If your dog only has these hairless lesions, either circular or not, and no other symptoms, then you are probably looking at a case of Canine Ringworms. Canine Ringworm is not an actual worm at all, so do not panic. It is actually a fungus infection and with treatment is curable. This fungus infection occurs in the hair follicles, down deep in the skin. The fungus invades the hair follicle and damages the hair shaft, which will either cause the hair shaft to break off at skin level or to fall out. The skin lesions are caused by the spread of the infection.
Okay, so now you suspect that your dog may have Canine Ringworms, it is important to know that Canine Ringworms are highly contagious among animals and can even cross over from animal to people. The suspected dog should be isolated from all other pets and people and all pets and people should be inspected to make sure that they have not gotten the infection. Even dogs that are being treated can be contagious for up to three weeks.
The infected dog should be taken to the veterinarian for a diagnosis and to begin treatment. The veterinarian will perform a physical exam, carefully inspecting the skinless lesions. A Wood’s light, an ultraviolet lamp, may be used to locate any fungi, as some fungi will glow when an ultraviolet lamp is shown on them. The veterinarian may also take a small sample of hair from the infected area to culture.
After the veterinarian has diagnosed the infected dog with Canine Ringworms, the veterinarian will prescribe a treatment, such as antifungal shampoo, lime sulfur dip, topical antifungal cream, oral antifungal cream or body clipping. Antifungal shampoo is used for three weeks, with the dog being bathed in it every other day. The dog owner should allow the shampoo to stay on the dog for five minutes after lathering it up real good, and then rinse it out very well. Lime sulfur dip is used twice a week for up to six weeks. The dog owner should wear gloves and dip the dog into the solution, carefully soaking the entire coat. Topical antifungal cream is used once a day for ten days. The dog owner applies this cream directly to the skin lesions. This treatment should be used in conjunction with antifungal shampoo or lime sulfur dip. Oral antifungal medication, such as Griseofulvin, is given with a fatty meal, once a day for thirty days. In extreme cases, the entire body of the dog will be carefully clipped, removing the all dog’s hair so that treatment can better be given. With proper treatment, this infection can be cleared up and the dog will be well again.
Further treatment would include the dog owner bleaching any bedding, collars or anything the infected dog may have come in contact with. The owner should also either shampoo any other pets with the antifungal shampoo or dip them in the lime sulfur dip at least once to reduce the chances that they may have been infected as well.