Editing Fancy rat (section)

==== Hairless rats ====
[[File:Hairless rat Lhassa.jpg|thumb|Even though this rat is hairless, [[pigmentation]] indicates that it is a hooded rat.|alt=|left]]

{{See also|Laboratory rat#Hairless rat|l1=Hairless laboratory rats}}

Hairless rats are a coat variety characterized by varying levels of hair loss. One type of hairless rat is bred from curly-coated rexes. These range from having areas of very short fur to being completely bald. Since rex is a [[dominant trait]], there only needs to be one rex parent to produce curly rex-coated offspring. However, when two rex parents are bred, two copies of the trait may be present in the offspring. This causes varying levels of hairlessness, and has earned the colloquial name "double rex". The other type of hairless rat is sometimes referred to as a "true hairless". This is caused by a different gene, and is distinguishable from a hairless double rex by the absence of whiskers. Unlike a double rex, this type of hairless rat is incapable of growing hairs on any part of the body. One additional subset of semi-hairless rats, patchwork rex, constantly lose their hair and regrow it in different "patches" several times throughout their life.<ref name=afrma-std /><ref name=nfrs-std /> Hairless rats may be prone to more health problems than their standard- or rex-coated counterparts, including a reduced tolerance for cold, kidney and liver failure, more prone to skin injury, skin conditions, and shortened life span.{{Citation needed|date=March 2024}}{{Citation needed|reason=Reliable source needed for last sentence.|date=June 2019}}