Cats can lose hair on the back of their legs when they have an illness or a condition such as congenital hypotrichosis, eosinophilic granuloma, feline endocrine alopecia, hyperthyroidism, hypothyroidism or are simply under a large amount of stress and anxiety according to WebMD. There are other conditions that can cause cats to lose hair, though usually not on the back legs, such as cortisone excess, demodectic mange, indolent ulcers, psychogenic alopecia, ringworm and stud tail, reports WebMD.
If a cat is experiencing hair loss, something is wrong regardless of whether the problem is simply too much stress and anxiety or a hormone imbalance causing a more problematic condition or illness. If a cat has hair loss on its back legs, it should be brought into a veterinarian's office so that it can be examined, diagnosed and treated reports Purina.
Veterinarians will first give the cat experiencing hair loss on its legs, a thorough examination that will most likely include hair samples, blood tests and even skin scrapings. These tests will make it easier for the veterinarian to draw a conclusion and to provide a diagnosis. The vet will also look for fleas and parasitic infestations, as well as hormone levels. The vet will also ask owners if the cat has been demonstrating behavioral problems at home that may indicate that something in the home is stressing the cat and causing it to over groom the leg area, reports Purina.