Health and Husbandry of Mice

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.