Today on Texas Vet News I am going to talk about a fairly common problem seen in a horse's ears called aural plaques. These aural plaques are painful, raised small lesions on the inside of the horse's ear that may not even cause a problem but many times can cause horses to be ear shy due to the pain. They are caused by a virus. These lesions cause even more problems in spring due to the flies as flies irritate the plaques increasing the pain and are also suspected to aid in transmitting the virus to other horses. Small tumors in the ears can appear similar to aural plaques so in some cases a biopsy may be needed to diagnose the problem.
Many treatments of the condition have been used including applying a human product on the lesions called Retin-A. Since it is caused by a virus, immune stimulants such as interferon have been used as well as topical antibiotics, cortisone, and fly repellants. One of the newest treatments used is Aldara cream. Aldara can be obtained at a human pharmacy with a prescription from your veterinarian. The cream should be applied in a light layer to the plaques in the ear two to three times per week. Prior to applying the cream, it is important to clean the ear and be aware these horses are feeling pain and most will require sedation by your veterinarian. The Aldara cream causes an inflammatory reaction and the ear may even get more painful the first week and then the pain will decrease. Treatment is recommended for at least 2 months. Aldara cream has also been used on sarcoids, which is a common skin tumor. Although Aldara cream is fairly expensive, it seems to be effective in these difficult to treat conditions.