American Fancy Rat & Mouse Association

This article is from the May/June 1996 AFRMA Rat & Mouse Tales news-magazine.

The Siamese Rat

By Nichole Royer

The History

In the U.K.—In 1978 the National Fancy Rat Society was offered the opportunity to acquire Siamese rats. Their genetical advisor, Mr. Roy Robinson, offered to assist in importing the rats which were then located in a laboratory in Orly, France. A laboratory in Charshalton, Surrey, offered to cooperate in this venture sharing the expenses entailed in quarantining the animals. Three pairs were imported and kept by the laboratory, and the first litter from each pair went to the NFRS. In order to cover the costs of this venture, the NFRS sold £5 shares which entitled their holders to one of the offspring.

The animals arrived at the laboratory in September 1978 and their offspring were delivered to the NFRS just before Christmas. Apparently these kittens looked nothing like what we recognize as Siamese today. Instead they resembled Silver Fawn Hoodeds with very faint dark noses. Fortunately, through hard work and sensible breeding practices, English Fanciers were able to take these original animals and turn them into the beautiful rats we have today. (For the complete “History of the Siamese Rat in the U.K.,” please see the March/April 1987 issue of AFRMA Rat and Mouse Tales.)

Siamese Rat
Sumi, AFRMA’s first Best In Show Siamese. Owned by Mary Macdonald.

In the U.S.—In November of 1983 a few Southern California fanciers cooperatively imported a number of rats from England. These included Pearl, Cinnamon Pearl, Variegated, Chocolate, Silver Fawn, Cinnamon Rex, Black Berkshire, Black Rex, and Self Black, as well as four pairs of Siamese/Himalayan. To my knowledge, all of our Siamese are descended from these 8 rats plus a few others that were imported at various times by individuals. (Other organizations or individuals not known to me may have imported Siamese from the U.K.)

Siamese rats first made their appearance at an AFRMA show on March 31, 1984. Seven were entered with Samantha, owned by Mike Nez, winning Best Siamese. At the very next show, May 19, 1984, a Siamese named Sumi won Best In Show. She was owned by Mary Macdonald.

The Siamese Color

The Siamese pattern has a somewhat unusual cause. Called acromelanism, this pattern develops because it is thermo-sensitive (the darkness of the fur color is determined by the temperature of its environment). The colder it is, the darker the fur comes in. This is why those areas on the rat which are cooler (nose, ears, feet, tail) have darker fur than the body which is warm. It is also why Siamese rats are darker in the winter than they are in the summer.

The AFRMA standard describes them as “Body color to be medium beige gradually and evenly shaded over saddle and hindquarters towards the belly, being darkest at base of tail. Tail color to extend down the length of the tail. Belly to be light beige. Points to be rich dark sepia and to shade evenly into the body color. Eyes red or light ruby. (English)” Disqualifications are white spot on the body, white feet, and white on the tail. Essentially, these animals should be an even cream color with rich brown points, and lots of shading. The color should continue up the rear of the rat, gradually fading out at about midway along the back.

Breeding The Siamese

Siamese is recessive. Two Siamese bred together will produce all Siamese babies. Siamese bred to Black will produce all Black babies. If two of these Black babies are bred together, the resulting litter will be three-fourths Black and one-fourth Siamese. This is the recommended outcross for improving Siamese.

The same thing will happen if you breed to Agouti. The first generation will be all Agouti; then, if two littermates are bred together, their litter should be three-fourths Agouti and one-fourth Siamese. Using Agouti for an outcross is not recommended as it makes the points mealy and ruins the color on the Siamese.

If you breed a Siamese to an Albino, your resulting litter will be all Himalayans. Two Himalayans bred together will make one-fourth Siamese, one-half Himalayan, and one-fourth Albino. If you are making Himalayans, it is important to use an Albino which is out of a background of good Blacks with dark feet.

Tailless Rat
One of the earliest Tailless appeared in Karen Robbins’s first litter of Siamese after their import.

When breeding Siamese, there are three main points to look for: white feet, darkness of points, and shading. White feet are the number one problem in Siamese rats. They can range from the entire hand being white to the wrist, to half the hand being white, to just some white on the toes. Any white on the feet is BAD. Ideally the color should run down the toes and into the nails; however, the feet are rarely dark enough to show it. Use Siamese who have white toes with caution; and if you have any choice, do not use them at all. If you must breed a Siamese to a rat with white markings, do so with the understanding that it will take a number of generations to get rid of the white feet. The best way to eliminate white from the feet is to outcross to a really good Self Black which has pigment all the way down to its toenails.

