Why is my cat’s coat suddenly dull?

A sudden change in coat quality is information. The most common causes: diet (a recent food switch to lower-quality food, or a longstanding diet that’s been borderline), dehydration (not enough water through food and bowl), age (senior cats often groom less and the coat reflects it), parasites (fleas, mites), and underlying illness. Cornell flags coat changes as one of the earliest visible signs of systemic disease, since the skin is metabolically active and responds quickly to imbalances. If the change is recent and the diet hasn’t changed, that’s a vet conversation.

When to call a vet: sudden coat dullness, especially with weight loss, appetite changes, lethargy or any behavior change, deserves a vet visit.