Dermatophytosis in Ferrets
Dermatophytosis is a rare form of fungal infection in ferrets affecting primarily the hair, nails (claws), and sometimes the uppermost parts of the skin. It can affect both males and females regardless of their age. Moreover, an infected ferret can spread the infection to other animals.
Symptoms and Types
Symptoms of dermatophytosis include accumulations of surface skin cells, such as seen in dandruff (scales); poor hair coat; reddened skin (erythema); darkened skin (hyperpigmentation); itchiness (pruritus); and hair loss (alopecia), which may be patchy or circular. Other indications of dermatophytosis that are readily apparent on the skin are raised, rounded, knotty (nodular) lesions known as granulomatous lesions, or boils, and raised nodular lesions. There may also be inflammation of the claw folds (paronychia), the folds of skin bordering the nail.
Ferrets most commonly develop dermatophytosis because of infections with the fungi Microsporum canis or Trichophyton mentagrophytes. The incidence of each fungus varies according to your geographical location.
Diseases or medications that decrease the body's ability to develop a normal immune response (known as immunocompromising diseases, or immunosuppressive medications, respectively) can increase the likelihood that your ferret will be susceptible to a fungal infection of the skin, hair, and/or nails, as well as increase the potential for a more severe infection. Environments that are densely populated with animals (for example, in an animal shelter or kennel), or where there is poor nutrition, poor management practices, and lack of adequate quarantine period, will also increase risk of infection.
To diagnose dermatophytosis a veterinarian will want to rule out other causes for hair loss, which may include ferret adrenal disease and seasonal flank alopecia, a form of hair loss that occurs during the breeding season. Contamination with ear mites, fleas and parasitic infections can also result in characteristic forms of hair loss or alopecia. Your veterinarian will also perform a fungal culture of skin clippings, a microscopic examination of a sample of hair, and possibly a skin biopsy.
Most ferrets can be treated on an outpatient basis, and some milder cases may even resolve without treatment or intervention. However, quarantine procedures should be considered due to the infective and zoonotic (transmittable to humans) nature of some types of dermatophytosis. If your veterinarian needs to prescribe antifungal medications, the use of an Elizabethan collar (a wide collar placed around the neck) is recommended to prevent ingestion of antifungal creams applied to the ferret's skin.
Living and Management
A fungal culture is the only means of truly monitoring your ferret's response to treatment. Many animals will improve clinically, but remain fungal culture positive. It is advisable to repeat fungal cultures toward the end of treatment, and continue treatment until at least one culture result is negative. In resistant cases, fungal cultures may be repeated on a weekly basis, and treatment continued until two to three consecutive negative results are obtained.