research, and they are sometimes acquired as pets. These hamsters are recognized for their small size, dark brown color and black stripe down the back. The Armenian (grey) hamster and European hamster are two other species occasionally used in research, but seldom kept as pets. The information here pertains particularly to Syrian or golden hamsters because they are by far the most popular.

Diet

As with any pet, good quality food and clean, fresh water must be provided at all times. The precise nutritional requirements of hamsters have not been fully determined. In the wild, these animals feed on plants, seeds, fruit and insects. Current recommendations for feeding in captivity are pelleted rodent ration containing 15% – 20% protein. These rations are typically processed as dry blocks or pellets designed for rodents. Seed diets are also ‘formulated’ and sold for hamsters, but these diets should only supplement the basic rodent pellet. Seed diets contain high levels of fat which can easily become rancid if improperly stored. In addition, when fed alone, these diets often lead to obesity and potential nutritional deficiencies, especially calcium. Other supplements to the diet may include sugarless breakfast cereals, whole wheat breads, pasta, cheese, cooked lean meats, fresh fruits and vegetables; all fed in moderation. Hamsters eat approximately 12 grams of food daily, and usually consume the majority of this at night. Hamsters are like little pack rats that often hoard their food in a corner of their cage, making it seem as though they eat a lot more than they really do.

Water is easily provided in water bottles equipped with sipper tubes. This method also helps keep the water free from contamination. Always make sure that the tubes are positioned low enough to allow the pet easy access. Juvenile hamsters need special consideration to make sure they are strong enough to use the sipper tube as well as reach it. The average hamster drinks approximately 10 ml of water per 100 grams body weight (average adult size). Although this amount is only a fraction of the total bottle volume, fresh water should be provided daily, not only when the bottle empties.

Diseases

Proliferative Ileitis (Wet Tail)

The most commonly encountered bacterial infection recognized in hamsters is ‘wet tail’. The precise cause of the disease is not fully understood, but underlying infections with the bacteria Campylobacter fetus subspecies jejuni have been reported. Similar Campylobacter sp. are responsible for serious intestinal diseases in other animal species, such as swine, dogs, ferrets, primates and even humans. Although this agent is suspected to be an underlying cause of this syndrome, pure cultures of the bacteria cannot reproduce the disease, suggesting other predisposing factors or agents. Such contributory factors include improper diet, sudden dietary changes, overcrowding and other stresses.

This disease most often affects weanling hamsters between the ages of 3 to 6 weeks, but hamsters of all ages are susceptible. Since this is the age at which most hamsters are sold, this is a common disease encountered in recently acquired pets. The long haired ‘teddy bear’ hamster seems to be more vulnerable than the other varieties.

Death may result within 1 to 7 days after the onset of watery diarrhea. Other signs include matting of the fur around the tail, unkept hair coat, hunched stance, loss of appetite, dehydration, emaciation and irritability. Blood from the rectum and rectal prolapse may be noted in some serious cases. This is a very serious disease, with death being the most likely outcome. Due to the severity, any hamster exhibiting these signs must be examined by a veterinarian as soon as possible. Antibiotics, fluid therapy and anti-diarrheal medications will be administered to the patient. Supportive care will also be instituted. Despite all the best efforts, treatment is often unrewarding with death occurring within a couple days in many cases.

Hair Loss (Alopecia)

Hair loss can occur for a number of reasons in hamsters. This loss of hair can be due to both disease and nondisease conditions. Continual rubbing on feeders or sides of the cage as well as protein deficiency and barbering (hair chewing by cage mates), are examples of nondisease causes of alopecia. Infestation with demodectic mites is one of the most common infectious causes of patchy alopecia and scaling in hamsters. Other conditions that lead to hair loss include adrenal tumors, thyroid deficiency, and chronic renal disease. Some of these conditions may be correctable, while others are not.

