Ringworm on Dogs

What is Ringworm?

Ringworm is caused by dermatophytes (fungi)

If you suspect your dog has ringworm, it's essential to consult with a veterinarian for a proper diagnosis. Ringworm is highly contagious and can spread through direct skin-to-skin contact with an infected person or dog, or by touching contaminated surfaces. It is also possible to contract ringworm from other infected animals. Treatment typically involves antifungal medications, which can be applied topically or taken orally depending on the severity of the infection. Keeping the affected area clean and dry is also important in managing and preventing the spread of ringworm. If you suspect you have ringworm, it's advisable to consult with a healthcare professional for an accurate diagnosis and appropriate treatment.

Ringworm Vet Inspection Vet checking dog for ringworm Sad vet puppy

Ringworm Identification

How to Identify Ringworm on Dogs

Circular Areas of Hair Loss:

Unlike in humans where a ring-like rash is common, dogs often exhibit circular, patchy areas of hair loss. These patches may have a crusty appearance.


Skin Redness and Scaling:

The affected skin may be red, scaly, or flaky, similar to the symptoms seen in humans.


Itching and Irritation:

Dogs with ringworm may itch and scratch the affected areas, although not all dogs show signs of discomfort.



Increased dandruff or skin flakiness can be observed in the affected areas.


Changes in Nail and Claw Health:

In some cases, ringworm can affect a dog's nails, leading to brittleness, discoloration, or deformation.


Variable Symptoms:

The severity and appearance of ringworm can vary greatly from one dog to another. Some dogs may have just a single lesion, while others may have multiple affected areas.


Asymptomatic Carriers:

Some dogs can carry the fungus without showing any symptoms, making it challenging to identify.

Taxonomy of Dermatophytes

Approximately 40 different known species of fungi can cause ringworm; the scientific names for this closely related group of organisms can be categorized into one of three genera: Trichophyton, Microsporum, and Epidermophyton.

These fungi are the cause of Ringworm and certain types can sometimes cross species barriers. Environmental factors can play a role in the spread and prevalence of certain types of ringworm. The following is a list of the most common:


Microsporum canis:

The most common cause in cats and dogs.

Trichophyton mentagrophytes:

Can affect both cats and dogs, often transmitted from rodents.

Microsporum gypseum:

A soil-associated fungus that can infect pets.


Tinea corporis:

This type affects the body and can cause red, scaly patches that form a ring shape.

Tinea capitis:

This affects the scalp and hair, often leading to bald patches or scaling.

Tinea pedis:

Also known as athlete's foot, it affects the feet, causing itching, burning, and scaling.

Tinea barbae:

This affects the face, causing redness, swelling, and pustules.

Trichophyton rubrum:

The most common cause of ringworm in humans, often affecting the feet (athlete's foot) and groin area (jock itch).

Trichophyton tonsurans:

Primarily causes scalp ringworm, particularly in children.

Microsporum canis:

Often contracted from cats and dogs, leading to ringworm on the body, scalp, or feet.

Microsporum audouinii:

Commonly causes scalp ringworm, especially in children.

Epidermophyton floccosum:

Mainly causes ringworm of the skin and nails.


Trichophyton verrucosum:

Common in cattle, causing ringworm of the skin.

Trichophyton mentagrophytes:

Can also affect cattle.


Trichophyton equinum:

Specifically affects horses.

Microsporum gypseum:

Can also be a cause in horses.


Trichophyton verrucosum:

Also affects sheep and goats.

Microsporum gypseum:

Less common, but can infect these animals as well.


Microsporum nanum:

Specific to pigs.

Trichophyton mentagrophytes:

Occasionally seen in pigs.

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