Dermatophyte Treatment in Dogs

Ringworm is a skin problem caused by fungi. These fungi, called dermatophytes, are zoonotic. They spread the contagious infection between animals and humans. When your dog is infected with dermatophytes, he carries the fungi even if he shows no signs of dermatophytosis or skin infection. Treatment is important for the dog̵7;s comfort and to stop the infection from spreading to other pets and people.

  1. Features

    • Dermatophytes primarily affect puppies and sick or aging dogs. Healthy adult dogs have strong immune systems more resistant to skin infections. Symptoms typically include alopecia or hair loss with spots of scaly, crusty skin. The dog itches and has hair loss in one small area or, in severe cases, over the entire body. Because ringworm resembles many other diseases, a veterinarian conducts tests ranging from ultraviolet light inspection to blood tests and lab cultures to identify the fungi.

    Topical Treatment

    • Topical treatment, applied to the dog̵7;s hair and skin, is the primary treatment for dermatophytes. Ointments are rarely effective as the dog licks or rubs off the ointment. Anti-fungal shampoos are lathered into the skin, left on for several minutes, and then rinsed off. Because the fungus lives in hair follicles, long-haired dogs may be trimmed, or shaved in severe infections, so that the shampoo has direct skin contact. Shampoos contain ingredients such as lime sulfur, coal tar or salicylic acid. Some shampoos are used every other day, tapering off in frequency over four to six weeks, to remove the dermatophytes. Topical dips or rinses, containing ingredients such as ketoconazole or miconazole, remain on the dog and are not rinsed off.

    Systemic Treatment

    • Systemic treatment controls the dermatophytes from inside the body. These oral medications, such as griseofulvin and itraconazole, can upset your dog̵7;s digestion and are given with food. Treatment is usually four to eight weeks as the disease appears to be gone in two or three weeks, but the dermatophytes are still in the hair follicles. Depending on the infection, your dog may benefit if systemic medication and topical shampoos are used at the same time. This combination treatment attacks the dermatophytes from inside and outside the body.

    Home Treatment

    • Treatment extends to the dog̵7;s environment. His bedding contains fungi, and the kennel area is contaminated with fungi-tainted hair. Wash or replace the dog bedding. Choose a bedding cover that can be washed and disinfected in a mild bleach solution. Vacuum the dog area frequently during and after the treatment phase, discarding disposable vacuum bags. Disinfect hard surfaces with a solution of one cup bleach in a gallon of water. If people and pets are repeatedly infected with ringworm or dermatophyte infections, home treatment can be extensive such as replacing forced air filters weekly, vacuuming furniture and disinfecting all washable surfaces.