Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

What Causes Dogs to Collapse After Vomiting? Our Vet Explains 5 Possible Causes

Senior Basset Hound collapsed on the ground

Vomiting is one of the most common reasons that dogs attend the vet clinic. As a vet, I expect to see at least one dog for vomiting every day that I see consults. Most of the time, vomiting is caused by dogs eating something they shouldn’t, and their stomach subsequently trying to get rid of the problem.

However, some dogs will present in a much worse condition. A dog that has collapsed after vomiting is treated as an emergency (as is any collapsed dog). There are five main causes of collapse after vomiting, and each will be discussed below.

divider single dog paw oct 2024

The 5 Possible Causes of Why Dogs Collapse After Vomiting

1. Anaphylaxis

Bee stings sometimes cause hives and facial swelling in dogs, but they can also cause anaphylaxis. Anaphylaxis is a severe allergic reaction. When this occurs, the dog’s immune system has recognized something as foreign and has a severe, “over-the-top” reaction to it.

These are sometimes also referred to as hypersensitivity reactions. Common offenders include insect and bee stings, though contact allergies and injection reactions can also cause anaphylaxis. These dogs will often vomit initially, which might be considered a “warning sign.”

As the inflammatory response progresses, dogs collapse and exhibit labored breathing. Immediate veterinary intervention is warranted, as anaphylaxis is life-threatening if left untreated.

Dog with anaphylactic reaction
Image Credit: Todorean-Gabriel, Shutterstock

2. Acute Hemorrhagic Diarrhea Syndrome

This syndrome is relatively common in dogs 1. It’s a long name for a condition that isn’t extremely well understood: “acute” for sudden onset, “hemorrhagic” for bloody, and “diarrhea” for loose stools.  It may be triggered by dogs eating something strange, or a certain bacterium, but neither has been proven.

Either way, dogs initially show vomiting and bloody diarrhea. This condition can progress rapidly, causing shock. Dogs that are in shock are very weak and sometimes collapse. If you notice vomiting or bloody diarrhea, seek prompt veterinary care.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the personalized advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content Savings V1


3. Seizures

Yes, vomiting can precede seizures. The “prodromal” period refers to the time between the initial signs and the actual seizure event. Dogs may show unusual behaviors, lethargy, and vomiting. Seizures then occur and are usually very confronting for owners to see.

While seizing dogs will collapse, and they will also show other signs too: rigid legs, muscle tremoring, foaming at the mouth, urinating, and defecating. There are a number of causes of seizures in dogs, ranging from toxins and infections to epilepsy and brain tumors.

old dog having seizures
Image Credit: Kittima05, Shutterstock

4. Bloat

Bloat is a scary and life-threatening disease of large and giant breed dogs. It may also be referred to as a “twisted stomach” or, in the veterinary world, “GDV” (gastric dilation and volvulus). Early on in this disease, dogs will vomit or retch without producing anything.

Within minutes they can collapse, as the stomach has twisted on itself and cut off its own blood supply. The abdomen appears bloated as the stomach distends with gas. Immediate veterinary treatment (including surgery) is necessary.


5. Vagal Response

This is the most benign (or least concerning) cause of collapse after vomiting, though it will still scare any dog owner. The vagus nerve sends impulses that slow the heart and aid digestion—think of it as the main driver of “rest and digest”.

Occasionally, as dogs vomit due to gut upset, the vagus nerve becomes stimulated, and the dog will fall over after vomiting. Thankfully, dogs will usually recover very quickly.

longhaired Dachshund dog coughing
Image Credit: Eric Isselee, Shutterstock

divider single dog paw oct 2024

In Conclusion

It is important to note that many other diseases can cause vomiting followed by collapse in dogs; the above list outlines five common causes only. Heart disease, poisoning, heat stroke, and cancer can also lead to vomiting followed by collapse.

Whatever the cause, if you’ve noticed your dog vomiting, or collapsed, do not hesitate to seek veterinary care. This gives your pet the best chance of prompt treatment and recovery.


