Anything with "worm" in the name sounds pretty disgusting, right? But ringworm isn't caused by a worm at all — it's actually a skin infection caused by a fungus. While it's highly contagious to pets and humans alike, it can be treated relatively easily with some medication, a little time apart, and lots of love.
The clinical name for this common skin infection is dermatophytosis. It can infect dogs, cats, and pretty much any living creature, including humans. It's caused by a fungus that feeds on the protein of the outer layer of hair, nails, and skin.
The name "ringworm" comes from the appearance of the skin during infection: a circular, red, raised rash that resembles a worm in the shape of a ring. However, the infection does not always appear as a round rash (or lesion) on dogs — instead, you may see round patches of fur loss (called alopecia). These patches and lesions can appear anywhere on the body but are typically located on the face, ears, flanks, and tail. Other symptoms include:
Ringworm is highly contagious. The fungus can live on the skin, surfaces, soil, and other items such as clothing, brushes, towels, and bedding. If your pet is infected with ringworm, they remain contagious until they are treated or their immune system clears the infection. Even while undergoing effective treatment they remain contagious for about 3 weeks and in some cases multiple rounds of treatment can be required, especially if the fungus is still present in the environment (spores in the environment can stay infective for up to 18 months).
It's also zoonotic, meaning it can pass from animals to people and vice versa. Thankfully, most human adults with a healthy immune system generally do not develop disease from the specific types of ringworm-causing fungi found in animals – though other types of fungi can cause ringworm in healthy humans. Children, however, can get ringworm from infected pets, other children, or even the outdoors. Similarly, the elderly and people with a compromised immune system (such as those with certain diseases and those being treated with chemotherapy) are also susceptible. Therefore, children and those with compromised immune systems should not handle a pet with ringworm.
Ringworm may be annoying, but it’s relatively easy to treat. The good news is that ringworm infections in healthy dogs are usually self-limiting, meaning they will resolve on their own without treatment. However, if you suspect your dog has ringworm or has been exposed, you should see your veterinarian right away. They'll be able to properly diagnose ringworm and develop a treatment plan to clear up the infection as quickly as possible, helping prevent spread to other animals or people. A successful treatment plan is likely to include:
If treatment is stopped too early or the home and quarantine areas aren't regularly and thoroughly disinfected, reinfection can occur. The fungal spore can live in the environment for up to 18 months, so continue sanitizing for a while, even after you've completed the treatment.
Any human that develops skin lesions/rash should seek medical attention immediately. This is especially important for children, the elderly, or anyone with a compromised immune system.
Ringworm certainly isn't fun for you or your dog. But it's not the end of the world, and it's nothing to fear. With your veterinarian's guidance and a dose of patience and compassion, you can see your dog through this rashy situation and get back to games of fetch in the backyard in no time.