Mus Musculus Domesticus

Fancy mouse (Mus Musculus Domesticus)

A tame black fancy mouse
Fancy mice ("fancy", in this context, means "hobby") are domesticated breeds of the common or house mouse (Mus musculus). The terms fancy and "feeder mice" are often used interchangeably by retailers, and are in fact the same variety of mouse.

Physical description

Fancy mice is a term to describe mice that have been selectively bred for exhibition. They can vary greatly in size, from small pet mice that are approximately 15–17.5 cm (6–7 in) long from nose to the tip of the tail, to show mice that measure 30 cm (12 in) nose to tail. Pet mice weigh about 29–44 g (1.0–1.6 oz) but large show mice can weigh up to 130 g (4.6 oz).
Human-directed artificial selection in fancy mice has created a variety of colors and patterns. These include black, chocolate, blue, white, cream, lilac, red, fawn, champagne, cinnamon, golden agouti, silver agouti, silver and dove. Standards are slightly different under the separate clubs.

Mice as pets

Fancy mice are in a wide variety of colors not found in nature, such as this Even-Broken Agouti.
 
The first written reference to mice kept as pets occurs in the Erya, the oldest extant Chinese dictionary, from a mention in an 1100 B.C. version.In Europe the breeding of fancy mice became popular through the introduction of Japanese stock in the early 17th century. By 1895 Walter Maxey founded the National Mouse Club in Victorian England, with its first official show held in Lincoln that year. Since that time, mouse clubs have formed worldwide. Shows are held so competitive breeders can display their mice, where they are judged on color and behavior.
Mice are kept as pets in many countries for a number of reasons: Fancy mice are relatively small, inexpensive, never need bathing, and can learn to enjoy regular handling.Female mice are popular with many owners since they tend to cohabitate with other mice better than males. Additionally, the urine of female fancy mice does not contain as strong an odor as that of the male mice. Bucks usually fight with and kill each other when housed together, even if they are brothers, and are introduced at a very young age, due to their very strong and unchangeable territorial instincts.It is difficult to house male mice together without the risk of injury to one or both males.Some people, however, prefer the personality and curiosity of male mice.It is a good idea to keep fancy mice in groups of at least two if possible, as mice are sociable animals. However, if a buck and a doe of breeding age are put in the same cage it is possible for them to reproduce at a maximum frequency of once every three weeks.

Mice in Shows

There are several clubs all over the world who host shows for mice, similar to rat shows. Shows are held in the US, the UK, and Australia most commonly. Clubs include AFRMA (American Fancy Rat and Mouse Association, US), ECMA (East Coast Mouse Association, US), RMCC (Rat and Mouse Club of china, US), NMC (National Mouse Club, UK), and more.
A quote from the NMC, describes the ideal mouse body type, for showing: "The mouse must be long on body with long clean head, not too fine or pointed at the nose, the eyes should be large, bold and prominent. The ears large and tulip shaped, free from creases, carried erect with plenty of width between them. The body should be long and slim, a trifle arched over the loin and racy in appearance; the tail, which must be free from kinks should come well out of the back and be thick at the root or set-on, gradually tapering like a whip lash to a fine end, the length being about equal to that of the mouse's body. Unless the variety standard states otherwise, the coat should be short perfectly smooth, glossy and sleek to the hand. The mouse should be perfectly tractable and free from any vice and not subject to fits or other similar ailments. A mouse with absence of whiskers, blind in one or both eyes, carrying external parasites, having a tumour, sore or legs with fur missing, suffering from any obvious disease or deformity or kinked tail shall be disqualified."

Caging

Mice enjoy group housing and require nesting areas such as this wooden hide.
 
