male cat stray

Question
losing hair on belly and under legs and on joints

Answer
Hi Todd.  There are a lot of reasons why a cat may lose fur.  The most common reason in outdoor cats may be a flea allergy.  One flea bite can cause itchiness that spreads, causing a cat to scratch and lick until his rough tongue breaks his fur off.  He may even pull out his fur in clumps.  The best way to deal with a flea allergy is to keep the kitty treated with a monthly flea preventative, such as Advantage, Frontline or Revolution, all available through vets.  For Revolution, your kitty would need to be examined prior to having the medication administered, since it is by prescription only.  Frontline and Advantage may be obtained without a prescription through any veterinarian, or through reputable online pet pharmacies like petmeds.com (also at some pet stores).

Cats can also lose fur because of food or environmental allergies, which cause skin itchiness.  Working with a vet to find a low-allergen food that works for your cat may help.  Environmental allergies can be tougher to tackle.  There are also cases when the cat's immune system may be attacking skin cells themselves for some reason.  In this case, it's considered an auto immune disease.  Most of the time, kitties who have hair loss with itchy, broken skin due to allergies or auto immune disease will benefit from a cortisone injection.

There are infectious possibilities, like ringworm, a fungal infection, and mange, caused by microscopic mites.  Both cause intense itching, crusting and scabbing along with hair loss.

Even endocrine disorders like overactive thyroid can cause fur loss!  So the best idea is to have a vet look at the kitty and diagnose the problem officially, so you can get started on the proper treatment right away.