Why Your Dog Is Throwing Up Blood

Why Your Dog Is Throwing Up Blood

Why Your Dog Is Throwing Up Blood | Innovet Pet

It's not uncommon for dogs to throw up for a variety of reasons. Sometimes they've just switched to a new food, other times they may have eaten something they shouldn't have, and occasionally they get sick, just like we do. So long as the vomiting isn't a recurring issue, it's usually nothing to worry about.

However, there are instances where you may find your furry friend throwing up blood, or having blood mixed in with their vomit. This is much less common, and generally much more serious. If you do notice that your dog is throwing up blood, the first thing you should do is consult with your vet. They will know how to best handle the situation, diagnose the root of the problem, and get your dog back in tip-top health.

In the meantime, though, here are some of the most common reasons dogs vomit blood, what symptoms to look for, and how to keep your pet safe.


1. Why Is My Dog Throwing Up Blood?
2. What To Look For When Your Dog Is Vomiting Blood
3. Causes of Dogs Vomiting Blood
4. What To Do If Your Dog Is Throwing Up Blood
5. How To Determine The Cause of Blood In Your Dog's Vomit
6. Diagnosis and Tests For Dogs Vomiting Blood
7. Treatment For Blood In Dog's Throw Up
8. Conclusion

Why Is My Dog Throwing Up Blood?

The term for throwing up blood is hematemesis, and it almost always indicates that something serious is wrong with your dog. The exact severity of the issue depends on how much blood they are expelling and how frequently. There are many causes behind hematemesis, however, so it is difficult to give a simple answer as to why it's affecting your dog and how to treat it.

One cause of hematemesis could be an issue with your dog's digestive system. A disruption in their esophagus (the tube connecting their stomach to their mouth), irritation in their bowels or stomach, or intestinal inflammation. These problems can lead to bleeding, which your pet's body will then rid itself of through vomiting. The blood could also originate from another part of their body, like their lungs or mouth, and enter their digestive system that way. Hematemesis can also be caused by the ingestion of foreign objects, a medication overdose, or internal injury.

As mentioned previously, if your dog is throwing up a substantial amount of blood, don't hesitate to take them to the vet. It's a difficult issue to treat and diagnose at home, and the consequences of not seeking medical attention for your dog could be fatal.

What To Look For When Your Dog Is Vomiting Blood

The most important thing to look for when your dog is throwing up blood is the color and consistency of the blood. If it's a bright red and makes up the majority of your dog's vomit, then they are likely bleeding a large amount. This should be treated as a medical emergency and treated as soon as possible.

If the blood is dark brown or red and has a consistency resembling coffee grounds, it means that the bleeding has likely been going on for a while. The reason it looks like that is because it has been sitting in their digestive system. This is equally concerning and should also be treated as a serious emergency.

The blood could also look like a small number of partial clots, which is less serious initially. This is often the result of stomach irritation and could go away on its own. If the blood in your dog's throw up looks like clots, pay very close attention for anymore vomiting, and if they continue to throw up, then you should take them to a vet to have the issue diagnosed.

Often times, dogs that are vomiting blood will also have blood in their stool. They may also develop a fever, diarrhea, shock, loss of appetite, lethargy, stomach pain, and a black, tar-like stool. Any signs of sickness that are concurrent with your dog's hematemesis most likely mean that the issue won't go away on its own and medical attention is required. When assessing your dog's condition, look for bleeding around their mouth and nose, and check for any bruising.

Causes of Dogs Vomiting Blood

Because there are so many potential causes for blood in your dog's vomit, diagnosing it without a vet's help can be difficult. The source of the issue can range from a minor problem that will resolve itself to a serious, life-threatening issue that needs to be treated immediately. For this reason, it is recommended that you take your dog to the vet as soon as you notice the issue so that, in the unfortunate circumstance that it is serious, you don't lose any necessary time.

