Ringworm, Your Pets And You: A Not So Happy Relationship

8 February 2016
 Categories: , Blog


If your dog or cat develops circular red patches of hair loss on its back, a trip to your veterinarian could reveal that it has ringworm. Although generally not serious, this diagnosis does have consequences. It's a ring you definitely don't want to get or give. Here's some information that can keep you from doing either.

What Is Ringworm?

Ringworm is a common fungal skin infection in dogs and cats caused by an organism called a dermatophyte. The dermatophyte lives in the hair follicles and feeds on the dead outer layer of the animal's skin. It's very contagious, as well as zoonotic, which means animals can pass the disease to humans and vice versa. It is most common in young animals and children or those individuals with compromised immune systems, such as those fighting other infections, those with auto immune disease, or patients undergoing cancer treatment. It causes itchy red lesions and circular patterns of hair loss on the head, chest, back and tail.

How Is Ringworm Transmitted?

Ringworm is transmitted through direct contact between infected animals and humans. It can also be acquired through the environment as the dermatophyte spores can live in the soil, bedding or carpet for weeks. It takes 10 to 12 days after exposure to the spores for symptoms to appear.

How Is Ringworm Diagnosed and Treated?

Although your furry friend will likely display the tell-tale red rings and hair loss, there are other skin conditions that can cause similar symptoms so this is not a reliable means of diagnosis. If your veterinarian suspects ringworm, he or she will likely use a Woods lamp, which is a special ultraviolet light used to screen for ringworm. Under the light, an infected area shows up as a fluorescent yellowish-green. The Woods lamp is not 100% effective, so a negative result should be investigated further by culturing the lesions to determine the presence of the fungus.

Your vet will likely prescribe an appropriate topical ointment and antifungal shampoo. In more serious or widespread infections, he or she may prescribe oral medications to treat the condition. If you have other pets in the house, you will likely want to treat all animals simultaneously. Generally, you'll need to continue the medication for 6 weeks or longer.

How Can you Prevent Infection and Transmission?

Of course the best treatment is prevention, but that's easier said than done. Ringworm spores prefer warm, damp places and although it's difficult to keep your pet away from these areas, there are steps you can take to minimize the risk of infection. Regularly wash your pet's bedding with a solution of one pint chlorine bleach per gallon of water. Use this solution to disinfect your pet's grooming tools as well as any other areas he or she spends time in. Vacuum frequently and try to restrict your friend to areas that are easily cleaned such as wood or tile flooring. Don't let your pet near any animals diagnosed with or showing signs of ringworm.

Your dog or cat will remain contagious for at least 3 weeks. Do not let other household animals have contact until your veterinarian has deemed your animal non-contagious. Avoid contact with your pet's infected lesions and especially keep younger family members or friends away from your infected animal. If you're not diligent, you may be responsible for a ringworm outbreak in your child's school or neighborhood.