Ringworm in Dogs: How to Treat and Prevention Tips

Red, circular skin lesions: this tell-tale sign of ringworm is unmistakable, whether it appears on you or your dog. But despite its name, ringworm in dogs isn't always a round lesion or a worm— it's a common skin infection that's highly contagious.

In cases of dog ringworm, these lesions typically appear on the face, ears, tail or feet. While these infected areas are pretty easy to spot, ringworm can also spread to other, more hidden, areas of your pet's body, which can make its transmission all too easy.

The good news is that while dog ringworm is pesky, it's also highly preventable and fairly easy to treat.

How Is Ringworm in Dogs Spread?

Dogs often acquire ringworm — or dermatophytosis, as your veterinarian might refer to it — from digging. It's relatively easy to treat and doesn't cause severe disease. However, ringworm in dogs can be difficult to manage, due to the fact that it's highly contagious and can be transmitted via fomites.

A fomite is any object or material that can carry an infection. In short, anything your pet touches can harbor and transmit ringworm to other dogs, cats or people. Any brushes, bedding, food, water bowls or toys — anything your dog comes in contact with — should be disinfected if ringworm enters the picture.

Additionally, any infected dog is considered highly contagious to other animals and humans. Wear gloves or wash your hands and clothes after handling your pet, and keep them quarantined until your vet declares that they're free of infection.

Does Ringworm in Dogs Affect All Breeds?

Not all dogs that come in contact with ringworm will show signs of an infection. Ringworm infections depend on the type of fungus, as well as the dog's age, relative health, nutrition and grooming.

Any dog can develop a ringworm infection, however, certain age ranges and breeds are more at risk. In an article for DVM360, veterinary dermatologist Anthea Schick says Boston terriers, Yorkies and Jack Russell terriers are all prone to contracting ringworm. Very old dogs, puppies and dogs who have a suppressed immune system, she continues, are at an increased risk for developing ringworm.

Dogs with ringworm are contagious to humans. If your dog has been diagnosed, or if you suspect they may have ringworm, do not handle them and then directly touch your skin. Wash your hands after every touch, and if you notice any red, circular itchy spots on your own skin, call your doctor.

How Is Dog Ringworm Diagnosed and Treated?

Your vet will usually diagnose ringworm via physical examination and one or more simple lab tests. The Wood's Lamp, fungal culture and direct examination of hairs under a microscope are the most common ways of diagnosing ringworm. Occasionally, ringworm in dogs is diagnosed via skin biopsy or polymerase chain reaction (PCR) from samples sent to a reference lab.

Ringworm is treated with antifungal medication, either topical, oral or a combination of both. There are several lotions, creams and shampoos available by prescription from your vet as well. Ringworm can also be treated with prescription-only oral antifungal medication.

Dogs are often shaved in the area of infection to help prevent the spread of disease through contaminated hair. In some cases, ringworm infections can return; however, treatment in these dogs can still speed healing and reduce the likelihood of the disease being transmitted to other animals or humans.

How to Decontaminate Your Home After a Ringworm Diagnosis

Remember, ringworm loves to travel and infect new hosts via fomites, which is why a key part of treating it is to disinfect your home. If your dog has ringworm, vets recommend:

• Confining them to a single area that can be cleaned easily. If that area is carpeted, vacuum it once a day.
• Using diluted bleach (1:10 mixture in water) or an all-purpose cleaner to clean all nonporous surfaces twice a week (i.e. counters, tabletops, etc.).
• Wiping all floors and walls with dry cloths once a week.
• Washing all pet bedding on the hottest setting weekly, and throwing away any bedding or toys that are hard to clean.
• Changing your clothes immediately after handling them, and putting potentially infected clothing in the washer as soon as possible.

In severe cases in which you have children at home or more than one pup, you may also want to clean your home's air ducts and replace any air filters.

Is Ringworm in Dogs Preventable?

One way to prevent ringworm is to not let your dog dig in rodent holes, as this is how infection often occurs. The likelihood of a ringworm infection can also be reduced by making sure your dog is in otherwise good health.

If you take your dog in once or twice a year for vet wellness visits, follow all their recommendations and practice preventative nutrition by feeding them a complete and balanced diet, you'll be well on your way to keeping ringworm away.