Why Is My Dog Vomiting? A Burlington Vet on When to Wait and When to Call

The call comes in a lot of mornings. A worried voice near Brant Street tells us the dog threw up on the kitchen floor once, ate breakfast anyway, and is now napping like nothing happened.

Then there’s the other call. Same symptom, very different story: the dog has been sick five times since lunch, won’t settle, and something feels off.

Both owners are asking the same thing. Should I wait and watch, or get in the car right now? We can’t diagnose your dog from a keyboard, but we can help you read the situation and know when picking up the phone is the right move.

Most single episodes of vomiting in a bright, playful dog are a passing stomach upset that settles on its own. According to the Merck Veterinary Manual, acute vomiting lasting less than 3 to 4 days with no other signs can often be managed by briefly withholding food while water stays available. Call us when it repeats or other signs appear.

If this is happening right now and your dog is vomiting repeatedly, retching with nothing coming up, bringing up blood, or you think they swallowed something toxic, don’t wait. Call us at (905) 336-4002. If you suspect a poison, call the Pet Poison Helpline at 855-764-7661 while you reach us. After hours, see our after-hours care page for the nearest emergency hospital.

Why is my dog throwing up but acting normal otherwise?

A dog who vomits once and then goes back to being playful, hungry, and comfortable is usually telling you it was a one-off. The Cornell Riney Canine Health Center notes that infrequent vomiting, such as after eating grass, is likely an isolated incident. The behaviour to watch is repetition, not the single mess on the floor.

Dogs get into things. A gulped meal, a bit of backyard grass, or a stolen scrap during a Burlington barbecue can all trigger one round of vomiting from a stomach that just wants to reset.

Bright eyes, a normal appetite at the next meal, and comfortable movement all point toward a minor upset rather than something deeper.

Cornell does add a caution worth holding onto: vomiting even once a week may point to an underlying disease. So a true one-off is fine to watch, but a pattern returning on a weekly rhythm deserves a look, and jotting down the date and time each episode gives us something we can use.

What’s the difference between vomiting and regurgitation in dogs?

They look similar on the floor but come from different places. The Merck Veterinary Manual describes vomiting as the forceful ejection of stomach contents driven by abdominal-muscle contractions. Cornell notes that regurgitation, by contrast, arrives with no warning and no retching, and may point to an esophageal problem rather than a stomach one.

This distinction changes what we go looking for. Vomiting has a build-up: you’ll often see drooling, lip-licking, a hunched posture, and heaving effort before anything comes up, and the material is usually partly digested.

Regurgitation is quieter. According to Cornell it comes with no retching and no warning, and the food is typically undigested, sometimes tube-shaped, often right after eating.

When you call, the detail we love to hear is exactly this: was there effort and heaving, or did it just fall out with no drama? A short phone video helps our team on Brant Street point the visit in the right direction.

When should I take my vomiting dog to the vet?

Certain signs move a case from “watch at home” to “call today.” The Cornell Riney Canine Health Center advises calling your vet if you notice lethargy, vomiting for more than 24 hours, a painful belly, or a fever. Cornell also flags blood in the vomit, or material with the look of coffee grounds, as a reason to book an appointment.

Blood is the clearest sign: Cornell notes that vomit with the consistency of coffee grounds, which is digested blood, warrants an appointment, and fresh red blood counts too. Per Cornell, vomiting past 24 hours, or with lethargy, a painful belly, or a fever, is a call-us situation.

The Merck Veterinary Manual draws a similar line from frequency: vomiting more often than once or twice daily, or with blood, abdominal pain, fever, or weight loss, is chronic and needs fuller investigation. Merck also warns that repeated vomiting can lead to weakness, lethargy, weight loss, dehydration, and electrolyte imbalance.

Some causes are outright emergencies. Merck describes hemorrhagic gastroenteritis as a sudden onset of vomiting and bloody diarrhea in previously healthy dogs, where fluid loss can lead to shock. A gastrointestinal obstruction is another; Merck notes it typically causes lethargy, loss of appetite, and vomiting a dog may be unable to stop, with surgery usually needed. Either is a same-day call, and after hours a trip to emergency. Our critical care page explains what those visits involve.

Why does my dog keep retching but nothing comes up?

Repeated trying-to-vomit with nothing produced is a sign we take seriously, especially in big dogs. The Cornell Riney Canine Health Center lists non-productive retching, attempting to vomit with no production, as a common sign of gastric dilatation-volvulus, also called GDV or bloat, which Cornell describes as life-threatening and requiring immediate medical and surgical care.

Bloat is one of the few dog emergencies where minutes genuinely matter. The picture is often unmistakable: a dog heaves over and over, may have a swelling or tight belly, paces, drools, and looks distressed, all without bringing anything up.

Cornell notes that GDV most affects large, deep-chested dogs, with older age and a nervous temperament as added risk factors. If you share your home with a big, barrel-chested breed, this is the scenario worth memorizing.

Not every unproductive gag is bloat; nausea, a tickly throat, or a bit of grass can cause dry heaving that passes. But because GDV moves so fast, our advice is simple: if your dog keeps retching with nothing coming up and seems distressed or bloated, treat it as an emergency and call us at (905) 336-4002, or head to the nearest emergency hospital after hours.

What common foods and household items make dogs vomit?

