Ringworm, or dermatophytosis, is one of the more common skin conditions affecting pets of all shapes and sizes. Despite its name, ringworm is not caused by a worm but by protein-eating fungi that invade the hair shaft and the surface of the skin.
While there are many species of ringworm, Dr. Alison Diesel, a clinical associate professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, said that Microsporum canis is the most common that affects dogs and cats.
The fungus can be spread animal to animal, as well as animal to human through direct contact with the infected animal or with whatever the infected animal had come in contact. Diesel noted that shared brushes, bedding, clippers, cages, and the surrounding environment can be sources of infection for this organism.
The most common identifier of ringworm in dogs and cats is a circular area of hair loss. Generally, there is also a ring of redness and scales surrounding the alopecic area, according to Diesel.
“The hair loss often starts in a very circular formation but can spread and be more generalized,” Diesel said. “Small red bumps and crusts can also be present. Body areas most affected include the face, ear flaps, and paws; however, any surface of the body can be effected.”
Once symptoms have been noted, Diesel advises owners to consult a veterinarian as soon as possible. The veterinarian will likely recommend performing tests such as cytology—to rule out other causes, such as bacterial infection or mites—as well as a fungal culture—for ringworm to identify the species of fungus involved in the infection. Newer tests may also be recommended and provide more rapid results.
“Depending on the animal species infected with ringworm, as well as the severity of the disease, ringworm can be treated with topical therapy and/or oral medication to address the fungus,” she said. “Topical therapy may include creams or ointments; however, these tend to not be very effective, especially in cats. Rather, a full body shampoo or dip containing antifungal ingredients is recommended.”
After receiving the ringworm diagnosis and the recommended treatment plan, Diesel stresses the importance of disinfecting any and all exposed areas in your pet’s environment.
“Environmental decontamination will be key in effectively eradicating the infection. This involves isolating the infected animal to a readily cleaned area, bleaching all able surfaces, steam cleaning, and the use of other cleaning products,” she said.
One of the most important things for owners to remember is that there is not a quick fix for ringworm, and, often times, it can take six to eight weeks to treat the infection. With a little patience, a lot of cleaning, and the recommendations of a licensed veterinarian, ringworm can be effectively and efficiently treated.
Pet Talk is a service of the Texas A&M College of Veterinary Medicine & Biomedical Sciences.