If there is only a small amount of undigested blood in your dog's vomit, or if you can find a cut on or around their mouth, then your dog is most likely safe but should be monitored closely to make sure the problem doesn't escalate. If it does escalate, then vet intervention should be sought quickly.

Ingesting Foreign Objects

The most common cause for your dog vomiting blood is the ingestion of a foreign object, or in other words, anything that they aren't supposed to eat.

Dogs have a tendency to routinely get into things they shouldn't; the trash, laundry, toys, etc. This is known as dietary indiscretion, meaning that dogs will often eat something simply based off whether or not it smells good to them. Puppies will generally do this more than adult dogs, but it can happen at any age.

This can cause your dog to vomit blood if the ingested object irritates their digestive system, injures their intestines, or is poisonous or toxic to them. Garlic, for example, is poisonous to dogs and can lead to them vomiting blood. This is their body's attempt to rid itself of the poisonous material as well as the digested blood. If you believe your dog has ingested something they shouldn't have, you should take them to the vet to make sure that the issue is handled appropriately.

Broken Blood Vessel

While it may not seem like it, the act of your dog vomiting is violent enough to potentially rupture a blood vessel, or hematoma, leading to blood in your dog's vomit. Bilious vomiting syndrome is the term for consistent vomiting in dogs. This can occur if they are already sick with something, like the flu. If this is the case, the signs of blood will likely be fairly insignificant. The blood will be bright red and in light streaks throughout their throw up. So long as the amount of blood is minimal and your dog does not continue to vomit blood, they should be fine. However, seeing a vet will make sure that the problem is indeed minimal.

Blood Clotting Disorder

A blood clotting disorder, or coagulopathy, could also be the root of your dog's issue. A blood clotting disorder usually points to an underlying issue, like liver failure, exposure to harmful pesticides, or even cancer. All three of these issues are very serious and can lead to more harmful health problems for your pet as time goes on. In this instance, the blood will most likely be a significant amount and recurring. There are usually other signs of bleeding from other body parts as well, which will look like purple tinted regions on your dog's skin.

Chewing On Bones

While bones are a popular treat for our beloved pet dogs, they aren't necessarily the best treat to give to your pet. Animal by-products like bones and rawhide can be rough on your dog's digestive tract, and because of the rigid, brittle nature, can be unsafe. Even though dogs have been chewing on bones since before they were domesticated, looking for a better-suited treat might be better for your pet.

Bones, especially after they're cooked, have the potential to shatter while your dog is chewing on them. While this usually isn't a serious issue, as your dog's digestive system can dissolve the bone fragments, there is always the chance that the shards will cut their mouth, esophagus, stomach, or digestive tract. This can lead to the development of peritonitis, which occurs when bacteria leak into your pet's vital organs through an opening. Peritonitis is a fairly serious condition and should be treated by a vet as quickly as possible. The fragments of bone can also get stuck at various points throughout their digestive system, leading to blockage.

If you notice your dog bleeding or vomiting blood after eating a bone, they should be taken to a vet to assess the seriousness of the issue. In some cases, the issue will resolve itself, while at other times they may need surgery to remove the fragments and repair any internal injuries.

Antifreeze Poisoning

Blood in your dog's vomit could also be the result of antifreeze ingestion. Antifreeze contains the lethal toxin ethylene glycol, which can poison your dog in a very small amount. It is one of the common kinds of poisonings in small household animals due to its easy availability. Homeowners often use it in their toilets during the winter to winterize their plumbing, and it can be found in the radiator of your car. If antifreeze leaks from the bottom of your car, your dog may lick it off of the ground, not realizing the danger of the substance.

Antifreeze poisoning is extremely dangerous and can be life-threatening even if treatment is sought immediately. If you notice your dog is vomiting blood (one of the first signs of antifreeze poisoning) and you have antifreeze around the house, it is critical that you get them to a vet as quickly as possible.

