Dermatophytosis (Ringworm)

What is Dermatophytosis?
Both dogs and cats can develop a fungal infection that can affect the hair, skin and nails. Ringworm is the common name for the most common form of dermatophytosis.  Dermatophytosis is zoonotic in that people can get ringworm by coming in contact with their dogs.

How does my dog get Dermatophytosis?
Dermatophytosis is caused by contact with a particular fungus, either in the environment or on another infected animal, although not all contacts will result in infection. Immuno-compromised, immuno-suppressed or pets that are taking corticosteroids are more likely to develop the condition. Younger animals are more susceptible.

How do I know if my dog has Dermatophytosis?
You may notice patches or circular areas of hair loss. The area may also be scaly or darkened, and in some cases, itchy. In some animals, one or more nail beds may be abnormally crusty or overgrown.  Because other conditions can cause similar looking hair loss, your veterinarian will need to make a definite diagnosis.  A Wood's lamp examination will reveal suspicious hairs, but relying only on this method can result in over diagnosis.  Ideally, the suspicious area is then cultured for fungus.  Microscopic examination of the hair may also be useful.

What can I do about Dermatophytosis?
Depending upon the severity and other variables, treatment may be local or systemic. You may be advised to clip long hair and to treat with medicated shampoos.  Your veterinarian may prescribe oral medications; some of these medications are absorbed better when taken along with either a fatty meal (in the case of griseofulvin) or an acidic meal (in the case of ketoconazole).  Quarantine your affected pet from any other pets so that the others don't catch the condition. It is also important to treat surfaces (including your hands) that the infected pet may touch with a dilute bleach solution so that the fungal spores aren't transmitted by way of them. Treatment can be especially frustrating in households in which animals re-infect one another. Spontaneous recurrence can occur in seemingly cured animals.

Is there anything I can do to prevent my dog from getting Dermatophytosis?
Prevent your pet from mingling with affected animals, and wash your hands after touching affected animals.  Good nutrition helps prevent susceptibility to some extent.  Preventive drugs are being evaluated but none have yet proven effective.

Are there certain breeds that get Dermatophytosis more often?
Ringworm does not have any particular breed indications.