Demodex mites are the most common external parasite causing problems in hamsters. The mite lives within the hair follicles and certain skin glands of their host. The presence of these mites result in dry, scaly skin and subsequent hair loss, especially over the back and rump. This disease is rarely a problem by itself. Demodectic mange in hamsters is often associated with chronic, debilitating diseases or other underlying problems. For this reason, a thorough examination must be performed on any hamster presented with mites. To confirm the presence of mites, the veterinarian may perform a skin scraping for microscopic observation. Treatment for the mites is often possible, but remember that there may be another problem, often more severe, underlying this one which must also be addressed.

Old Age Diseases (Geriatric Conditions)

Hamsters tend to have relatively short life spans when compared with other species. The average life expectancy of a hamster is between 2 and 3 years of age. For this reason, spontaneous aging diseases are not uncommon in these animals, typically after the age of one year. Two of the most common geriatric diseases of hamsters are amyloidosis (protein deposition in various organs) and cardiac thrombosis (blood clots in the heart). Treatment of these conditions involves managing clinical signs because a cure is not possible. A diagnosis of virtually any geriatric disease carries a poor prognosis.

Amyloidosis is a condition whereby proteins produced by the body are deposited in various organs, primarily the liver and kidneys. Kidney and liver failure often occurs as a result of this protein deposition. Many other organs are also affected, and the changes are irreversible. Signs of this condition include swollen abdomen, urinary problems, dehydration, poor appetite and rough hair coat. Supportive care is the only treatment since this condition is eventually terminal.

Blood clots within the heart occur at a relatively high frequency in older hamsters. This condition is known as cardiac thrombosis, and typically occurs in the left side of the heart. Many factors are involved in the formation of these clots including clotting disorders, heart failure, circulating bacterial infection and amyloidosis. Many other old age diseases occur in hamsters over the age of one year. Liver and kidney disease is not uncommon in middle age to old hamsters. Other conditions commonly encountered are gastric ulcers, tumors, and dental diseases.

Facts

• Average life span: 2 – 3 years
• Adult body weight: 100 – 150 grams (3.5 – 5 ounces)
• Environmental temperature range: 65 – 80°F
• Relative humidity range: 40 – 70%
• Age at first breeding:  males 10-14 weeks; females 6-10 weeks
• Gestation period: 15.5 – 16 days
• Litter size: 5 – 10 (average)
• Weaning age: 21 – 25 days

Handling

Hamsters handled frequently from a young age usually remain docile and seldom bite. These animals of a docile nature can be picked up gently by cupping in one or both hands and held against one’s body. Beware that even docile hamsters may bite if surprised or abruptly awakened from sleep.

Other hamsters, however, may not have received a lot of attention and handling throughout their lives, and thus may be more apprehensive and aggressive. Any animal whose personality is not fully known must be approached cautiously. The use of a small towel or gloves can assist the handler in capturing and restraining such a pet. Another method of capture involves coaxing the animal into a container (such as a can or tube), which can then be removed from the cage. Once removed from the cage, biting hamsters can be restrained by grasping a large amount of skin at the scruff of the neck. As much skin as possible must be grasped using this method because their skin is very loose. If lightly scruffed, the hamster can easily turn around within its skin and bite the handler.

Housing

Several types of cages are available that are suitable for housing hamsters. Many of these units come equipped with cage ‘furniture’ such as exercise wheels, tunnels, and nest boxes as added luxuries. Such accessories, as well as sufficient litter depth within which to burrow, are desirable for the pet’s psychological well-being. Cages should be constructed with rounded corners to prevent chewing. Hamsters will readily chew through wood, light plastic, and soft metal; so recommended caging materials are wire, stainless steel, durable plastic, and glass. Beware that glass and plastic containers drastically reduce ventilation and can lead to problems with humidity, temperature and odor concentration. These materials make suitable cages when at least one side of the enclosure is open for air circulation. In addition, make sure that the enclosure is escape proof because these little rodents are known escape artists.

