Why Is My Dog Vomiting? A Pet Parent’s Guide to What It Could Mean

Most dogs vomit occasionally. But if it’s happening often or seems more serious, it’s time to pay attention.

Watch for these red flags:

• Blood in the vomit (bright red or dark like coffee grounds)
• Vomiting more than once or twice in a 24-hour period
• Lethargy, weakness, or signs your dog isn’t feeling right
• Refusing food or water
• Signs of dehydration like dry gums or sunken eyes
• Fever, bloated abdomen, or signs of pain when touched
• Vomiting in puppies, senior dogs, or pets with underlying health issues

When in doubt, call your vet. Trust your instincts: you know your dog best.

These two can look similar but mean different things — and telling your vet which one it is makes a big difference.

• Vomiting is active: your dog heaves, retches, and brings up food, bile, or foam from the stomach.
• Regurgitation is passive: food comes back up suddenly, often undigested and tube-shaped, without effort or warning.

Why it matters: Describing the right one helps your vet narrow down possible causes and choose the right tests faster.

How often and for how long your dog vomits can tell you a lot about what’s going on.

• Acute vomiting = sudden and short-lived. Often linked to eating something unusual, stress, or a mild infection. May settle with basic care.
• Chronic vomiting = happens regularly or over weeks/months. Can be mild (like morning bile) or linked to bigger issues such as food intolerance, reflux, or organ disease.

Why it matters: Tracking the pattern, like frequency, timing, and what the vomit looks like, gives your vet critical clues to find the cause.

Vomiting is a symptom, not a diagnosis. Here are the most common reasons dogs throw up:

Dietary Indiscretion

The classic case of a dog eating something they shouldn't — leftovers, rubbish off the floor, grass, or a toy. Usually not serious, but sometimes it can cause a blockage or infection.

Eating Too Fast

Some dogs inhale their food so quickly it comes right back up. Slower feeder bowls can help prevent this.

Food Allergies or Intolerances

Certain ingredients can irritate your dog’s digestive system. Vomiting may be paired with itchy skin in your dog, ear infections, or dog diarrhoea.

Infections and Parasites

Viruses like parvo or bacterial infections can cause vomiting, especially in puppies. Intestinal worms are another common cause, which can be managed with dog worming treatments.

Toxins and Poisons

Chocolate, grapes, xylitol, medications, and some household plants can all cause vomiting — sometimes dangerously. Always treat suspected ingestion of toxins as an emergency.

Medical Conditions

More serious, ongoing vomiting may be linked to:

• Pancreatitis
• Kidney or liver disease
• Inflammatory bowel disease (IBD)
• Ulcers
• Cancer

Not every cause is preventable — and it’s not a reflection of poor care. Dogs are curious, and some conditions develop regardless of diet or routine.

The colour and content of your dog’s vomit can offer helpful clues, but they aren’t a diagnosis on their own. Still, describing what you see can give your vet valuable information.

Here’s a quick-reference guide:

These are clues — not answers. Even bright yellow or green vomit doesn’t always mean something is wrong. But if it’s happening repeatedly or with other symptoms, speak to your vet.

If your dog vomits once but seems otherwise normal, simple home care may be enough. Here’s what you can try, and the warning signs that mean it’s time to call your vet.

Safe home remedies for mild, one-time vomiting

• Rest the stomach: Withhold food for 6–12 hours (not suitable for puppies or toy breeds at risk of low blood sugar).
• Hydration matters: Offer small sips of water or ice cubes to prevent dehydration.
• Bland diet trial: Feed plain cooked chicken (no skin or bones) and white rice in small amounts.
• Ease back slowly: Continue small meals for 1–2 days, then transition back to regular food if vomiting doesn’t return.

When not to treat dog vomiting at home

Call your vet right away if:

• Vomiting is repeated or lasts more than 24 hours.
• Your dog refuses all food and water.
• You see blood, brown, or black vomit.
• They are a puppy, senior, or have a known health condition.
• They show worrying signs such as lethargy, bloating, or obvious pain.

Don’t wait it out. Early veterinary care usually means faster recovery and fewer risks.

Not every case of vomiting can be prevented, but small changes can reduce and manage how often it happens and make episodes easier to manage.

Keep your dog’s diet consistent

Sudden food changes are one of the most common causes of dog vomiting. Transition to new foods gradually over 7–10 days. Avoid fatty leftovers or rich treats that can upset the stomach.

