10 reasons your dog might be throwing up

10 Reasons Your Dog Might Be Throwing Up

Vomiting in dogs is often taken as a sign of a problem in our furry friend’s digestive tract. For some pet parents a dog that is throwing up is usually not a cause of concern especially if it ceases soon after. However, if the vomiting has persisted for quite some time and is accompanied by other clinical manifestations such as signs of dehydration and electrolyte abnormalities, then there really is cause for great concern. But the thing is that there can be a hundred and one different reasons why your dog might be throwing up. Here are 10 of them.

1. Eating Slugs and Snails

One of the most likely reasons your pet is throwing up is that it ate a slug, a shell-less mollusk that is quite common right in our own backyards along with snails. Some dogs have a knack for eating slugs and snails turning these into their canine version of escargot. While slugs and snails are not really dangerous themselves the problem is when they harbor parasitic worm known as Angiostrongylus vasorum. The parasite is more commonly known as the lungworm and can wreak havoc in your dog’s blood vessels supplying the pulmonary tree. This can lead to a variety of other manifestations, not only severe vomiting and diarrhea.

dog feeling sick

Your dog might throw up since the body is trying to get rid of the slugs and / or snails that it has ingested. This is especially true if these organisms have ingested slug baits as these chemicals can irritate your dog’s tummy. In turn, the irritation of the gastric or intestinal lining causes spasms in the muscles of the digestive tract leading the increased propulsive action.

The point is that whenever your dog happens to eat slugs or snails from your backyard there is a tendency that it will vomit in an attempt to get rid of the irritating substances inside its digestive tract. If you see other manifestations such as difficulty breathing, weakness, pallor, or increased bleeding tendencies, there’s a great chance that your pet already has lungworm infection. Do take note that this is a very serious infection that can terminate in the loss of life of your pet.

2. Food allergies, Food intolerance, or Change in Food

Any change in your dog’s diet can lead to stomach upsets which can easily translate into your pet throwing up. Of course this has to be taken in the light of other clinical manifestations or the context upon which the vomiting has occurred.

Different dog foods come with different formulations mostly based on the ingredients that are used. There are some ingredients that are more difficult to digest than others which can lead to stomach upsets. An upset stomach can manifest itself as diarrhoea and, of course, vomiting or even nausea as the digestive tract of the dog attempts to dislodge the food material.

There are also instances when a dog is being given an entirely different food from what it is accustomed to. If the change in diet is done suddenly there is a possibility that the dog’s digestive system may not have the time to fully adjust to the new formulation. Now add the presence of allergenic ingredients in the new formulation and it is rather easy to see why your dog will be throwing up.

It is for this reason that pet parents are advised to give their dogs new kinds of food gradually. Dividing the dog food into quarters, the first week may be composed of 75% current dog food and 25% of the new dog food. If there are no untoward reactions pet parents can proceed with a 50-50 composition on the second week. If there are still no reactions 75% of the dog’s food should then be composed of the new formulation for the third week. If the dog successfully hurdles the 2rd week without vomiting or any other sign it can be fed with the new dog food formula beginning on the 4th week.

There are also human foods that can cause your dog to throw up. These can include chocolates, mushrooms, grapes, fruit pits, avocados, and raisins among others. While some dogs can tolerate these foods in very small amounts there really is no telling if your dog can access these food items on their own.

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3. Ingestion of Foreign bodies

Dogs are naturally curious. This is especially true among puppies. Just like toddlers and preschoolers, puppies and juvenile hounds love to explore their surroundings. When this is combined with their natural tendency to chew almost everything that they can put in their mouths you may have objects finding their way into their stomachs.

If the objects are small enough these can easily pass through the rectum and the anus, mixed in the stool. However, if it is big enough it can cause blockage in the intestinal tract. This can cause a variety of problems. Since the blockage will create a pressure differential on the opposing sides of the obstruction, one side will have less pressure while the other one will have increased pressure.

Sadly, the area where there is increased pressure will be in the section between the dog’s stomach and the blockage. Increasing the pressure within the stomach and the small intestines can cause gastric contents to be propelled backwards resulting in their explosive removal.

