Watermelon — Food safety facts
Safe to share · Cats · full breakdown on the linked food page
Safe seedless flesh in pieces. Remove all seeds and the rind (choking/blockage risk).
Dogs and cats carry the same rating (Safe to share), so the notes below hold for either pet.
Watermelon is not toxic to cats. The real limit is calories, fat and salt, so treat it as a small extra alongside the normal ration rather than a meal in itself.
There is no poisoning risk here, and the usual problem is simply eating too much at once: a heavy fat or salt load can bring on loose stools or a single vomit. Offer water, keep an eye on the pet for 24 hours, and do not induce vomiting.
Why these cautions matter
Stone-fruit pits and some seeds release cyanide when crushed, and quite apart from that they are a choking and blockage hazard.
Watermelon can stay on the rotation, but only as an extra mouthful: keep the rest of the day's food unchanged and watch the litter box and how quickly they finish the next meal.
The full verdict, portion guidance and serving notes are collected on the Watermelon food facts page.