Slow down fast eaters

Dogs that throw up right after eating often eat too quickly. Slow-feeder bowls, food puzzles like a KONG Dog Wobbler, or feeding smaller meals more often can help prevent vomiting after meals.

Watch out for common vomiting triggers in your dog

Keep rubbish bins secure, supervise yard time, and block access to toxic foods and plants (like chocolate, grapes, or lilies) that can cause dangerous vomiting episodes.

Support your dog’s sensitive stomach

For dogs with recurring morning bile or upset stomachs, bland diets (boiled chicken and rice), prescription sensitive stomach dog food, or probiotics may help. Ask your vet about the best diet for sensitive stomachs or food allergies.

Watch for travel and motion sickness in your dog

If your dog vomits in the car, keep them on an empty stomach before trips, provide fresh air, and speak to your vet about anti-nausea medication if needed.

Chronic vomiting and underlying dog health issues

If your dog vomits regularly, it could signal reflux, inflammatory bowel disease (IBD), pancreatitis, kidney disease, or liver problems. These cases usually need more than home care. Vets may use blood tests, imaging, or diet trials to find the cause, then manage it with tailored treatments.

Ensure your dog is properly hydrated

Keep your dog hydrated by always keeping fresh water available. For repeated vomiting or signs of dehydration (sunken eyes, dry gums), seek veterinary care promptly.

If your dog needs veterinary care, providing accurate information helps guide testing and treatment. Here's what to track:

• When the vomiting started and how often it's happening
• What the vomit looks like (colour, texture, contents)
• What your dog ate in the past 24–48 hours
• Any changes in behaviour — energy, appetite, thirst, bathroom habits
• Other symptoms — diarrhea, coughing, gagging, pacing, signs of pain
• Recent exposures — new food, treats, medications, access to garbage or toxins

Photos or videos can be very helpful. If you can safely capture what you're seeing, bring it with you or show your vet.

Being prepared doesn’t mean assuming the worst — it simply helps your vet make the best call, faster.

Sometimes vomiting is part of a bigger issue. Here’s a clear list of signs that suggest your dog needs veterinary attention right away:

• Blood in the vomit
• Vomiting that continues for more than 24 hours
• Refusing food and water
• Signs of dehydration (dry gums, sunken eyes, skin that doesn’t bounce back)
• Lethargy or unusual quietness
• Bloated abdomen
• Signs of abdominal pain or restlessness
• Recent ingestion of potential toxins or foreign objects
• Vomiting along with diarrhea, especially in puppies or seniors

Your instinct as a pet parent matters. If something feels off — even if your dog’s symptoms seem mild — call your vet. You’re not overreacting. You’re being responsible.

Is it normal for my dog to eat grass and then vomit?
Yes, this is common. Some dogs eat grass to help clear their stomach or trigger vomiting. It’s usually not a concern unless it becomes frequent or leads to persistent vomiting.

Why is my dog vomiting yellow bile?
Yellow bile often appears when a dog’s stomach is empty for too long. It may be related to acid buildup, hunger nausea, or a mild digestive upset. Frequent bile vomiting could point to reflux, food intolerance, or an underlying issue — check with your vet if it’s happening regularly.

Can stress or anxiety cause vomiting?
Yes. Dogs under stress may vomit, especially if they’re prone to nervous stomachs. Vomiting caused by separation anxiety, travel, or big changes in routine is typically short-lived — but should still be monitored.

What’s the difference between vomiting and coughing up foam?
Vomiting is from the stomach and usually includes effort and substance. Coughing up white foam often points to respiratory or throat irritation, kennel cough, or tracheal collapse. If you’re unsure which one it is, take a video and consult your vet.

Can switching foods cause vomiting?
Yes, especially if the change is sudden. Transitioning to a new food should be done gradually over 7–10 days. Abrupt changes can upset your dog’s digestion.

Vomiting in dogs can be harmless — or it can signal something that needs attention. The key is to look at the full picture: how often it’s happening, how your dog is acting, and what else is going on.

If you're ever unsure, speak to your vet. You’re not overreacting — you’re being proactive.

Your care and vigilance matter. Noticing small signs, keeping track of patterns, and asking the right questions make a big difference in your dog’s health and recovery. You're doing the right thing by paying attention.

This article was written by Dr Jack Ayerbe