As one of only two varieties banned at NFRS shows, the hairless rat is often thought of as a rare or unusual rat, and sadly often churned out in great numbers by less-than-ethical breeders hoping to cash in on this perceived rarity. In reality, hairless rats are fairly common, but just mainly absent from the mainstream fancy.
Several breeders have attempted over the years to breed healthy and vigorous lines of hairless rats, using hairless from various sources bred into well known and strong furred lines – sadly so far all of these attempts have been abandoned due to health issues, suggesting that the health issues seem are innate to the hairless variety rather than coincidental to the lines that the hairless have come from.
Genetics: Several hairless genes exist in the fancy. The scientifically described hairless genes would give the genotypes fz/fz, hr/hr, n/n, rnu/rnu, or shn/shn. There are most likely others that are not scientifically described, but for simplicity most hairless are just given the genotype hr/hr.
In the UK fancy, at least two recessive hairless genes exist. The most common gives a fuzzy bodied rat with slightly thicker fur over the head, paws, and tail base. Whiskers and eyelashes on this variety are curly, but not overly brittle. This variety can be selectively bred to be more hairless, but tends to be fairly weak health-wise. The majority of hairless in the UK are this fuzzy-hairless type, which was originally nicknamed “velvet” or “velvet fuzz” when it was imported. It can be mistaken for a fairly bald double rex.
The second hairless gene is much rarer, though it appears to be the more common gene in the US. This gives a much more extreme hairless, with either missing or extremely short whiskers and eyelashes and a smooth body with only occasional thin hairs. Not much breeding has been done with this variety in the UK as the hairless does cannot lactate. The missing whiskers and eyelashes also present their own animal welfare issues.
Standard: No official UK standard exists for this variety. A sample standard could read as: To be as hairless as possible with bright, healthy skin, soft to the touch. Some short, soft fuzz is acceptable above the eyes, at the ankles and wrists, along the whiskerbed, and in pubic areas- this fuzz shall not be excessive or detract from the overall hairlessness of the animal. Whiskers, eyelashes, and the vibrasse above the eyes may be curled or bent as in rexed rats but cannot be brittle, very short, or missing. The ears should appear larger then on a classic coated, classic body-typed rat.