Q: I had to take my daughter to the dermatologist after she developed a rash on her arms and chest. When the doctor told me it was ringworm she got from our pets, I couldn’t believe it. Our dogs are so clean and healthy. What am I doing wrong?
A: Your dermatologist is not necessarily correct. In in cases where other dogs and humans in the household have no lesions, it’s likely that the single infected person or animal picked up ringworm from the environment (soil is a prime culprit).
Ringworm is not caused by worms. Rather, this common skin infection is caused by a fungus but it’s commonly called “ringworm” as a result of the characteristic ring-like lesions. The fungus Microsporum canis invades the superficial layers of the skin, hair or claws.
Because it thrives in moist environments, the fungus is especially persistent in humid climates and damp surroundings such as South Florida backyards. Ringmworm is readily transmitted from animals to humans and vice versa. (Kittens are notorious for their susceptibility.)
While symptom-free dogs are an unlikely source of infection, it is possible that one or more of your dogs is a carrier. To sort it out, your veterinarian can perform a simple fungal culture on each pet and examine their skin under ultraviolet light. Neither test is 100 percent effective, but it should give you peace of mind. So might treating your pets with topical dips or shampoos just in case.
The good news is that ringworm infections in healthy humans and pets are self-limiting, meaning that three months from now this infection will likely be a distant if unsavory memory.
Dr. Patty Khuly has a veterinary practice in South Miami. Her website is drpattykhuly.com. Send questions to firstname.lastname@example.org.