What if Your Dog Has a Circle on His Fur?

If you notice a small circle on your dog's skin during a bath or a snuggle session on the couch, don't panic. It's likely the first sign of ringworm or demodectic mange, both common and treatable conditions that can affect dogs.

Despite its name, ringworm is not actually a worm. Ringworm is a type of fungus that invades the hair follicles, usually on the dog's face, ears, paws and front legs. It usually looks like a small circle of raised bumps, with a red, scaly center. If left untreated, ringworm can spread across the whole body, often resulting in secondary infections as it spreads. Ringworm is highly contagious and is easily spread to other pets in the home and even the human residents.

If the ringworm is just in one spot and hasn't spread, it's fairly easy to treat. Most over-the-counter antifungal creams, similar to the ones used for athlete's foot, can be used to treat ringworm. Look for a medication that contains miconazole and apply it to the infected spot twice a day. The lesions should begin to clear up in two to three weeks. If the ringworm has spread, your pup may need oral medication and dips to clear up the infection. Since ringworm is so easily spread, be sure to wear rubber gloves when applying the medication, wash your hands often and wash your dog's bedding regularly.

Demodectic mange (also called demodex) is a skin disease caused by tiny mites. Almost all dogs are carriers of demodex mites, and most dogs get them right after they are born from their mother. Dogs with healthy immune systems rarely have any symptoms from the mites, but dogs who are young, old or sick will often develop skin lesions that looks like small circles. Sometimes stress can cause an outbreak, because stress often lowers the immune system. Since most dogs already have mites, demodex is not considered contagious. Occasionally, people can be affected by the mites, although this isn't common.

If your pup only has a few spots of demodectic mange, it will often heal on its own. The most important parts of treating demodex are good nutrition and lower stress. If the mange has spread to several places, most vets will use ivermectin to treat the mites. If your pup has a sensitivity to ivermectin or resists because of the taste, you can also talk to your veterinarian about mitaban dips. Regardless of the medication you choose, demodectic mange that has spread beyond a few small places on your dog should be treated under a vet's supervision.