Siamese mice: markings and everyday care

What is a Siamese mouse?

A Siamese mouse is a pet mouse with a pointed pattern: a pale body and darker "points" on the coolest parts of the body. It is the same species as every other fancy mouse, so it isn't a breed of its own. The pattern can turn up with any coat type, from standard smooth coats to satin, long-haired and rex (curly) coats. Our pet mouse breeds and colours guide covers the other varieties.

The American Fancy Rat and Mouse Association (AFRMA) describes the seal point Siamese as a warm beige body, as even as possible, shading deeper over the hindquarters, with rich chocolate points on the muzzle, ears, feet and tail. White on the feet or tail counts against a show Siamese, which is why breeders select for colour right down to the toes and tail tip.

Siamese mouse colours: seal point, blue point and more

Seal point is the classic Siamese mouse, and the one most often meant by "Siamese mouse". Several related colours use the same pointed pattern.

The descriptions above are from AFRMA's show standards. The UK's National Mouse Club shows Siamese in its "any other variety" section; its bluepoint standard asks for a silvery blue body, gradual shading darkest at the tail root, and points that blend into the body with no hard line.

AFRMA's side-by-side photos show that at 11 days old, seal and chocolate point littermates are hard to tell apart. By seven weeks the difference is clear. Pet shop mice are rarely bred to a standard, so many "Siamese" pet mice are somewhere between these descriptions, which is perfectly fine for a pet.

Why Siamese mice change colour

The colour is temperature sensitive. AFRMA explains that the fur's colour depends on the temperature of the skin where it grows: the cooler extremities, the nose, ears, feet and tail, grow darker fur, while the warm body grows paler fur. This is called acromelanism, and it is the same reason Siamese cats and Himalayan rabbits have dark points.

• Babies are a light, creamy beige with almost no points
• Points appear after the first moult of the baby coat, usually pale at first
• Points get darker with each moult until adulthood
• Fur that grows during cooler months tends to come in darker

The genetics are simple. AFRMA gives the Siamese as two copies of the Himalayan gene (ch ch). A Himalayan mouse has one Himalayan gene and one albino gene, which lightens the body to almost white. A Siamese bred to a pink-eyed white mouse gives all Himalayan babies, and two Himalayans bred together give roughly a quarter Siamese, half Himalayan and a quarter pink-eyed white. We don't recommend breeding pet mice: rescues already have many mice needing homes.

Caring for a Siamese mouse

Colour makes no difference to care, temperament or health. A Siamese mouse needs everything any pet mouse needs.

1. Sort the company. Female mice are social and should live in pairs or groups. Male mice often fight and may need to live alone, or be neutered and housed with females. Our guide to male or female mice explains the options.
2. Get a big enough cage. Choose a secure, escape-proof home with narrow bar spacing or a tank with a mesh lid, as large as you can fit. Our pet mouse cage size guide gives the numbers.
3. Add bedding and nesting. The RSPCA suggests at least 2 cm (about 1 in) of dust-free bedding (substrate) such as cellulose or paper, and nesting material like hay or shredded paper. Avoid fine sawdust, fragrant or coloured bedding and fluffy cotton-wool nesting.
4. Fill it with things to do. Add hides with more than one exit, cardboard tubes, ropes, branches and a solid, axle-free wheel. The RSPCA notes a wheel shouldn't be the only enrichment.
5. Choose a quiet, steady spot. Keep the cage out of direct sun, away from radiators, draughts, kitchens, bathrooms, conservatories and garages, and away from loud appliances.
6. Feed a proper mouse diet. A good mouse pellet or block as the base, a little fresh vegetable and the occasional treat. Our pet mouse diet guide has portions.

Pale mice show staining from urine more easily, so a Siamese with a yellowed belly or tail base may just need a cleaner cage or more bedding. Hair loss, scabs, a hunched posture, weight loss or sneezing need a vet check. Our pet mouse health guide lists the signs.

Where to get a Siamese mouse

Siamese and Himalayan mice turn up in rescues and in pet shops, and specialist breeders who show mice often have well-pointed lines. If you go to a breeder, ask how long their mice usually live, how they handle the babies and whether the parents have had any health problems. Our guide to where to get a pet mouse covers rescues first, then breeders, and what a healthy mouse looks like.

Our guide to taming a pet mouse shows how to build trust. Need a name to go with those dark points? Our pet mouse names list has plenty, and our complete pet mouse care guide covers everything from cleaning to handling.