My cat has a bald patch but acts normal – what could it be?

A round, patchy bald spot is likely ringworm, a fungal skin disease commonly from Microsporum canis, causing circular or oval hair loss that spreads if the cat licks or scratches. Trim the fur around the spot for easier treatment, put on an Elizabethan collar to stop spreading by licking, then use an antifungal pet skin product such as a spray and compound ketoconazole ointment for about a week. If it does not improve, take the cat to a vet for a skin exam and medicated bath to rule out other causes.