My diabetic dog won't eat: what to do about the insulin

First: don't guess, call your vet

It's insulin time, the bowl is still full, and your dog has walked away. This is one of the most common worries owners of diabetic dogs have, and it's worth knowing what to do before it happens.

Insulin is meant to go with a meal. It helps the body use the sugar from food, so with many insulins, when there's no food, blood sugar can fall too low. Some longer-acting insulins are planned differently, and only your vet knows which yours is.

That's why the safest first step is simple: if your diabetic dog isn't eating, call your vet before you give the insulin. They know your dog, the insulin and the plan, and they can tell you what to do this time.

Unless your vet has already written down what to do, don't give the insulin, and don't make up a smaller amount. Call your vet. If you can't reach them, call an emergency vet. How much insulin to give is always your vet's call.

If you've already given the insulin and your dog won't eat, or brings the food back up, call your vet or an emergency vet now, and don't give any more. Vomiting in diabetic dogs explains why it matters.

Why one skipped meal matters with insulin

Think of insulin and food as a pair. The insulin is measured for a dog who eats their normal meal. Take away the meal, and the same insulin can bring blood sugar down further than it should.

Sugar running too low can come on fast and make a dog wobbly, dazed or worse. Low blood sugar in dogs explains the signs and what to do.

Vets often say that, for a short while, sugar running a little high is less dangerous than sugar running too low. That's why the decision about the insulin on a no-eating day belongs with your vet, not with a guess.

Why advice online doesn't match, and why yours should come from your vet

If you search this question, you'll find pages that say different things. Even respected vet sites don't all give the same answer. That isn't because one of them is careless. It's because the right plan depends on the dog: which insulin they're on, how settled their diabetes is, and what else is going on with their health.

So the best time to ask is now, on a good day. At your next visit or phone call, ask your vet: "If my dog won't eat, or only eats part of the meal, what do you want me to do about the insulin?" Write the answer down and put it on the fridge.

A meal that's only half eaten counts too. My diabetic dog ate only part of the meal covers that, and it's another thing to ask your vet about in advance.

And if your dog seems unwell as well as not eating, don't just carry on as normal. Tell your vet. If you check glucose at home, write the reading down and tell your vet, but don't choose the insulin from that number. If a urine strip shows ketones, call now.

Go now or phone today: the signs

Call your vet now, or an emergency vet if yours is closed, if not eating comes with any of these: vomiting, diarrhoea, weakness, a wobbly walk, unusual tiredness, fast breathing, not drinking, or breath that smells sweet, like nail-polish remover. If your dog collapses, go to the emergency vet and ring on the way.

Those can be signs of diabetic ketoacidosis, a life-threatening complication of diabetes. Diabetic ketoacidosis in dogs explains why it can't wait.

Signs that sugar has gone too low, such as wobbliness, a dazed or vacant look, twitching or collapse, also need help straight away. The emergency page lists them all in one place.

If your dog is bright, drinking normally and just turned their nose up at one meal, it still needs a phone call to your vet today, before the insulin.

Why diabetic dogs go off their food

In any dog, refusing food is often a sign of illness, and in a diabetic dog it's worth taking seriously early, not after a few days.

Some of the reasons vets look for: ketoacidosis, which often follows another illness such as pancreatitis or an infection; pancreatitis itself, which commonly brings nausea, vomiting, belly pain and a poor appetite; a painful tooth or a sore mouth that makes eating hard; an upset stomach; or another illness altogether.

Sometimes it really is a fussy day, a new food, a hot afternoon or a stressful change at home. But that's for your vet to decide once the serious reasons are ruled out. Vomiting in diabetic dogs and food when a dog has diabetes and pancreatitis go into two of the common ones.

If chewing seems to be the problem, what a senior diabetic dog with bad teeth can eat may help, once your vet has had a look.

Gentle ways to tempt a reluctant eater, with your vet's OK

If your vet says your dog is otherwise well, a few gentle things can help. Some dogs eat better from your hand, so try hand-feeding if your dog responds to the attention. Is it all right to hand-feed a diabetic dog? has more.

Offer the meal somewhere quiet, away from other pets, and give your dog a little time.

Check any topper with your vet first. Something that seems harmless can change how the meal and the insulin fit together.

Don't switch foods on your own. Diabetic dogs do best on the same food, at the same times, every day, and a sudden change can make things harder. Should I keep my diabetic dog on the same food? explains why.

What to say when you call the vet

Have this ready so the call is quick and clear: what your dog ate and when; whether any of the meal was eaten; when the last insulin was given; any vomiting, diarrhoea or drinking changes; how lively your dog is; and anything unusual, like a strange smell on the breath.

Ask your vet to tell you clearly what to do about this insulin, when to feed again, and what would mean bringing your dog in.

Then make the plan for next time. Write it on a card for the fridge: "If my dog won't eat, my vet says: ... Our vet's number: ... Emergency vet: ..." The questions for the vet sheet and the "Insulin given?" fridge card sit well beside it.