Poison Ingestion

There are other household poisons that your dog could ingest, such as rat poison, that can cause them to throw up blood. Rat poison is a common cause for unexplained bleeding in dogs, along with other symptoms like black, tar-like stool. If you have reason to believe that your dog has ingested rat poison or any other kind of household poison, medical attention should be sought quickly to prevent permanent damage to their digestive system.


Bloody throw up in dogs is one of the advanced symptoms of parvovirus. Parvovirus is an extremely lethal virus in puppies and dogs that moves through their system rapidly. While there is no cure for parvovirus, emergency treatment can help your dog's chances of beating the sickness and recovering. Because bloody vomit is an advanced symptom of parvovirus, the odds of your dog surviving are much more narrow than normal. It is possible for a dog to recover, though, and your pet should be taken to the vet as soon as you suspect that they have parvovirus.

Stomach Ulcer

Stomach ulcers can also cause your dog to develop hematemesis if they are severe enough. Stomach ulcers most often develop as a result of taking NSAIDs like ibuprofen and aspirin for an extended period of time. While these medications are generally safe for humans, it is not recommended that you give them to your dog for a long period of time due to the negative side effects. Corticosteroids, bacteria, and other causes can also lead to the development of stomach ulcers. Because the bleeding originates in the stomach the vomited blood will most likely be partially digested. To tell if this is the case, look for blood that is dark brown or black and has the consistency of coffee grounds.

Bacterial Infection

Your dog could have blood in their throw up from a bacterial infection. Salmonella, E. coli, Campylobacter, and clostridia are a few of the bacteria that can lead to bloody vomit in dogs. Bacterial infections will almost always come with other symptoms, like lethargy, upset stomach, diarrhea, appetite loss, and discomfort. If a bacterial infection is the source of your dog's bloody vomit, then you will need a vet to diagnose the issue so that they can prescribe the proper medication for treating the issue.

Food Allergy

If your dog begins to vomit after being switched to a new food, there is a good chance that they have a food allergy to the new brand of dog food. Dogs are very sensitive to changes in their diet, so it isn't uncommon for them to have an adverse reaction to changes like this. Dog food contains several types of ingredients that dogs can be allergic to, like sweeteners, preservatives, flavorings, wheat, dairy, eggs, corn, and fish. If the allergy is severe enough, there may be blood in your dog's vomit. This is usually accompanied by bloody stool and stomach pain.

If you believe your dog has a food allergy, the best way to resolve it is to check the ingredients of their food, buy a brand with different ingredients, and keep switching their food around until you find one that doesn't upset their stomach. If this doesn't reduce their vomiting or the amount of blood in their vomit increases, then consult with a vet to make sure that a food allergy really is the root of the issue.


Because dogs spend so much time outdoors, digging, exploring, and getting into things they shouldn't, they are prime candidates for contracting parasites. Some parasites may damage your dog's digestive system, eating holes in their intestinal wall and stomach. While one parasite is unlikely to cause bloody vomit, having multiple parasites most definitely could. This is usually paired with bloody stool.


While less common, your dog could be vomiting blood due to the development of stomach cancer. Tumors that develop in their stomach and esophagus can bleed on their own or cause bleeding, which your pet will expel by throwing up. This is one of the many reasons why it's vitally important that you take your dog to the vet if you notice blood in their vomit.

Stomach Inflammation

Bloody vomit can be caused by chronic gastroenteritis, also known as long-term stomach inflammation. This extended period of digestive irritation paired with frequent vomiting can damage their system enough to lead to blood in their vomit. If your pet has been throwing up consistently for longer than a week, they should be taken to a vet to determine the cause of the issue.

Hemorrhagic Gastroenteritis (HGE)

If your dog's bloody vomit and diarrhea symptoms seem to appear out of nowhere and quickly become severe, it is possible that they have hemorrhagic gastroenteritis. Hemorrhagic gastroenteritis is a severe disease in dogs that has the potential to be fatal if untreated. It is especially dangerous to small dogs as the loss of fluids can be difficult to counter. While vets aren't entirely sure what causes HGE, stress, anxiety, allergic reactions, and dietary changes are all believed to be possible factors at play. If your dog begins to vomit blood and has symptoms of diarrhea in a short period of time, take them to the vet quickly in case it is HGE.

