Diagnosing Dermatophytosis

Valerie Fadok, DVM, PhD, DACVD, dermatologist in the Veterinary Specialty Team at Zoetis, discusses the diagnosis of dermatophytosis.

Interview Transcript (slightly modified for readability)

“The gold standard for the diagnosis of dermatophytosis has been the fungal culture. But like any test, it’s not perfect, it takes time. You can have false positives and false negatives. I’m very excited about the potential for using PCR in the diagnosis of dermatophytosis.

Up until recently there were a couple of PCR tests offered that didn’t seem to help as much as I would have hoped. But IDEXX has a PCR [test] that allows us to distinguish among three major causes of ringworm in animals, [Microsporum] canis, [Microsporum] gypseum, and Trichophyton species, and they require the same samples that we use for culture. Of the PCR tests I’ve seen, this one seems to be the most promising. What we look forward to are peer reviewed publications to show the value of the PCRs. You can get a result back in a day or two rather than waiting 2-3 weeks for a fungal culture. When you’re dealing with, say, a kitten in a home full of children, or a caterie, or a shelter, it’s very important to get a diagnosis quickly, so you can start treatment if it’s positive.”