Glass aquariums or cages with wire bars and plastic flooring, are the most common types of housing. A span between cage bars of less than 9 mm (0.35 in) prevents young mice from attempting to escape by forcing themselves through the bars, where they may get stuck. This can also help prevent predatory pets such as cats, dogs, arthropods, snakes, and other carnivores from killing and eating the mice.
Mice are naturally cautious of rats, who may kill and consume them. This rat behavior is known as muricide (Tattersall, Smith and Nowell 1997). The mouse cage should be cleaned every couple of days to stop it smelling and disinfected properly every 2 weeks to prevent infection and disease. In the wild, mice are able to co-exist with other small rodent species (Moro and Morris 2000). Compared to larger mammals, the mouse's small body makes it difficult to regulate body temperature effectively.Thus, drafts and large fluctuations in temperature can adversely affect the health of mice.
The best products for in cage bedding are aspenwood shavings. Paper-pulp-based products are also available, as well as a variety of recycled products, though newspaper products may contain inks, dyes and other chemicals from the papermaking process, but all are non-toxic. Cedar and pine, even kiln-dried, should not be used as they release aromatic oils that damage the respiratory system and can cause or exacerbate chronic respiratory disease.Recent research suggests that paper-pulp beddings may allow very high concentrations of ammonia to build up in cages, especially those with little ventilation. (Vanderlip 2001, ISBN 978-0-7641-1812-8). Small hideaways and toys (such as a cardboard tube) are good to have in the cage. Commercial toys are also available.Mice love to run on a wheel, which provides stimulation as well as exercise.

Feeding

Hand-feeding 10-day old mice
 
Food for fancy mice can range from specially-formulated feed mix to kitchen scraps. Carrot, spinach, tomato, and lettuce are usually very inexpensive, although the latter should be applied sparingly as it may not provide a balanced diet. Bread crumbs, wheat and rice can also be good for mice. Laboratories keeping mice as experimental subjects almost uniformly use a product called lab block, a scientifically-formulated blend originally designed for mice in laboratories. In order to keep variety in their diets, mice can also eat oats, oily seeds, clean eggshell, breakfast cereal, and stale bread. Fruit and vegetables are part of a more natural and healthful diet. Some owners give it to them as a treat after they do a trick. Mice often chew wood and other hard substances which keeps their teeth from growing too long; salt licks are also an option.[citation needed] As mice and rats have similar diets, some pet mouse owners choose to feed rat food. Although it is common practice to feed premixed diets designed for other rodents, for the longevity and health of the animal it is best to feed mouse-targeted diets. Diets for hamsters, for instance, are known to contain higher protein than what is required for mice or rats. Homemade diets can be blended using grains, rice, oats, seeds (such as peanut, sunflower, and pumpkin), high quality dog food, as well as a number of other ingredients.
House mice primarily feed on plant matter, but they will also accept meat and dairy products. Meats are full of protein and are great for pregnant or nursing mice. They will drink water but require little of it, relying mainly on the moisture present in their food. If a water source is provided, then a gravity bottle feeder is necessary for maintaining the cleanliness of the water supply. They will eat their feces to acquire nutrients produced by bacteria in their intestines in a behavior they share with rabbits and guinea pigs called Coprophagy. House mice, like other rodents, do not vomit.

Health

A healthy fancy mouse will live on average 18 to 30 months, depending on genetic predisposition. Like most mammals mice are susceptible to mites, ticks and other skin parasites, as well as intestinal parasites. The cage should be cleaned regularly, and preferably treated with anti-mite spray. Mice are particularly sensitive to drafts and may pick up colds and other flu-like conditions. Mice can also over-groom when stressed, leading to skin irritations and fur loss. Older mice are susceptible to tumors, especially breast cancer in females as the mammary tissue is distributed around much of the body. Persistent problems should be referred to a veterinarian, although finding a vet with experience in treating mice can be difficult.
Like people, fancy mice can become obese if they overeat and do not get enough physical activity. This can lead to them developing life-threatening cardiovascular disorders and diabetes as well as arthritis. Unfortunately overfeeding is common as they require little food. Activity aids such as tubes and wheels are great for ensuring mice get enough exercise, as well as mental stimulation. Mice also love to climb, and a wire cage with horizontal bars is perfect for this. A mouse set loose for exercise should be carefully observed, as they tend to scurry into a hiding spot and can be difficult to retrieve.
As rodents, mice must gnaw to keep their incisors from growing too long. Overgrown teeth can cause occlusion (blockage) of the mouth, which in extreme cases can lead to starvation. Hard foodstuffs, small pieces of wood or specially-prepared blocks can suit this purpose, although some mice can grind their teeth together ("bruxing") to keep them short. In rare cases a mouse may not be able to gnaw effectively, either from malformed incisors or jaws, and so its teeth must be trimmed by a vet.
Mice self-groom and do not need to be bathed, unless they have a skin condition which requires special treatment.
Also, like people, mice can get diarrhea. For humans in developed countries with access to clean water, this is usually not a life-threatening. For mice though, it can be. Once a mouse gets diarrhea, since it is so small, it can very easily lose too much liquid, dehydrate, and die.

