Dermatophytosis, or ringworm, as it is commonly known, is not a worm at all, but a fungal infection that is zoonotic (it can cross between different species of animals). While ringworm poses little health risk to dogs, it can be transmitted to others in the household, and should be treated accordingly.
Types of Ringworm
There are three different types of ringworm that commonly affect dogs: microsporum canis, which prefers dogs and cats; trichophyton mentagrophytes, which affects many animals; and microsporum gypseum, a type of ringworm commonly found in wet, muddy soil. All of these can be transmitted to humans.
How Ringworm is Transmitted
Ringworm spores are shed by an infected animal, and can exist in the environment for more than 18 months.
First Appearance of Symptoms
The first appearance of ringworm symptoms in dogs is generally 10 to 20 days after initial contact with the fungal spores.
How it Looks
Ringworm generally manifests itself as a round, patchy spot of missing fur that may be red, itchy and scaly-looking. Several other conditions look this way as well, so it is advisable to visit a vet for confirmation.
Treatment of Ringworm
In less severe cases of ringworm, the infection will clear up on its own within two to four months in a healthy dog. More severe cases may require anti-fungal treatments prescribed by a veterinarian.
Prevention Of Ringworm
There is no reliable vaccine for ringworm in dogs. The best prevention is to avoid exposure to environments that are known to harbour ringworm, and to avoid animals that have or are undergoing treatment for the fungal infection.