Tinea corporis, also known as ringworm or dermatophytosis, is a skin infection caused by various moldlike fungi, or dermatophytes -- it is not a worm. Tinea corporis is a zoonotic condition -- the fungi can infect both humans and dogs, who can spread the fungi to each other.
Many species of dermatophytes can contribute to a tinea corporis infection in you or your dog. The most common species that infect humans are Trichophyton rubrum and Trichophyton tonsurans. The common dermatophytes infecting dogs include Microsporium canis, Microsporium gypseum and Trichophyton mentagrophytes. Although the main species responsible for human or dog infections are different, all of these dermatophytes can cause tinea corporis in both humans and dogs.
Tinea corporis is highly contagious and can spread between dogs, humans and other animals in the home. Direct contact with infected skin spreads the infection, but this is not the only mode of transmission. The fungal spores can spread through contact with surface items, such as bedding, floors, furniture and even the dog brush. Simply petting your dog is enough for you to pick up the infection. Cats are common carriers of ringworm fungi.
If your dog encounters dermatophytes, symptoms of tinea corporis include dandruff or skin scales, skin redness, hyperpigmentation, itchiness and hair loss. In humans, ringworm symptoms include itchiness and a ring-shaped rash with a red outline and clearer center. The border of this ring may appear scaly.
Because the dermatophytes spread easily and between species, preventing possible transmission is essential. If you or your dog receives a tinea corporis diagnosis, you have much to do to take in order to prevent the spread of fungal spores. Fungal spores can survive in the environment for 18 months or more. These spores reside on bedding, flooring, ventilation ducts, air filters, carpets and drapes. A solution of 1 part bleach to 10 parts water kills the spores. After petting an infected pet, wash your hands. Isolate pets with an infection. If you have been diagnosed with ringworm, it is possible your dog has it as well. Even if he does not show symptoms, a vet check is recommended.
- Centers for Disease Control and Prevention: Definition of Dermatophytes
- The Merck Veterinary Manual: Dermatophytosis in Dogs and Cats
- NHS Choices: Causes of Ringworm
- PetMD: Ringworm in Dogs
- National Institutes of Health: Tinea Corporis
- The Humane Society of the United States: The Most Persistent Fungus Among Us
- BananaStock/BananaStock/Getty Images