Emergencies and making appointments

96 Avenue Carnot 11100 Narbonne

Monday to Friday from 8 a.m. to 7 p.m. and Saturday from 8 a.m. to 3 p.m.

SHEET Dermatophytosis in dogs
Health info sheet

Dermatophytosis in dogs

Commonly called “ringworms”, dermatophytosis are superficial mycoses of the skin caused by the presence of microscopic fungi of the genus Microsporum or Trichophyton.
The source of contamination varies according to the type of dermatophyte: dog, cat, environment, rodent. Contamination occurs through direct contact with an affected animal or through contact with microspores present in hair, dander, the environment, sleeping areas, brushes, clipper combs, transport cages, etc.
The most affected animals are rather young, but adults can also develop dermatophytosis. In the presence of a generalized form in an elderly animal, a cause of immunosuppression must be sought (cancer, hypercorticism, cortisone treatment).

The classic clinical appearance is that of rounded single or multicentric lesions with hair loss, presence of scales, crusts. Facial involvement is common in dogs, but lesions can be found anywhere on the body. Itching is rare but may occur in some cases. The lesions may tend to generalize with a dull, oily, scaly appearance of the coat. Dermatophytosis can take on non-specific, sometimes confusing clinical aspects, which can hamper their diagnosis.
The diagnosis is based on the clinical examination and the performance of additional examinations:
  • Wood's lamp examination in a dark room: certain strains of Microsporum give a green fluorescence in the presence of ultraviolet rays. A positive examination strongly reinforces the suspicion of ringworm but a negative examination does not exclude it.
  • Examination of hair and scraping products under the microscope: visualization of microspores and altered hairs.
  • Reference exam: cultivation of hair, dander, harvested from the animal and sent to a laboratory specializing in veterinary mycology. Identification makes it possible to confirm the diagnosis of ringworm but also to possibly identify the source of contamination.
Dermatophytosis can regress spontaneously in three months. In the meantime, the animal was able to contaminate other dogs, its masters and those around it. It is therefore recommended to treat. The treatment is relatively long (about 45 days) and must be methodical. The principle is to treat then redo a culture and to stop treating only when the culture comes back negative.
The management of a sick dog is based on three points:
  • regular application of topical antifungal products to the body. Thorough mowing is often necessary.
  • administration of oral antifungal drugs. Given the duration of treatment and the possible side effects of these drugs, regular monitoring is recommended.
  • treatment of the environment with suitable products to prevent new contamination.
Share by: