The rings usually start small and then expand outward. These diseased areas are more likely to be found on the face ears tail and feet among other places. How To Know If Your Cat Has Ringworm What To Do Ringworm In Cats Cats Ringworm Hair loss occurs when the fungi infect the hair shaft resulting in weakening of the infected hairs. . 10 Ways to Spot the Disease. Over-grooming with the cat itching or biting at its skin. The clearest and most common clinical signs of feline ringworm include the following. Onychomycosis which causes circular lesions with rough and scaly centers. Ringworm of the body tinea corporis is a rash caused by a fungal infection. Yes ringworm is contagious to people and is caught through touching an infected cat. More specific tests include a trichogram fungal culture submitted to a lab a PCR test or even a DTM test. It can sometimes be diagnosed with a specialized light called a Woods