Dr. Dan Christian specializes in small animal medicine, with special interests in behavior and nutrition. He has been instrumental in establishing animal behavior residencies for veterinarians at leading veterinary schools and developing innovative programs with veterinary organizations in the United States. He is a member of the American Veterinary Medical Association, the American Animal Hospital Association, and the Southern California Veterinary Medical Association. During his professional career, Dr. Christian earned the American Association of Feline Practitioners Award. He has also appeared as a guest on television and radio pet health programs nationwide, and to has authored numerous articles for pet health magazines.

Q: My cat has trouble with his ears. There is a dark brown or black sticky substance in his ears. He lets me clean them, but it keeps coming back. The vet has given me antibiotics for it, but it still keeps coming back. There is no odor, but it bothers him a lot. Do you have any solutions to the problem?

A: When a cat has ear problems, it is usually caused by either ear mites or an infection (or both). A cat with these problems will scratch at his ears or shake his head. The condition is extremely irritating and uncomfortable for cats, and may lead to more serious internal ear problems, if left untreated.

Ear mites are very tiny, barely detectable with the naked eye. Often, the veterinarian needs to look at them through an ear instrument called an otoscope, or to look at a swab of ear debris under the microscope to find them. If mites are found, medications must be used to get rid of them. However, if your cat spends time outdoors or around other cats who may have mites, the mites will reappear. So be sure to constantly check his ears for the appearance of black, waxy debris.

Infections are usually more moist in appearance, and can be appropriately treated with antibiotics. There are times when several different antibiotics may need to be used to combat the infection effectively.

If the irritation is still proving troublesome, your veterinarian may need to test for fungal infections. While slightly less common, they can prove frustrating to treat.

In any event, make sure your veterinarian is aware that the condition persists so he or she can perform additional tests to find out what the problem is and effectively treat your cat.