A good Black is also an excellent choice for darkening the points and improving the shading, though simple selection also works well. Breeding those animals with the darkest points and shading (and good foot color) together will often produce some really nice animals. Unfortunately, shading does not become obvious until the animal is around 6 months old, and is much more prominent on males than females. This makes early selection difficult and is further complicated by the fact that both color and shading are determined by the surrounding temperature.

Siamese kittens are born an even creamy-brown color—the best are colored brown all over, the poorer ones having light shoulders with dark heads and rears. They do not begin to develop points until their first moult, which can make it very difficult to choose the best ones to keep. Any with white feet/toes or tail tips should be sold to pet homes. From the rest, keep the ones that appear darkest at 5 weeks and have the best foot color. These will usually (though not always) have the best points and shading. Bear in mind that even the potentially darkest kittens will appear washed out if they are born during the summer.

Variations Of Siamese

When Siamese is bred to Albino, the resulting litter will be all Himalayans. These animals are in theory pure white with dark points. In reality they are usually light cream colored with rather light points. Unfortunately, no one (that I know of) in Southern California is specifically working on these, and what are usually shown as Himalayan, is in truth just very light Siamese.

Blue Point Siamese have recently been standardized by AFRMA. They are very light in color, with ivory bodies and pale gray points. Often described as pastel, they resemble Lilac Point Siamese cats. Russian Blue Point Siamese are the most recent variation to be created and have yet to be standardized. They are much darker than Blue Point Siamese rats, and closely resemble Blue Point Siamese cats.

It is unfortunate, but it is apparently impossible to produce Flame Point Siamese rats. According to those who have tried, when Siamese is combined with Fawn, the points are so diluted that the animals appear to be Pink-Eyed Whites.

Showing The Siamese

Siamese rats are fairly popular and rather flashy, so when you have a good one, it usually does well on the show bench. Unfortunately, there have not been many good ones around in recent years. Some breeders however, have been working hard on them, and there are a few really nice ones beginning to appear.

Siamese Rat
A very nice Siamese male owned by Karen Robbins. (Note the shading on his back.)

Males are the better choice for show animals, as females rarely develop much shading. There should be a considerable amount of color running up the back side of a Siamese, and they should not have just a little bit of brown at the base of their tail. (For a picture of a Siamese rat with really nice shading, look in the book The Proper Care Of Fancy Rats by Nick Mays. We don’t have anything that nice in this country!) Remember, all Siamese will fade during hot weather so they show better in the winter months.

No show Siamese should have white on its feet; however, light toes are permissible (dark is always preferable) particularly during the summer when the color has faded.

Preparations for a show should start several weeks ahead of time. Since the color of the Siamese is affected by temperature, it is advisable to keep them cool for some time before a show. During the summer they can be brought into an air-conditioned area, and during the winter they can be moved to a cooler cage setup. Some people have even put their rats in the refrigerator for short periods of time every day for several weeks to darken the color. (Please use common sense in trying to darken the color. Rats can get sick if they are kept at too cool a temperature.)

Being light colored, it is often necessary to bathe a Siamese prior to a show. Make sure to do so a week ahead of time however, so that the coat regains its natural oils.

Though challenging, Siamese rats can be very enjoyable and rewarding to work with. Like all other varieties, a Siamese must have good conformation and condition as well as color to do well at shows. This combination is not available at pet stores, and it is recommended that a novice fancier go to an experienced breeder to buy stock, rather than starting with the pet shop variety and trying to improve it.

A Sad Note In The History Of The Siamese

When Siamese rats were first imported into the U.S., they were regarded as unusual and rare, and to pet shops this meant they were worth a lot of money. Some people acquired a Siamese or two, and bred them to anything and everything they had, with no consideration given to type, temperament, color, or health. Not only was the Siamese color ruined, but they developed major health problems and there were many cases of them being extremely aggressive. It was not all that long ago (1991) that I purchased a very nice young Siamese for a pet from a pet shop who turned out to be so aggressive that I couldn’t even touch him. Eventually Siamese rats developed a reputation for being mean, and many pet shops stopped buying them. To this day you can often find rather odd Siamese being sold as feeders in pet shops (Hooded Siamese and ones with Blazes are fairly common). Siamese are very easy to ruin, and take years to fix, so it is fortunate there are dedicated breeders who have been working on improving this variety. Needless to say, I highly advise purchasing from a breeder rather than from a pet shop. *

Go to History Of The Siamese Rat In The U.K.
Breeding Blue Point Siamese Rats

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Updated June 30, 2018