Why are the undersides of my rex rabbit's hind legs becoming very bare on their undersides?

Rexes are very vulnerable to this particular problem as they have just a thin covering of fur on this part of their body. The underlying cause for the localised loss of fur here is likely to be that your pet does not have enough bedding.

The result will be that the fur will directly rub on the wood forming the floor of the hutch. The soft hairs become worn away easily as the rabbit moves around, hopping on this part of its hind legs which are in constant contact with the ground.

The situation can be worsened if the bedding is damp, and particularly if the conditions are unhygenic. A lack of bedding is then likely to lead to urine scalding on the underside of the hind legs of rex rabbits in this situation. This is often particularly serious, because with the skin being affected, there is a serious risk that it will lead to a potentially serious infection here, and may even trigger a more generalised illness.

Aside from improving the depth of bedding therefore, do check on the underside of your rabbit's legs, and if you see any signs of skin inflammation, seek veterinary advice without delay. The fur should regrow in due course, once the housing conditions for your pet are improved. Beware outside in a run, because muddy surroundings can have this effect too.