Handling

It is not natural for a mouse to allow itself to be handled by a human. However with time or training, a mouse may acclimate itself to accept human handling. One way you can train a mouse to get into your hand, is by lowering your hand into their cage, and placing food on the tips of your fingers. When they get more comfortable, place the food further back on your hand so they must walk in to get it. After a while, your mouse thinks of your hand as a safe place, and will easily climb into it whether there is food on it or not. The best way to pick up a mouse, if it won't walk into your hand, is by gently scooping up the mouse with the palm of the hand facing up, and if necessary, cupping both hands around the mouse. Never attempt to pick up a mouse by their tail- doing so can pull the tail completely off, skin the tail, or break the mouse's spine, not to mention the experience being painful for the mouse whether injury occurs or not, and will certainly not endear the mouse to you, making the taming and handling process even tougher. Pet stores frequently pick up their mice by the tails, and will most likely tell you that it is acceptable, but it is simply easiest, not at all the best way. Retrieving a skittish mouse from its cage can be frustrating; they frighten easily and often try to hide. One method of retrieval is to coax the mouse into a cardboard tube placed in the cage, then pick up the tube.
Although mice are small animals and care must be taken to avoid injury, they are also surprisingly robust and inquisitive. Once out of the cage many enjoy running along their owners' arms, investigating pockets, or just sitting on the owner's lap and grooming. Some mice also tolerate gentle petting. Care must be taken as mice have poor eyesight and may try to lean too far over an edge and fall. Care must especially be taken when being handled by small children as they may be overly rough. Fancy mice very rarely bite, except when they are hurt or very frightened, and is usually the fault of the human handling them, as mice are not aggressive. (Excluding males who are wild and territorial.)
Unfortunately mice cannot be house trained and will often defecate and urinate while first being handled, especially if they are nervous. The feces of a healthy mouse consists of a relatively innocuous solid pellet a few millimeters long. However their urine is quite pungent, particularly with males, and may stain fabric.

Breeding

A female fancy mouse with her litter
 
Mice have a rapid reproduction rate; the gestation period is approximately 19 to 23 days. The typical litter size is 4 to 12 young. In some instances, up to thirty young have been born. Males can mate with the female as soon as the litter is born, which means that a female could become pregnant with another litter while still nursing her first, which results in less milk to go around and smaller, weaker pups. Female mice should not be bred before 12 weeks or after 8 months; doing so can be very dangerous, and some mice can die while giving birth. Females come into heat around every three to five days, so the pair can be kept together for up to ten days. Baby mice, called pinkies or pups, are born blind, naked, and deaf. Their eyes are closed and their ears are stuck to the sides of their heads. Mothers may eat any dead or sickly offspring. Pups begin to grow hair at two to four days. Ears open at three to five days, and the pups will start vocalizing. Eyes open at 14 days, and the babies will start exploring the world around them. At three weeks old they look like miniature versions of adult mice. At four weeks the males in the litter should be separated out so as to not cause the mother and sisters to become pregnant, the females can be left in with the mother.