Despite its name, ringworm is caused by dermatophyte fungi such as Microsporum canis. Cats, especially kittens and long-haired breeds, are frequent carriers and may show minimal symptoms while spreading spores throughout the home. Dogs typically display more obvious circular bald patches. Diagnosis may involve a Wood's lamp (some strains fluoresce), fungal culture, or PCR testing. Treatment combines topical antifungal shampoos or creams with oral antifungal medication for several weeks. Thorough environmental decontamination is essential because spores persist on bedding, furniture, and grooming tools for months. Ringworm is zoonotic, so household members should take hygiene precautions.