Hamsters do very well in solid bottom cages with deep bedding and ample nesting material. Bedding must be clean, non-toxic, absorbent, relatively dust free, and easily acquired. Shredded paper or tissue and processed corn cob are preferred bedding. Be sure that the ground corn cob is free from mold, mildew, or other contamination before using. Shredded tissue paper makes excellent nesting material.

Adult hamsters require a minimum floor area of a 10-gallon aquarium (approximately 20 inches by 10 inches) and a cage height of a minimum of 6 inches. Female breeding hamsters require much larger areas. Optimal temperature range for hamsters is between 65 to 80°F, with babies doing best at 70 to 75°F. The relative humidity should be between 40% and 70%. Twelve hour light cycles are preferred, with hamsters being more active during the night.

Pet hamsters are generally housed singly. Mature female hamsters tend to be very aggressive towards one another and should never be housed together. Females are also larger and more aggressive than males, thus males usually need to be separated immediately after breeding. Males may also fight when housed together, but tend to be less aggressive than females.

The cage and accessories should be cleaned thoroughly once to twice weekly.  An exception to this schedule is when newborn babies are present; wait until they are at least two weeks old to disturb the cage. Other factors that may require increased frequency of cleaning are the number of hamsters in the cage, the type of bedding material provided, and the cage design and size. Clean the floor and walls with soap and water weekly. Change the bedding weekly.

Cages should be sanitized with hot water and a nontoxic disinfectant or detergent, then thoroughly rinsed. Water bottles and food dishes should be cleaned and disinfected daily. Most of the time just hot water and a mild detergent, and rinsing it afterward, is fine. Bleach kills most of the major pathogens that a hamster would create or be in contact with, so for a more thorough cleaning once in a while use a solution of 1 part bleach in 10 parts water; wipe it on, let it sit for 15 minutes, and then rinse it off thoroughly. Water bottles and bowls can be soaked in this bleach solution for 15 to 30 minutes but must be rinsed well before use. Cleaners are sold at pet stores that can be used but most are not as effective for deep cleaning as bleach.

Reproduction

The sex of hamsters can be easily determined. Mature male hamsters possess large, prominent testicles, which often alarm owners who first notice their size and mistake them for tumors. In addition, the genitourinary to anal separation is much wider in males than females, making it possible to sex young hamsters.

Male hamsters should be first bred at 10 to 14 weeks of age. Females can be bred at the age of 6 to 10 weeks. As the female comes into ‘heat’ she will begin assuming a breeding stance with her back swayed and body stretched out. When petted over her back, she will remain motionless and sway her back even further. A thin mucus will be noticed coming from her vulva on the next day of the ‘heat’ cycle, which indicates that estrus will occur two days later. For breeding, place the female into the male’s cage about one hour before dark. Closely observe the pair for mating activity or fighting. Females can be very aggressive towards males and can cause serious injuries. At the first sign of aggression by the female, remove the male; then try again the next night. Also, remove the male shortly after a successful mating has taken place.

Pregnancy is of very short duration in hamsters; lasting only 15 to 16 days. Just before delivery, the expectant mother will become restless and may discharge a small amount of blood from her vulva. Do not handle or disturb her at this time. It is wise to clean her cage two weeks following breeding, so her cage is relatively clean when babies arrive. Litter size ranges from 5 to 10 pups; larger litters are not uncommon. The pups are born hairless with their eyes and ears closed. However, they do already have their front teeth, the incisors.

Provide ample nesting material and bedding for the new mother and young. Plenty of fresh food and water should be available before the babies are born. DO NOT disturb the mother and young for any reason during the first week or two after birth. If a mother hamster seems threatened for any reason, she typically will kill and cannibalize the young. In other instances, she may stuff the young into her cheek pouches and frantically carry them around the cage looking for a safe place to establish a nest. Occasionally, pups will suffocate as a result of this activity, especially if the disturbance is prolonged.

Young hamsters usually begin eating solid food at 7 to 10 days of age, but are not weaned until 21 to 25 days. Provide food on the cage floor for the young and mother, and also have soaked, softened pellets available for them as well. Make sure that the water bottle is low enough for the weanlings to use, and that they are strong enough to use it; or provide an alternative water source during this time.

