Ringworm is not really a parasite or a worm; it is actually caused by a fungus, some types of which are zoonotic, meaning it can be transmitted from pet cats to humans or other species. The fungus can also be acquired from contaminated soil or objects. Juvenile cats, senior cats, ill, and those with suppressed immune systems tend to be more at risk of being infected. Some cats are chronic carriers and they are important sources of infection because they continue to shed the fungal spores of ringworm without displaying any symptoms of the infection. While most cases of ringworm resolve on their own, it is a good idea to contact your vet clinic Norwalk, CA so the staff can instruct you on what to do. In order to confirm the initial diagnosis, your vet may recommend some tests that may include a fungal culture, biochemical profile, a thyroid function test, etc. to evaluate the function of the immune system.