Dogs are known to take in almost anything. From plastic toys to socks to hair pins, grass, small balls, strings, dental floss, and even rubber bands. Dogs that love to go through the garbage searching for their own version of truffles eventually end up picking something that they can push right down into their stomachs.

When these objects irritate the digestive lining they can cause very powerful contractions sending these objects outwards in all directions. If the movement is towards the mouth you’ve got vomiting. If it’s towards the rectum you’ve got canine diarrhea.

4. Ingestion of Toxic Substances

There are a lot of substances that are especially toxic to dogs. Human toothpastes, for instance, can cause gastric irritation and upset leading to vomiting and a host of other manifestations. Antifreeze toxicity is quite common since it has a rather sweet taste. Unfortunately it never leaves a sweet feeling to your dog’s tummy. Cleaning products can be especially dangerous to pets. Sadly, we often take for granted our way of keeping these products secure.

reasons why dogs throw up

Even human medications can bring stomach upset that can lead to a major throw up episode for your dog. Some pet parents are not cautious enough when storing their prescription medications that many are left on the counter which can be easily accessed by your curious dog. Even multi-vitamin preparations for humans can create quite a stir in our dog’s tummies making them want to throw up.

The point is that if you look at our homes you can instantly see a lot of potentially toxic products just lying in wait. Bars of soap, insect repellents and insecticides, and even the ordinary household bleach can be found in almost any home. These products can seriously injure the lining of the stomach, leading to more problems and not just vomiting in dogs. As such it is imperative that you keep all of these potentially toxic substances from your dog.

5. Liver or Gallbladder Disease

One of the most common manifestations of a problem in the liver or even in the gallbladder is vomiting. While the exact mechanism is poorly understood, liver disease can lead to the accumulation of toxic substances in the blood which can trigger the vomiting center in the dog’s brain.

The liver is a very important organ responsible for hundreds of different functions, although its principal function is in the detoxification of substances in the body. Anything that finds its way into the bloodstream whether inhaled and diffused through the lungs or ingested and absorbed in the small intestines will go through the liver where it will be rendered harmless. Once detoxified, these ‘cleansed’ substances are then recirculated through the blood and excreted in a variety of ways.

A liver that is diseased means the individual liver cells – the hepatocytes – are no longer able to carry out their detoxification function as efficiently as they once did. This leads to the accumulation of toxic substances in the blood which can trigger the vomiting center in an attempt to get rid of such substances. Unfortunately, since the substances are already in the blood what your dog will be throwing up are a mixture of gastric acids and food particles.

The gallbladder serves as the storage for bile, an important body fluid in the emulsification of fats so that digestive enzymes can easily break them down. That is why if there is a problem in the gallbladder such as inflammation or the presence of a gallstone, there will be insufficient amounts of bile in the duodenum. If there is fat in the dog’s diet this will not be digested properly leading to the passage of fatty stools.

Regrettably, the presence of undigested fat in the small intestines also triggers the vomiting reflex in an attempt to clear these fatty substances. As such you can expect your pet to throw up as well.

6. Pancreatitis

The pancreas is important in two fundamental respects. First, it has an endocrine function whereby both insulin and glucagon are produced. Diabetes, a metabolic problem characterized by an abnormally elevated blood sugar level, can be traced to a dysfunction in the insulin mechanism. In type 1 diabetes, the pancreas is not producing insulin. In type 2, there is insulin but may be insufficient or may have problems with its functionality.

While not very common, vomiting can occur in diabetic dogs because of a variety of reasons. The fluctuations in blood glucose levels can confuse the body’s normal metabolic processes, preventing it from adapting to the changes in a more efficient manner. This can produce nausea and vomiting. This can be worsened by gastroparesis or the ‘paralysis’ or weakness of the musculature of the digestive tract secondary to nerve damage. Because digested food cannot move efficiently through the intestinal tract, pressure builds up in the upper digestive tract resulting in vomiting.

Second, the pancreas also has a digestive function. It is responsible for the production of digestive enzymes such as lipases, proteases, nucleases, and amylases to help digest fats, proteins, nucleic acids, and carbohydrates, respectively. In the presence of chyme in the duodenum, these enzymes are released to continue the work started by the mouth and the stomach.