Other Sources of Bleeding

There is also the possibility that the blood in your dog's vomit is originating from somewhere else. Cuts in their mouth or esophagus can occur after chewing on something sharp, which is fairly non-serious. Bleeding gums are a symptom of gum and dental diseases as well. If you notice blood in your pet's vomit that appears bright red and occurs in small amounts, check their mouth for cuts or scrapes that could be causing the bleeding. If you don't see any, or the bleeding doesn't stop on its own, then they should be taken to the vet.

What To Do If Your Dog Is Throwing Up Blood

As has been mentioned countless times throughout this article, the number one thing you can do for your dog if you notice blood in their vomit is to take them to a vet. Because the causes can range from minor issues to life-threatening emergencies, and the symptoms are generally shared, it's in your dog's best interest to take them to a professional who can evaluate them professionally and make sure that the issued is treated appropriately. All of the aforementioned issues are survivable if treatment is sought quickly after the bloody vomit is noticed.

The only time that you shouldn't rush your dog to the vet is if you can see cuts on their mouth or have a very good reason to believe that is a result of a food allergy. Even still, there is no harm in taking them to the vet and making sure that the issue is as harmless as it seems.

How To Determine The Cause of Blood In Your Dog's Vomit

While it's not necessarily possible to determine the exact cause of your dog's bloody vomit on your own, there are signs you can look for that will help narrow down the source cause.

For one thing, think about anything in your dog's environment or routine that may have changed recently to cause the issue. A change in food, treats, medication, or exposure to materials like poisons. The next thing to pay attention to is your dog's behavior. Are they moving or acting strangely, lethargic, irritable, or do they seem their normal selves aside from the vomit? And lastly, you want to watch for concurrent symptoms. Is the vomit their only symptom, do they seem to be in pain, are they having diarrhea or bloody stool, are their gums pale, or their skin purple-tinged? All of this information will help you narrow the problem down to a few causes, which will help the vet diagnose your pet faster.

Blood In Mucus

Another thing to look for is the amount of mucus in your dog's bloody vomit. Blood that is high in mucus usually points to upper intestinal and stomach bleeding, ulcers, or inflammation. Blood that is dark, tar-like, and foul-smelling usually indicates an issue in your dog's lower intestine. While being able to differentiate between the two will be a little difficult, making your best guess will give you more information to provide your vet with.

Diagnosis and Tests For Dogs Vomiting Blood

After you've thoroughly assessed your dog's condition on your own and created a list of their symptoms and potential causes, you should seek vet assistance as quickly as possible. They will likely need a complete medical history for your pet along with any information you can provide about the problem. From there, they'll conduct blood tests, urine and fecal analysis, ultrasounds, and x-rays. This will give the vet a thorough idea of your dog's current condition and clue them into the underlying cause.

Treatment For Blood In Dog's Throw Up

Since so many of the causes of blood in a dog's vomit are life-threatening, your vet will most likely seek emergency treatment to fight the problem. If the loss of blood is significant enough, your pet may need a blood and plasma transfusion to build their resources back up. Because vomiting also causes a loss of fluids, your pet may need to receive intravenous fluids and electrolytes to bring their system back into balance.

Bacterial causes will most likely be treated with antibiotics to stop the vomiting from continuing. If your pet has parvovirus or another viral infection, your vet will focus on managing the systems and keeping your dog's condition as stable as possible. Poisoning or medication overdoses might be treated with activated charcoal or a stomach pump to rid their system of the harmful material. Internal injuries or tumors may require surgery.


If you notice that your dog is vomiting blood, the best thing you can do is get them to a vet as quickly as possible. Even though some of the causes are relatively harmless, the risk of a serious issue is too great to ignore. So long as quick treatment is provided, your dog should be able to survive the ordeal with minimal long-term damage.





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