Conditions/Small Mammals/Ringworm

What is it?

Ringworm is a common fungal infection which affects the skin. Its name refers to the way in which the infection appears on the skin, as the rash presents as ring-shaped, often red in colour. It’s important to clarify that ringworm is a fungal infection that is not caused by an actual worm.

Ringworm is a zoonotic disease that can be passed between humans and animals due to close contact. This can be from either direct contact or from a third party such as bedding and towels.

What causes it and how can it be prevented?

Ringworm is a fungal infection caused by a set of fungi called Dermatophytes. The most common type that causes ringworm in rodents, especially rats, is known as Trichophyton mentagrophytes. Ringworm often presents when a new rodent is added to a group of animals, such as to a colony of rats or mice. In most cases, this new member can be responsible for bringing ringworm into the group. Ringworm can also be found in warm, moist environments where it is able to grow.

Ringworm can be prevented by:

Isolating new pets for a few weeks to determine that they are ringworm free. They can then be introduced to other animals.

Keeping a good level of hygiene within cages

Regularly changing bedding and litter as well as washing hides and hammocks

Using a suitable and safe antifungal disinfectant solution to clean all aspects of the animal's environment and allowing to air dry. Your vet will be able to recommend a suitable one

Maintaining good hygiene of the animals, allowing for regular grooming sessions

What animals are at risk?

As ringworm is zoonotic, all animals are at risk, including humans. Rats, Guinea Pigs, Mice, Rabbits, Ferrets and Hamsters are all prone to ringworm as well as Dogs and Cats.

What are the clinical symptoms and signs?

Ringworm symptoms are the same, no matter if it appears on humans or animals. An animal's fur may make it harder to notice ringworm, so you may have to carefully inspect the skin by wearing gloves if you notice your rodent is itching a lot. Symptoms can include:

Dandruff present on the fur of the animal

Scaling or crusting of the skin

The skin appears to be red and sore

Red lesions are commonly found on the head, back of the neck, chest or forelimbs

Patches of hair loss (alopecia)

A red rash which is often circular in appearance

If you notice any of these symptoms, speak with your veterinary practice for advice. However, sometimes no symptoms are visible, but the animal is still infectious. This is why all animals in a group may need to be treated even if not all are showing symptoms.

How can it be diagnosed?

A veterinary surgeon will use a variety of methods in order to diagnose ringworm. It is important to make sure that ringworm is not confused with mites. Tests that may be done include:

Clinical exam: Your vet may be able to diagnose ringworm based on the typical symptoms found with ringworm, such as a circular rash that is red in appearance.

Fungal culture: In some instances, a swab may be taken from the affected area. This swab can be sent to an external laboratory which will determine which strain of ringworm fungus is present.

Woods lamp: A lamp may be used to see if ringworm shows up on the skin. A Woods lamp emits an ultraviolet light which illuminates the ringworm fungal secretions. The secretions will appear yellow and green in colour under the light from the Woods lamp. Nowever, not all ringworm fungus shows up when a woods lamp is used, so additional diagnostics may be required.

Microscopic examination: A hair sample can be plucked from the affected animal. Some veterinary surgeons may be able to observe fungal spores attached to the hair.

How can it be treated?

Ringworm is usually a fairly mild condition that is easily treated. The most difficult part of the treatment will be trying to minimise the spread of the fungal infections to other animals. All aspects of the animal's enclosures should be thoroughly cleaned and the infected animal should be isolated if kept as part of a group. In some instances, all animals may need to be treated to avoid re-infection. Treatments may include:

Topical medication: Rodent-safe anti-fungal creams and ointments may be prescribed by the vet to apply directly to the rashes that have appeared on your animal's skin. In extreme cases where ringworm has affected a large area of skin, an anti-fungal shampoo may be prescribed.

Oral medication: A veterinary surgeon may prescribe oral treatments to help relieve symptoms of ringworm and treat the infection.

Deep clean the environment: Ringworm lives on skin and hair, so the fungus can be shed into the environment once the hair and skin sheds from the body. It is important to vacuum the living area of the animals and clean the environment with an appropriate fungicidal disinfectant solution. If you are worried about yourself catching ringworm, it may be beneficial to deep clean communal household areas and change your bedding.

If you think you may have ringworm, seek attention from a human health professional.