Featured Image Credit: McGraw, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

6 DIY Dog Hats You Can Make at Home (With Pictures)

Hats designed for dogs immediately add a boost of cuteness to your adorable pup. You can find all kinds of dog hats, and...

My Senior Dog Is Panting & Shaking, What’s Wrong? (Vet Answer)

As a veterinarian, getting to the bottom of excessive shaking and panting in senior dogs can be difficult. As the owner of a...

Do Dogs Have Taste Buds? Canine Tasting Facts

Being able to taste and discern between different foods is a sense that’s invaluable to humans. If you’re a dog owner, you might...

Can a Dog’s Nose Sense Heat? What Science Has to Say

We already know that a dog’s nose is a powerful tool. Humans have utilized the canine’s keen sense of smell to track down...

More related

Waggle Pet Monitor Pro+ Review 2025: An Expert’s Breakdown

Have you ever rushed through the grocery store because you left your pet in the car on a sunny day? Or taken your...

Why Is My Dog Dragging Their Butt? Vet-Verified Scooting Explanation & Remedies

Some aspects of pet ownership aren’t pleasant. After all, the good comes with the bad. Dogs scooting their butts is an example of...

11 Best Grain-Free Puppy Foods in 2025: Reviews & Top Picks

To help your puppy get the best possible start in life, you must feed them an appropriate diet. Puppies grow incredibly quickly compared...

Alopekis Dog Breed: Info, Pictures, Care Guide & Traits

The Alopekis is a great breed for just about any family. They are small in size, only bark occasionally, and are adaptable to...

Keep reading

Can Dogs Eat Pears? Vet-Approved Facts & FAQ

It’s natural to wonder what foods are safe for your dog to consume, as it’s common to want to toss them a quick piece of meat or veggies while you’re at the dinner table. But what about fruit? More specifically,...

Can Dogs Eat Pears

What Is DHA in Dog Food? Vet-Reviewed Benefits, Drawbacks & FAQ

DHA is an omega-3 fatty acid that is found in fish oil. It is a popular ingredient in dog food because it is thought to have many health benefits. These include reducing inflammation, improving heart health, and aiding in cognitive...

dog eating dog food

Can Dogs Eat Dried Apricots? Vet-Verified Nutrition Facts & Info

Our dogs are omnivorous creatures—just like us. That means they could enjoy a wide selection of meat, fruits, veggies, and grains! If you’ve been looking for a few different options, other than boring dog treats to get your dog’s appetite...

Dogster-Can-Dogs-Eat-Dried Apricot

5 Best Dog Foods for Bernedoodles in 2025 – Reviews & Top Picks

If you’re lucky enough to be the pet parent of an adorable Bernedoodle (also known as Bernese Mountain Poo, Bernesepoo, or Bernepoo), it’s only fitting that you’re looking to feed them the best dog food available. Your loving and loyal...

Bernedoodle Puppy lying on the ground

Puppy Feeding Guide: Quantity, Schedule & FAQ

It is essential to feed your puppy correctly. Puppies are constantly growing and need different nutrition than an adult dog. Feeding your puppy correctly now can prevent problems later on. For instance, many large and giant dogs will develop hip...

Cocker Spaniel puppy eating

Can Dogs Eat Goat Meat? Vet-Approved Facts & FAQ

Dogs are facultative carnivores, meaning they can be quite adaptable when it comes to food. Although their ancestors evolved to eat a primarily carnivorous diet, dogs can do well on diets that have a lot of, a little of, or...

Can Dogs Eat Goat Meat

7 Best Dog Foods for Corgis in 2025 – Reviews & Top Picks

If you’re the pleased and proud owner of a Corgi, you’re a lucky person indeed! Corgis are adorable but also bundles of energy and personality with a fascinating history. Whether you have a Pembroke or a Cardigan, both Corgi breeds...

Portrait of adorable Corgi

How to Switch Your Dog’s Food: 6 Vet-Approved Steps

When we choose a dog food, we might not consider that our dog won’t be a match for one reason or another. Or perhaps you haven’t had the results with the dog food that you are currently on and want...

fluffy dog eating dry kibble from elevated bowl