Raisins — Food safety facts
Do not feed · Cats · full breakdown on the linked food page
Toxic, like grapes — a small amount can cause acute kidney failure. Even one raisin for a small dog deserves a vet call.
Short answer
Yes, raisins are toxic to cats and can trigger acute kidney failure, so you need immediate veterinary attention. Even a single raisin can cause serious damage because the toxin affects the kidneys quickly. Watch for vomiting, lethargy, loss of appetite, or increased thirst, but do not wait for signs to appear. Call your veterinarian or the ASPCA Animal Poison Control Center at 888‑426‑4435 right away.