Ringworm in Pets 101: What You Need to Know

Whenever a pet has lesions on the skin, pet owners tend to jump to the conclusion that it must be ringworm. While our vets at Leon Valley Veterinary Clinic diagnose ringworm in pets fairly frequently, we have found that most people don’t really know what they are looking for when it comes to this skin infection. 

Ringworm in pets is not an uncommon dermatological diagnosis, but do you know what you are looking for?

Getting a Grasp on Ringworm in Pets

To fight an enemy you must first understand it. Despite a very misleading name, ringworm in pets is not, in fact, a worm at all. Ringworm is actually a fungal infection more properly referred to as dermatophytosis. 

Dermatophyte spores live in the environment and soil, and contact with them can lead to the skin infection that we know as ringworm. Cats tend to be affected more often than dogs, and pets with weakened immune systems such as kittens are certainly more prone.

There are three species of ringworm that tend to cause trouble in our pets:  Microsporum canis, Microsporum gypseum, and Trichophyton mentagrophytes 

Symptoms of ringworm infection in pets include:

• Circular areas of loss
• Broken hairs
• Skin pigmentation
• Red bumps
• Itching
• Scales or crusts
• Infected nail beds
• Or, sometimes nothing at all (particularly in cats)

Some species of ringworm will fluoresce under a special black light called a Wood’s lamp, but typically ringworm must be diagnosed via fungal culture or biopsy. 

Despite its name, many ring-like skin lesions on pets are not ringworm. It is important to allow one of our expert doctors to diagnose the problem before assuming that ringworm is present.

Thankfully, ringworm is typically very treatable once appropriately diagnosed. Systemic or local medications as well as decontamination of the environment is needed. 

The Zoonotic Connection

Ringworm is a zoonotic disease, meaning that it can be passed between people and pets. It is important to remember, though, that ringworm in humans can be passed from one person to another. Many cases in people are contracted at places like a gym or public pool. People with lowered immune capacity are at higher risk.

Whenever ringworm appears in a person, it is important for that person to seek medical care to arrive at a proper diagnosis. 

If ringworm is diagnosed, it is reasonable to have your pets examined to be sure that one of them is not the source. Cats in particular can be carriers and shed spores into the environment without having any symptoms. It may be wise to culture cats in the home, especially any new additions. 

Ringworm is an annoying but typically treatable skin condition that, despite popular belief, is not a worm at all. Skin problems in pets can be hard to diagnose without further diagnostics, so it is important to make an appointment for us to take a look if you are noticing signs of a problem. The sooner we make a diagnosis, the sooner we can get started helping.