Why is my cat losing hair?

But true hair loss — bald patches, thinning spots, or a coat that suddenly looks sparse — is not normal shedding and almost always has an underlying cause.

Parasites are the number one reason. Fleas, and the flea allergy dermatitis they trigger, cause intense itching and hair loss over the lower back and tail base. Ear mites and other mites, such as Demodex and Notoedres, cause crusty patches on the head, ears, and neck. Ringworm, a fungus, creates circular bald areas with scaly edges. Allergies to food or to environmental triggers like pollen and dust produce itching and over-grooming. Psychological causes matter too: stressed cats groom obsessively, licking the belly, flanks, or inner legs bald, and pain from arthritis or cystitis makes a cat lick one spot repeatedly. Finally, hormonal disease such as hyperthyroidism or Cushing's disease can thin the coat.

Start by parting the fur to see whether the skin is red, scabby, crusty, or broken, and note exactly where the loss is. Keep up monthly flea prevention with a product your vet recommends, treat any confirmed mites or ringworm, and reduce stress with more play, predictable routines, and quiet hiding places. Because over-grooming is often a symptom of pain, sudden bald patches deserve a proper exam. If the hair loss spreads, does not regrow within a few weeks, or comes with itching, scabs, weight change, or appetite change, please consult your veterinarian.