This was not always the case. In the 40s, 50s and 60s — well over half a century ago — death from anesthesia was about 1 in 400 for dogs and 1 in 260 for cats. These numbers are from referral hospitals, which are generally anesthetizing sicker patients, and that could increase the numbers over what you would expect to see in healthier pets in a general practice. There is a study from the early 2000s in the U.K. that followed mortality in a variety of practices (from general practices all the way to referral hospitals) and included dogs, cats, birds and pocket pets; in it, they found a death rate from 1 in 588 for dogs and 1 in 416 for cats. The risk has continued to drop, so that today those fatality numbers are around 1.7 in 1,000 dogs and 2.4 in 1,000 cats.

Although only statistics for dogs and cats have been created, the same improvement in risk applies to other pets such as rabbits, rats, hedgehogs, bearded dragons, and even goldfish as equipment and teaching new methods of anesthesia have improved over the years.

How does it work?

General anesthesia is given through an IV or an inhaled gas, or sometimes a combination of the two. It is similar, on a smaller scale, to a medically-induced coma. Oftentimes a sedative is given first.

It works by interrupting nerve signals in your pet’s brain and body. It keeps them temporarily unconscious: asleep, relaxed, and pain free during a procedure or surgery. It slows down automatic functions like breathing, heart rate, and circulation. During that coma-like period, brains cannot process pain, nor will the pet remember what happened during surgery.

During the procedure, the veterinarian or veterinary anesthesiologist will check some basic functions while your pet is under, such as breathing, temperature, heart rate, blood pressure, blood oxygen level, and fluid levels (as would happen in a human surgery). Monitoring doesn’t have to be done with expensive equipment, as having a trained person monitoring the depth of anesthesia as well as certain physical parameters can be just as valuable. Computerized anesthesia monitors can be used to enhance, but not replace, that person’s ability.

If those functions aren’t where the veterinarian wants them to be, adjustments in the level of anesthesia can correct them.

Monitoring doesn’t stop when surgery is over, or even when the equipment is removed. About half of the anesthesia deaths in small animals happen during the first 3 hours after surgery. The causes are usually breathing or heart problems. That makes this time critical for patient safety. Careful monitoring by a trained observer of physical variables, especially oxygenation and temperature, can help make this time period safer.

What main factors influence anesthetic risk?

Not unsurprisingly, the first is the health of the animal. Healthy patients, or patients with mild, controlled disease, are at less risk than patients who are sick. For healthy dogs, about 1 in 2,000 are expected to have a fatality and about 1 in 1000 cats would have one. In sicker patients, it would be closer to 13 dogs and 14 cats out of 1,000.

Having anesthesia in an emergency can also increase risk. That makes sense if you think about it. When you have time to plan a procedure, stabilize your patient and can schedule surgery at a time that is optimal for everyone, things go better. Having said that, the risk of anesthetic death with an emergency procedure, while higher than regular procedures, is still low.  Emergencies are emergencies because they can’t wait, and there are times that the pet will die if surgery is not done as soon as possible, such as with bloat.  

Veterinarians can decrease risk by focusing on monitoring and supportive care before, during, and after anesthesia. Preoperative planning is done with a good history, physical examination, and often baseline lab work to check liver and kidney function, among other things. Any abnormalities identified before surgery can be corrected if needed.

Follow all of your veterinarian’s pre-operative instructions exactly, including when to stop giving food the night before. Anesthetized patients lose their ability to swallow. If there is food in the stomach, the pet could vomit while under anesthesia or soon afterwards. If vomiting occurs before the swallowing reflex comes back, the vomited material can enter into the lungs, causing aspiration pneumonia. For emergency surgery, this factor is overlooked, but not for elective surgery.

While anesthetic risk is not zero and never will be, the risks are low and shouldn’t prevent any pet owner from providing health care for their pet whether it’s a dental cleaning or major surgery.