Why does my cat have a bald spot?

Any visible bald patch is a vet conversation. Common causes in indoor cats: over-grooming where the cat licks one spot until the hair is gone (often a stress, allergy or pain response), flea allergy dermatitis (yes, indoor cats get fleas), ringworm (a fungal infection contagious to humans), and other allergic, parasitic or hormonal conditions per Cornell. Cornell lists nutritional deficiencies, parasites, fungal infections, bacterial infections and environmental allergies as the main causes of significant coat problems. Symmetrical bald patches (mirror image on both sides) particularly suggest a hormonal or systemic issue.

When to call a vet: don’t wait this one out. A bald patch is information your vet wants to see, often soon. Earlier diagnosis usually means a shorter treatment course.