If there is a problem in the pancreas it will not be able to produce these digestive enzymes. What happens is that your dog will not be able to digest its food increasing the pressure in the small intestines and triggering vomiting. Of course, this is in addition to a host of other signs and symptoms.

7. Side Effects of Drugs

Almost every other medication whether it is FDA-approved for veterinary use or not has the tendency to cause vomiting in dogs. Generally, any medication that can irritate the stomach can produce nausea and vomiting. Nonsteroidal anti-inflammatory drugs or NSAID painkillers are notorious for causing gastric upsets which can lead to vomiting. These can include Ibuprofen and Ketoprofen, just to name a few.

canine throwing up

Narcotic pain relievers like Tramadol can also produce vomiting in dogs. Antibiotics and steroids also have the tendency to make your dog throw up. If your pet is receiving cancer chemotherapy or even radiation therapy, it will also throw up.

It is, therefore very important that these medications be given to your dog with its meals to help minimize gastric irritation and trigger vomiting. What’s clear is to follow the recommended dose administration by a vet.

8. Bacterial and Viral infections

There are many causes of gastroenteritis in dogs. Among the most common bacteria that can cause canine gastroenteritis includes Clostridium perfringes, Campylobacter species, Clostridum difficile, Escherichia coli, and Salmonella species. Bacterial gastroenteritis results from the colonization of the digestive tract of these bacterial organisms. One of their effects is inflammation of the digestive tract which can speed up the peristaltic movement of the intestines. This can radiate throughout the entire length of the digestive tract. Going downwards it can produce one of the classic manifestations of gastroenteritis, diarrhea. The same propulsive action directed upwards can induce vomiting because of increased pressure in the stomach.

Viral infections of the dog’s intestines can be brought about by rotaviruses, coronaviruses, parvoviruses, astroviruses, distemper virus, canine reovirus, and even herpesvirus, although it is rotaviruses that are the most common culprit. They may have a different mechanism of disease causation, but the end result is almost always the same. These can produce not only vomiting, but also diarrhea secondary to inflammation of the intestinal tract.

9. Intestinal Parasitism

Tapeworms, hookworms, and roundworms as well as other parasites known to infest the dog’s intestines can also make your dog throw up. These should be differentiated from bacterial and viral infections of the dog’s gastrointestinal tract since they do operate on a variety of disease-causing mechanisms.

Roundworms, if left to grow and proliferate, can block the small intestines causing increase intragastric pressure and causing vomiting. The presence of roundworms in the intestines can also irritate the intestinal lining, creating increased peristaltic movement which can aggravate nausea and vomiting. Hookworms are notorious for migrating to the dog’s lungs where they can grow into a massive ball. Some of them return to the dog’s intestines by way of the lymphatics to continue on their journey. These can also produce vomiting because of intestinal irritation. Tapeworms are large intestinal parasites that can easily form a massive ball, potentially blocking the small intestines. They’re mostly known for sapping the dog’s nutrient supply so the dog goes severely malnourished.

The mere presence of these parasites in the intestines can already trigger a vomiting response to rid the tract of these unwanted visitors. In other words, vomiting can be both an effect of the activities of these parasites or a reaction by the dog’s body to get rid of these organisms.

10. Kidney disease

If the liver is best known for detoxifying substances before they are eliminated from the dog’s body, the kidney is considered the last line of defense making sure that these substances do exit the dog’s body. When blood goes to the kidneys, it passes through a filtering mechanism so that all the unwanted substances are filtered out, returning a relatively ‘clean’ blood to the rest of the circulation.

throwing up dog

If there’s an issue with the kidney’s ability to filter blood, then these substances will not be removed from the dog’s body. Most of these substances contain nitrogenous wastes such as urea. The presence of urea in the blood, known as uremia, can trigger the vomiting center in the dog’s brain to attempt to get rid of the ‘toxins’.

If your dog is showing signs of throwing up it could easily mean any of the 10 things that we have shared in this article. If the vomiting is persistent and is accompanied by other manifestations you should contact your vet immediately.

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  1. Stephanie Lantry, DVM, Why Is My Dog Vomiting?, PetMD
  2. Dog Vomiting 101: Why it Happens, Found Animals
  3. Vomiting and Diarrhea, The MU Veterinary Health Center

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Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.