Ringworm in Dogs

In spite of the name, ringworm is not actually a worm.

It is a skin infection caused by fungi which usually appears as a grey scaly hairless
patch anywhere on your dog's body.

Ringworm is quite contagious.

Dogs with an infection will shed hairs which are covered in fungal spores. These
spores are hardy and survive for long periods of time in the environment.

They can easily infect grazed skin, such as you'd find after a dog has been clipped, or if he has scratched himself. Infection can be spread from dog to dog through grooming equipment and bedding, and you're not immune either. Ringworm can also infect people, particularly those with a suppressed immune system.

Diagnosing Ringworm Reaching a diagnosis of ringworm can be difficult. Even though the typical appearance of an infection is grey scaly skin, a fungal infection can look like many other skin conditions. Your veterinarian has a few tools at their disposal to confirm their suspicion of ringworm.

Woods Light
The most common ringworm fungus in dogs will often fluoresce green when under ultraviolet light. A Woods Light isn't always diagnostic though; because there are other fungi that can cause ringworm, 50% of infections won't fluoresce and you'll need to use other diagnostic methods.

Microscopy
If your vet has a look at some of your dog's hairs under the microscope, they may be able to see spores. They're not easy to see, so if there are no spores, it doesn't necessarily mean there's no ringworm.

Fungal Culture
This involves putting hair and skin flakes on a special gel and trying to actually grow the fungus. This will not only definitely diagnose ringworm but your vet will be able to tell exactly which species of fungi is causing the problem. Unfortunately, it will take 10 days for the fungi to grow, and in this time, your dog could have spread infection far and wide.

Biopsy
This is the definitive way to diagnose ringworm quickly, but it can also be costly.

Treating Ringworm
It takes a lot of time, effort and commitment to treat ringworm, particularly in a multi-dog household. You not only need to treat your dogs, but also clean up any fungal spores in the environment.

If you only have to deal with a small patch of ringworm, you may be able to get away with just using a rinse on that area. More severely infected dogs are treated with tablets or rinses. Griseofulvin is the most common oral medication used but itroconazole is another good option. Both may cause birth defects so make sure your female won't get pregnant while she is being treated.

Clean your environment by bleaching anything that can be bleached with a 1:10 solution of normal household bleach and water. Vacuuming and steam cleaning can help to disinfect your floors. Wash all your dogs' bedding and shared brushes thoroughly. It's important that you treat your dog until your veterinarian gives you the all-clear. Even if he looks like he has fully recovered, there may still be spores in his skin that will reinfect him when treatment has stopped.

Ringworm is an annoying condition that can be difficult to clear up but fortunately, in most cases, it won't have any serious or long lasting effects on your dog's health.