Mice
DOMESTIC MICE
Susan Leck, DVM, Dipl ABVP-canine & feline
Domestic mice, Mus musculus, are primarily raised in captivity for the pet trade and as
food for reptiles. They are available in colours from white and tan to brown and black.
Outbred and inbred mice are used for research purposes.
Pet Appeal and Behaviour
Mice are easy to keep as pets because of their very small size and their minimal
requirements for space and attention. Although naturally timid, a significant bond with
humans may be formed with daily interaction and regular gentle handling.
Mice may bite if they are handled roughly or startled and may become
aggravated when restrained. Mice are territorial: males will initially fight when placed
together, and females with litters may defend their nests. Mice that have been housed
alone are more likely to fight when introduced to other mice.
Housing Recommendations
Mice can thrive in captivity as long as they are not overcrowded or overheated. The
minimal size enclosure for one adult is 24" x 24" x 12" high (61 x 61 x 30 cm). Females
with litters require 2-3 times more space. The enclosure must be able to accommodate
a nesting area, feeding area and exercise wheel. It must be escape proof with a secure
lid. Glass aquariums are not recommended, because they can overheat rapidly on a
warm day and can kill a mouse.
Suitable substrates include shredded paper (non-inked), recycled newspaper
composite materials or pellets. Cedar chips should be avoided, as they may be toxic.
Substrate should be changed once or twice weekly in order to keep the cage as odour
free as possible. Additional materials (e.g., paper towels, socks, mittens) may be added
to the enclosure for nesting.
Diet
The recommended diet for domestic mice is a commercial pelleted mouse feed (greater
than 14% protein, ideally 20-24% protein). Breeding adults and youngsters may require
additional calories. Pellets may be softened for baby mice, which will begin eating them
around 2 weeks of age. Seed diets are not recommended: mice are often victims of
obesity, starvation and malnutrition from all seed diets.
Sipper tubes or water bottles may be used. The water must be changed routinely
and the tip checked to ensure it is flowing and free of obstruction.
Restraint
The mouse may be grasped by the skin at the base of the neck and the base of the tail
for restraint. Grasping the tip of the tail may cause degloving. A mouse may be
accustomed to climbing onto hands, but one must ensure that it does not jump and fall
off.
Common Disorders of Domestic Mice
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Obesity
Ectoparasitism
Epizootic diarrhea of infant mice
Alopecia
Barbering
Chronic respiratory disease
Pinworms
Neoplasia
Malocclusion
Heat stress
Viral infections
Malnutrition
Trauma, bite wounds
Toxicities/poisoning
Giardiasis
Salmonellosis
Mouse pox
What Every Owner Should Know
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A child should not be responsible for the feeding and care of a pet mouse.
Small children may handle the mouse too roughly or drop it, resulting in trauma.
Common household dangers include predators, such as dogs, cats, and ferrets.
Mice can be escape artists, so the enclosure must be secure.
For activity, mice like to explore tubes, gnaw on items and run in an exercise
wheel.
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 Mice should be prevented from accessing pesticides and other toxins.
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 They should be protected from overheating.