Causes of Ringworm in Dogs
Despite its name, ringworm has nothing to do with worms. It gets its name from the circular areas of hair loss, surrounded by a red ring, that classically accompany the condition. Also known as dermatophytosis, ringworm is caused by one of several different fungal organisms. The species of ringworm fungi that most commonly infect domestic dogs and cats are Microsporum canis, Microsporum gypseum andTrichopyton mentagrophytes. All of these fungi thrive in the non-living outer layers of the skin and in the hair follicles, hair fibers and toe nails. Ringworm fungi rarely invade living tissue, although it can happen. Microsporum gypseum also can survive in the soil and tends to infect dogs in the late summer through early fall. Ringworm spores can survive in the environment for one year or more.
Ringworm is extremely contagious. It is spread by direct physical contact with fungal spores in the soil or on the hair of an infected animal, which may be found on rugs, carpets, combs, brushes, toys, furniture or bedding. People can become infected with ringworm by coming into contact with hairs from their infected pets, and vice versa. Ringworm infections are especially common in hot, humid climates. Ringworm usually is self-limiting, which means that it usually resolves on its own in a matter of months. However, it is best to treat this infection promptly, so that it doesn’t spread to other pets and to people. Veterinary personnel and owners should be very careful when handling animals that have a ringworm infection. Gloves should be worn during grooming and when applying topical medication to treat this condition. Children are especially susceptible to becoming infected with the fungi that cause ringworm.
Prevention of Ringworm Infection
The best way to prevent ringworm is to prevent contact between infected and non-infected animals and people. Outbreaks of ringworm infection are more common in young dogs and those kept in high-density living conditions, such as pet stores, puppy mills and animal shelters.