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Ringworm in Dogs: Symptoms, Treatment & Prevention

sad french bulldog

Skin conditions are part of pet ownership, whether they’re from allergies, hot spots, or the dreaded ringworm. Ringworm is a fungal disease that is particularly common in puppies or dogs with compromised immune systems. It is especially troubling because it is also a zoonotic disorder, which means your pup can transfer it to you too.

Three types of fungi can cause ringworm. The most widespread is Microsporum canis, which accounts for over 2/3 of cases. The disease is appropriately named because of the telltale round bald patches that you’ll see on your dog’s coat. It can also affect their feet and claws, which can cause them to grow misshapen.

While it may look like it itches, ringworm doesn’t affect your dog this way, unlike in people, where it can make you quite uncomfortable. Secondary bacterial infections in canines and humans can cause additional symptoms, such as itchiness, redness, and swelling. These are signs of the body’s immune response. They also increase the risk of complications.divider-dog

Causes of Ringworm

Like many fungi, ringworm exists in moist and humid environments. These are also ideal places for bacteria to develop. That’s one reason that you should dry your dog promptly after they take a dip in the lake. The fungi exist in the soil, so it’s difficult, if not impossible, to avoid contact with it. Dogs that have free run of the backyard or hunting dogs are also susceptible.

The fungus resides in your dog’s hair. That’s one reason that you won’t necessarily see your pet scratching. How the condition proceeds depends on the health of your pup, including their overall skin condition, stress level, and age.

Credit: Kittima05, Shutterstock


Ringworm typically shows up first on a dog’s tail, feet, ears, and face. You may also see red, crusty spots or bumps that resemble acne. You may notice that your pup’s coat is brittle. The symptoms are straightforward, typically making a physical exam sufficient to identify the problem. However, your vet will likely use additional methods to diagnose ringworm, since a gold standard doesn’t exist.

An interesting trait of this fungus is that it can fluoresce under UV light using a device called a Wood’s lamp. It will glow with a yellow-green color. Unfortunately, detection by this method is not definitive, with it not being visible in a small percentage of pets. That said, it can help your vet rule out other conditions, such as food allergies.

Doing a fungal culture is a more reliable diagnostic method. Your vet will collect hairs from a dog that has shown the fluorescent color and try to grow it in a lab setting. The downside is that it can take up to 2 weeks before the fungus develops, thereby delaying treatment.


The first step for treating ringworm is to isolate your pet to avoid contact with other animals. If you can, confine them to a small area. It’ll make the other things that you must do much easier. It’s imperative to follow up with cleaning and vacuuming the rooms, carpets, and furniture that your pet may have used. We also suggest washing their bed or better yet, replacing it.

We strongly urge you to keep up this routine until the ringworm is gone. If not, your pet can reinfect themselves and start the treatment process all over again. You should also limit handling your dog. The same precaution applies to everyone in the household, especially the children. They are more vulnerable to contracting the disease.

It’s worth mentioning that ringworm spores don’t reproduce like mold. As long as your dog is infected, they’re still spreading them. Manual removal by cleaning is an effective way to control this condition and speed resolution.

Credit: Pressmaster, Shutterstock


Often, ringworm is self-limiting and does not require any interventions in healthy pets. The risk of this approach, however, is the possibility of secondary infections. Fungal diseases are notorious for their tenacity. The treatment is often lengthy, taking several weeks before it resolves. Your vet will likely use a two-pronged approach, with topical and oral medications.

Several drugs are available, including terbinafine, ketoconazole, or itraconazole. On a side note, the last one is also used to treat fungal infections in humans. Topical treatments are vital to cure this condition. Their primary function is to reduce the number of spores that the fungus sheds to avoid reinfecting the animal or other members of the household.

Your vet may recommend topical treatments, such as shampoos or dips that are similar to what you may use on your pet for fleas. It’s essential to continue with the schedule that your vet recommends. You’ll likely get the confirmation that it’s resolved once there is a negative fungal culture.


Prevention is the best cure. Early detection is also helpful. That’s one reason that regular grooming is vital for monitoring your pet’s skin condition. Ringworm is zoonotic, which means you can give your pup this fungal disease too. If you or your children develop it, avoid petting your dog and follow the same precautions.divider-paw

Final Thoughts

Ringworm is a common and irritating skin condition. Its unpleasant effects on your dog’s coat and skin are difficult to witness. The best approach is to act promptly if you notice any of the telltale signs. You’ll reduce your pup’s risk of complications and prevent family members from contracting this disease.

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Featured Image Credit: Mylene2401, Pixabay

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