Some of the most frequent vomiting calls we field in Halton trace back to something the dog ate that it shouldn’t have. Several everyday kitchen items are genuinely toxic to dogs, and vomiting is often the first sign.

Warm-weather season in Burlington brings more of these into play, from backyard grapevines to a purse with sugar-free gum left within reach. Here’s a quick reference on the common household toxins, drawn from the poison-control authorities:

A toxin exposure is not a wait-and-see situation. If you know or suspect your dog ate any of these, call us at (905) 336-4002, or reach the Pet Poison Helpline at 855-764-7661 or the ASPCA Animal Poison Control Center at (888) 426-4435, before symptoms even start. Keeping human treats up high and garbage secured, especially around holidays and Ontario’s backyard-BBQ months, prevents most of these calls.

What can I give my dog to settle its stomach at home?

For a mild, isolated case in a dog who’s otherwise well, gentle home care is reasonable. The Cornell Riney Canine Health Center suggests an isolated case may settle if you withhold food, but not water, for 12 hours, then feed plain white rice and boiled chicken for two days. The Merck Veterinary Manual describes a similar brief food rest for acute cases.

The key word in both is mild. This is for the one-off, bright, comfortable dog, not the one ticking any of the warning boxes above.

On water, both sources point the same way. Merck stresses that water should never be withheld unless your dog is receiving supplemental fluids from a vet, so the rest is for food, not hydration.

A bland reset means small, plain portions. Cornell’s white rice and boiled chicken, offered in modest amounts with no seasoning, give the gut something easy while it recovers. Our nutrition and weight management page covers transitioning food gently.

Skip the human medicine cabinet, since many over-the-counter stomach remedies made for people aren’t safe to give a dog. Puppies are the exception: because vomiting can be an early sign of serious infection in young dogs, we’d rather see them sooner, and keeping their vaccinations current is part of why, as our wellness and vaccinations page explains.

This article is educational and isn’t veterinary advice or a substitute for an exam. If you’re worried about your pet right now, call us at (905) 336-4002 or your nearest emergency veterinary hospital.

We know how unsettling it is to watch your dog be sick and not know whether it’s nothing or something. When you’re not sure which side of the line you’re on, that’s what we’re here for, and a quick call to our team on Brant Street costs you nothing but a few minutes.

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Frequently asked questions

Is my dog throwing up blood an emergency?

Blood in vomit is always a call-us sign. The Cornell Riney Canine Health Center says to make a veterinary appointment if you see blood, or material with the consistency of coffee grounds, which is digested blood. The Merck Veterinary Manual also links sudden vomiting with bloody diarrhea to hemorrhagic gastroenteritis, where fluid loss can cause shock. Don’t wait on this one.

Should I withhold food and water when my dog is vomiting?

Food and water are treated differently. The Merck Veterinary Manual describes briefly withholding food for a mild acute case, but stresses that water should never be withheld unless your dog is getting supplemental fluids from a vet. So the short food rest can make sense at home, while hydration stays available. When in doubt, call us first.

Can vomiting be more serious in puppies?

Yes, and we set a lower threshold for young dogs. The Cornell College of Veterinary Medicine advises that any puppy or unvaccinated dog with vomiting and diarrhea should be tested for parvovirus, a serious infection whose fluid losses often require intravenous fluids in hospital. If a Burlington puppy is vomiting, please call us rather than waiting it out.

My dog ate grass and then vomited. Is that a problem?

Usually not on its own. The Cornell Riney Canine Health Center notes that infrequent vomiting, such as after eating grass, is likely an isolated incident. A dog who grazes, brings up a little, and then carries on normally is typically fine. Cornell does add that vomiting even once a week may signal an underlying issue, so watch for a pattern.

Which dogs are most at risk of bloat?

The Cornell Riney Canine Health Center reports that gastric dilatation-volvulus, or bloat, most affects large, deep-chested dogs, with older age and a nervous temperament as added risk factors. If you own a big, barrel-chested breed, learn the sign of non-productive retching, because Cornell notes GDV is life-threatening and needs immediate medical and surgical care.

Sources

Merck Veterinary Manual

1. Merck Veterinary Manual (Pet Owner Version). “Vomiting in Dogs.” https://www.merckvetmanual.com/dog-owners/digestive-disorders-of-dogs/vomiting-in-dogs
2. Merck Veterinary Manual (Pet Owner Version). “Disorders of the Stomach and Intestines in Dogs.” https://www.merckvetmanual.com/dog-owners/digestive-disorders-of-dogs/disorders-of-the-stomach-and-intestines-in-dogs

Cornell University

1. Cornell University Riney Canine Health Center. “Vomiting.” https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/vomiting
2. Cornell University Riney Canine Health Center. “Gastric Dilatation-Volvulus (GDV) or Bloat.” https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/gastric-dilatation-volvulus-gdv-or-bloat
3. Cornell University College of Veterinary Medicine. “Parvovirus: Transmission and Treatment.” https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/parvovirus-transmission-treatment

Pet Poison Helpline

1. Pet Poison Helpline. “Poison-Proof Your Home: Kitchen.” https://www.petpoisonhelpline.com/pet-owners/poison-proof-your-home/kitchen/

ASPCA Animal Poison Control Center

1. ASPCA Animal Poison Control Center. “People Foods to Avoid Feeding Your Pets.” https://www.aspca.org/pet-care/animal-poison-control/people-foods-avoid-feeding-your-pets