Dear Dr. M:
My cat is losing fur, and her belly is bare. She's an indoor cat, her behavior is fine, it doesn't seem to be coming out anywhere else, just her underside.
Could it be the food? The cat litter? I'm at a loss, I would appreciate any information you can give me.
Cats are extremely sensitive to any changes in their environment: i.e. food, litter, house guests, new pets, new furnishings etc. They may experience anxiety due to these changes. Anxiety may further be evidenced by self-mutilation, obsessive
grooming (barbering) or repetitive behaviors.
If you have ruled out any changes in her environment, you might consider some physiologic conditions. Some cats suffer from allergies, either seasonal or environmental. These allergies may sometimes stimulate excessive grooming and cause focal hair loss. These are usually easily managed after establishing the identity of the allergen, although this usually requires a referral to a dermatologist.
Another possibility lies in hypersensitivity to external parasites. Both fleas and mange mites are capable causing rapid hair loss. Parasitism usually has other symptoms though and usually does not affect just one area of the body. Still you should consult your veterinarian to completely rule out parasites.
Some sub-clinical urinary and kidney infections may cause low grade "dull" pain to the abdominal area and cause the cat to "worry" about the area with excessive grooming. Your veterinarian should be able to easily rule out these conditions with laboratory tests. If there is evidence of disease, often the behavior ceases when therapy is instituted.
Finally, the possibility exists that this is a behavioral problem (although you see no other indications of aberrant behavior)
called Psychogenic Alopecia. Most times it is impossible to establish with absolute certainty the impetus for the behavior, but we have found certain medications very helpful in suppressing symptoms. Your veterinarian should be able to discuss these with you, or you may wish to be referred to a specialist in these cases.
Best of luck,
Dr. M.C. Lane