Dermatitis may be cause of cat's strange color

7/14/2007

Dear Dr. Thompson: Over the past few years, my white, inside-only, 14-year-old male cat has developed a brown, sandy residue on his belly, legs, and paws. It has gotten increasingly worse. Originally it started just on his belly and now has spread to the other areas, but has not started on his face, sides, or back. When I bathe him it washes off, but returns full force with just a few days. Kitty seems healthy, but it does not look good, and his face is always "dirty" and discolored from washing himself. Any suggestions?

ANSWER: The discoloration may be resulting from a couple of issues. Skin has normal oil glands that are continually producing a protective secretion. In some animals these glands overproduce, resulting in an oily skin and coat. This oil then can become a breeding ground for bacteria and attract dirt and debris. The fact that it washes off is suggestive of a seborrheic dermatitis.

However, a number of allergic skin problems can lead to seborrhea, or excessive oil secretion. Food, environmental, and flea allergies all need to be considered. Some unusual parasitic skin diseases can also create a scenario similar to yours. Some tests may be needed to help differentiate the source of this trouble. Effective treatment for seborrheic dermatitis requires an accurate diagnosis.

Once your veterinarian has eliminated any underlying conditions, the goal is to minimize the impact of the oils on the skin. Bathing with special shampoos that are designed for oily skin conditions will help. The most difficult aspect of that course of treatment involves that act of bathing your cat. Some cats can be trained to tolerate bathing, but many turn into Tasmanian devils whenthey hit the tub, so be very careful. Some beneficial fatty acids can help decrease inflammation in the skin, and frequently antibiotics are needed to clear any secondary superficial infections. Skin conditions can be difficult to diagnose and treat, and often it is trial by elimination. Your veterinarian may suggest referral to a veterinary dermatologist if the condition is not improving.

Dear Dr. Thompson: My 3-year-old dog has been limping off and on for a few months. A couple of days ago after playing with the neighbor dog, he wouldn't use one of his front legs. My veterinarian took X-rays and said he has elbow dysplasia. I have heard of hip dysplasia, but not in the elbows. How often is this seen, and what are my treatment choices?

ANSWER: Elbow dysplasia is a common developmental orthopedic problem that affects significant numbers of dogs. It is a general description of abnormalities of the elbow joint. Two of the main bones involved are the radius and ulna of the forearm. These bones have a tough, fibrous connection, and if one grows at a different rate, the other will be dragged along. This then results in a poor fit of the bones of the joint. These will bang together and arthritis develops as the dog ages. Small bones inside the joint called the coronoid and anconeal processes can break off, dramatically increasing the pain associated with the disease.

A thorough exam by your veterinarian, along with X-rays, will help in diagnosing elbow dysplasia. If the problem is from abnormal growth of the bones of the forearm, surgery can help improve function. However, early intervention is necessary. Once your dog is skeletally mature, the success decreases. Surgical removal of any bone chips inside the joint is indicated if the use of the leg is dramatically reduced. Arthroscopic surgery in dogs is available but would require a trip to a specialist. This option is less invasive and the return to normal function is much quicker.

Otherwise, traditional surgical removal would be needed. If your dog does not require surgery, traditional therapies for arthritis will improve function and comfort. One of the mainstays is effective weight control. These animals will have trouble with high-impact exercise and weight gain can result. Low-impact walking and swimming are great options for these dogs.

Like hip dysplasia, there is a strong genetic component, and poor breeding have made this disease more common than it should be. Some responsible breeders are screening their dogs for elbow and hip dysplasia, but this is the exception rather than the rule. Hopefully, your dog will recover and be back to regular exercise in no time.

Questions for Dr. Thompson can be e-mailed to askthevet@theblade.com or mailed to The Blade, Attn. Ask the Vet, 541 North Superior St., Toledo, OH 43660. Dr. Thompson regrets that he cannot answer individual letters.