Nutria dermatophytosis (ringworm)

What is it?

Dermatophytosis, better known as ringworm, is an infection of the skin and hair caused by microscopic fungi called dermatophytes. In coypu, it mainly affects young animals and weakened subjects or those living in unhygienic breeding or captivity conditions. This disease is not dangerous in itself but it is very contagious, both between coypus and between other animals and humans. It is therefore closely monitored wherever coypu are raised or handled regularly.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Causes and risk factors

The disease is caused by filamentous fungi from the dermatophyte group, including species of the genera Trichophyton and Microsporum, which feed on the keratin present in hair, skin and claws. These fungi produce very resistant spores that can survive for a long time in the environment, on breeding equipment, bedding or cages.

Young coypu are more susceptible because their immune systems are still immature. A humid, poorly ventilated or crowded environment favors the survival of fungi and the spread of disease. Stress, an unbalanced diet, a concomitant illness or anything that weakens the animal's natural defenses increases the risk of infection and the severity of lesions. Poor hygiene of breeding equipment is also an important factor.

Transmission

Transmission occurs by direct contact with an infected animal or by indirect contact with contaminated equipment: cages, bedding, handling tools, hands of the handler. Fungal spores can persist for several months in the environment, making eradication difficult on farms. The disease is zoonotic: it can be transmitted to humans, in particular to children, the elderly or people with weakened immune systems.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

Treatment

Treatment generally combines local antifungal treatment, applied directly to the lesions, and sometimes general antifungal treatment prescribed by the veterinarian in extensive forms. Clipping the hair around the lesions can make it easier to apply treatments. Rigorous and repeated cleaning of the environment is essential alongside the treatment of the animal to avoid relapses.

Prevention

Possible complications

Without treatment, the lesions can spread and become superinfected with bacteria, which complicates healing. The disease can also spread quickly throughout an entire flock. In humans in contact, it can cause uncomfortable skin lesions, generally benign but sometimes stubborn.

When to see a veterinarian

Transmission to humans

Coypu moth can be transmitted to humans through direct contact with the animal or its contaminated environment. It causes red, rounded and sometimes scaly patches on the skin. Medical advice is recommended in the event of suspicious skin lesions after contact with a coypu, particularly in children or immunocompromised people. Washing your hands and wearing gloves when handling significantly reduces the risk.

Prognosis

The prognosis is generally good in healthy animals, with recovery in several weeks under appropriate treatment and good hygiene. In weakened subjects or in the event of delay in treatment, the course may be longer and the lesions more extensive.

Frequently asked questions

References

CDC — Centers for Disease Control and Prevention

MSD Veterinary Manual

Content reviewed by the TunisieVet editorial team · Updated 17 September 2026