Diabetic dog vomiting: when it's an emergency, and what to do about insulin

My diabetic dog is throwing up. What do I do?

Call your vet. Plenty of dogs throw up now and then and are fine, but a dog on insulin is different, because his food and his insulin are planned together. If the food doesn't stay in, the plan doesn't fit any more.

Before you call, check three things: has he had his insulin yet, did his last meal stay down, and how does he seem now? Is he alert and himself, or quiet, weak or off his food?

If he's weak, won't eat, keeps vomiting, is breathing fast or heavily, or his breath smells sweet, call your vet or an emergency clinic now. The emergency page has what to tell them, and no emergency vet nearby helps if your clinic is closed.

If he vomited once and seems himself, still call before his next insulin. Your vet knows his plan and will tell you what to do with the next meal and the next shot.

Either way, don't give extra insulin, and don't decide on the insulin by yourself.

Should I give insulin if my diabetic dog vomited?

Not without your vet's say. Insulin lowers blood sugar, and it's meant to work on the food he has just eaten. That's why vets usually ask you to feed him first and give the shot after he has eaten. If his meal came back up, there may be nothing for the insulin to work on.

If he vomits before his shot, wait and call your vet before you give anything. Do I feed my diabetic dog before the insulin? explains why the meal usually comes first.

If he vomits after his shot, call your vet now and tell them when the insulin went in and when he was sick. Watch him closely for weakness, wobbling or trembling, because his sugar could drop. Low blood sugar in dogs has the signs and what to do.

If you're not sure whether he got his insulin at all, don't give another to be safe. What if we might have given the insulin twice? covers that.

The two things to avoid: giving his usual shot when his food didn't stay down, and giving extra insulin to make up for a sick day. Both can go wrong fast.

When vomiting is an emergency

The emergency to know about is diabetic ketoacidosis, often called DKA. It happens when there isn't enough insulin working: his body breaks down fat for fuel instead, and acids called ketones build up in his blood. It's life-threatening, and it can happen in a dog who is already on insulin.

The signs often come together: vomiting, not eating, being very tired, weak or low, breathing fast, deep or with effort, and breath that smells sweet. He may also drink and pee even more than usual. Any of these with vomiting is a reason to call your vet now, day or night.

There is no safe way to treat ketoacidosis at home. It's a medical emergency that needs treatment in hospital, and searching for home remedies wastes time he may not have.

Other signs that mean go now, with or without ketoacidosis: blood in the vomit, a sore or swollen belly, vomiting again and again, not keeping water down, a fever, or a dog who is flat and hard to rouse.

If you have urine strips at home, a strip that shows ketones is a reason to call straight away. But a dog who is vomiting and unwell needs the vet whatever the strip says. High blood sugar in dogs explains how an everyday high differs from this emergency.

Why a diabetic dog vomits

Diabetic dogs throw up for the same reasons other dogs do, but the reason matters more, because some causes upset his diabetes too.

Something he ate. Scraps, rubbish from the bin, a new food or treat, or something he found on a walk. My dog ate something he shouldn't. What now? covers what to do.

Pancreatitis. An inflamed pancreas is common in diabetic dogs. It can cause vomiting, belly pain and refusing food, and it can unsettle diabetes that was well controlled. Food after pancreatitis explains how it changes his meals.

Ketoacidosis. Vomiting can be one of its first signs, which is why vomiting in a diabetic dog always gets a call.

Another illness. Kidney or liver problems and other illnesses can cause vomiting, and infections and other illnesses can also make insulin work less well. Diabetes alongside serious illness has more.

It's worth telling your vet if he brought food up without effort, with no heaving. That's often regurgitation rather than vomiting, and the causes are different.

Diabetic dog vomiting water or undigested food

A diabetic dog whose sugar runs high drinks a lot, and a dog who gulps a lot of water can bring it straight back up. If that happens once and he's otherwise himself, mention it when you call your vet. If he can't keep water down, call now: he can't make up the water he loses.

Bringing up undigested food soon after a meal means the meal didn't stay in, and that matters for his insulin. Treat it like any other vomit: call your vet before his next shot.

Vomiting and lots of peeing together can dry a dog out quickly. Signs of dehydration goes through what to look for, and diarrhoea and diabetes covers an upset stomach at the other end.

Keep fresh water out unless your vet tells you otherwise. Taking water away from a vomiting dog can make dehydration worse.

What not to do at home

Don't give extra insulin, and don't give his usual shot to a dog who hasn't kept his food down, unless your vet says so.

Don't start fasting him on your own. The usual advice for an upset stomach is to rest it without food for a while, but a dog on insulin needs his food and insulin planned together, so let your vet decide.

Don't give medicines from your own cupboard for nausea or an upset stomach. Your vet can prescribe something that's safe for him if he needs it.

Don't wait overnight to see if he's better. If he's still sick, not eating or not himself, that's another call to the vet. My diabetic dog won't eat and he ate only part of the meal cover the days when food is the problem.

What to tell your vet

Your vet will ask the same few questions, so jot them down before you call: when he was sick and how often, what came up (food, water, foam or yellow liquid, any blood), when he last ate and how much, when he last had insulin and whether you're sure it went in, how much he's drinking and peeing, and how he seems now.

Take his insulin and your notes with you if you go in. Home testing, glucose curves and notes for your vet has a simple way to keep notes, and when the day goes wrong has the other urgent problems in one place.