Can dogs eat watermelon?

Why

There is nothing in watermelon flesh that is poisonous to dogs. It is mostly water, with a little natural sugar and some fibre, plus vitamins A, B6 and C and potassium. That water content is what makes it such a useful treat on a hot day — it is refreshing and filling without carrying much in the way of calories.

The risks with watermelon are mechanical rather than toxic. The hard black seeds don't break down properly, and if a dog swallows a good number of them — particularly a small dog with a narrow gut — they can clump and lodge in the intestine. A blockage is a surgical emergency, so it is simply not worth the gamble when flicking the seeds out takes seconds. The pale, soft seedlets in seedless varieties are immature and not a concern.

The rind is the bigger problem of the two. It is tough, fibrous and doesn't chew down well, so dogs tend to bolt chunks whole. Those chunks can sit in the stomach or gut and cause anything from a sore, vomiting tummy to a genuine obstruction. The hard green outer skin is worse again. Rind and skin go in the bin, not the bowl.

The other thing that catches people out is quantity. All that water and fibre arriving at once can loosen a dog's stools even though nothing harmful has happened. Dogs with diabetes, or those on a strict weight plan, should have the natural sugar factored in by your vet first — and anything watermelon-flavoured rather than actual watermelon (sweets, sugar-free jellies, flavoured drinks) is best avoided entirely, as sugar-free products may contain xylitol, which is dangerous to dogs.

How much is sensible?

Treat it as a treat, not a meal. The usual veterinary guideline is that treats of any kind should make up no more than about 10% of your dog's daily calories, and watermelon sits inside that budget easily — think a few bite-sized cubes for a Labrador, one or two small pieces for a terrier or a whippet, and less again for something toy-sized. Cut the flesh away from the rind entirely, pick out any hard black seeds, and chop it into pieces your dog can't inhale whole. Frozen cubes are a lovely summer option for a confident chewer, though go gently with puppies, seniors or dogs with dodgy teeth — chilled rather than rock-solid is kinder. Start with a small taste the first time and see how your dog's tummy handles it before making it a regular thing.

Signs to watch for

• Softer stools or outright diarrhoea within a few hours — the most common sign of simply having had too much
• Needing to wee more often than usual, because of the water content
• A gurgling, gassy tummy or a bit of mild bloating
• Being sick, especially if rind or a mouthful of seeds went down
• Off their food, unusually flat or restless, or repeatedly retching without bringing much up
• Straining to poo, or no poo at all, alongside a tender belly

If your dog has had too much

If your dog has just had a bit too much flesh and is only a little loose, that will usually settle on its own — keep fresh water down, skip the next treat, and let their tummy recover. Ring your vet if the diarrhoea or vomiting carries on beyond a day, if there is blood in it, or if your dog is very young, very old, small, or already unwell. If your dog has swallowed rind, skin or a mouthful of hard seeds, don't wait to see what happens — phone your vet, tell them your dog's size and roughly how much went down and when, and follow their advice. Repeated vomiting, refusing food, a painful or swollen belly, or straining with nothing coming out all mean your dog needs to be seen straight away rather than watched at home. Never try to make your dog vomit unless a vet has specifically told you to.

Serving tips

• Slice the melon, cut the flesh off the rind completely, then dice — never hand over a wedge and let your dog gnaw down to the green.
• Choose a seedless variety if you'd rather not pick seeds out; the soft pale seedlets in those are fine.
• Freeze small cubes in an ice cube tray for hot days, or blend the flesh and freeze it into a lick mat for a slower, cooler treat.
• Keep rind out of reach — bin scraps in a lidded bin and don't leave picnic plates or compost caddies where a hoovering nose can get at them.

Common questions