Dogs vomit for all kinds of reasons, some can be serious, some mild and resolve on their own. It can be difficult to identify why a dog is vomiting because there are so many different possible causes.
The most common causes of vomiting are dietary indiscretion (getting into something they shouldn’t have: garbage, contaminated water, another dog’s stool, etc.) and getting doggy “food poisoning”. Any change in a dog’s diet can also cause vomiting. There are many other possible causes as well:
Dietary Indiscretions or Changes
Often a change in your brand of dog food can cause vomiting. When changing your dog’s diet, experts recommend slowing it down. Gradually mix in new food while gradually feeding less of the old food. This should occur over the span of a week.
Food allergies typically present as ear and skin problems, but in some cases, gastrointestinal upset can result. Acute food allergies can present as vomiting and diarrhea, and your dog may have a skin flare-up as well.
Foreign Object Ingestion
Some dogs – especially young puppies – have a tendency to chew on things that they shouldn’t. “A lot of dogs don’t discriminate. Toys, rocks, socks, underwear. You name it, and dogs swallow it,” says Dr. Justin Shmalberg of the University of Florida. “These things can get entrapped in the gastrointestinal tract (GIT), causing backups – and the other way around.”
Once an obstruction occurs, most dogs won’t be able to hold down any food or water.
Gastroenteritis is one of the most common causes of vomiting in dogs. It is a broad term that indicates inflammation of the stomach and intestines, causing vomiting and diarrhea. Gastroenteritis can be triggered by diet change, toxin ingestion, infection, and other disease processes that impact other organs.
Vomiting can also be caused by bacterial diseases. Bacteria such as Campylobacter and Salmonella can cause infections of the gastrointestinal tract. These bacteria can result in severe blood poisoning (septicemia) and inflammation of the intestines. These bacteria can also be transmitted from dogs to humans, so care should be taken to avoid contact with a dog’s fecal matter.
Vomiting can be caused by bloat. Bloat or gastric dilatation can turn into gastric dilatation volvulus (or GDV) when the distended stomach flips on itself. This an acute and life-threatening situation requiring patients to be hospitalized and to undergo immediate surgery.
Without surgical intervention, the blood supply to the stomach is cut off and parts of the stomach wall begin to die. This will result in septic shock which can be fatal. Bloat can occur in many dogs, and large-breed and deep-chested dogs are at a higher risk of developing it. Eating or drinking quickly can also be a factor in developing bloat.
Kidney or Liver Disease
Kidney disease and liver disease are broad terms for the illnesses that can impact these organs. Toxin ingestion, trauma, infection, inflammation, and even cancer can affect the liver and the kidneys. When these organs are not functioning properly, harmful metabolites and waste products can build up in the blood stream, resulting in problems like vomiting and diarrhea.
A severe and highly contagious disease (especially for dogs). Symptoms include vomiting, diarrhea, fever, and lethargy. It is most common in unvaccinated young puppies and can cause life-threatening dehydration.
Diabetes mellitus is a chronic condition that involves the presence of too much glucose in the bloodstream. Most cases of diabetes are found in middle-aged and older dogs.
Female dogs are twice as likely to develop diabetes compared to males. Smaller breeds such as Miniature Poodles, Dachshunds, Schnauzers, Cairn Terriers, and Beagles have an increased risk as well. Some of the clinical signs of diabetes include increased urination, increased thirst, increased appetite, weight loss, cataracts, vomiting, and diarrhea.
Bilious Vomiting Syndrome (BVS)
Bilious vomiting syndrome is a poorly understood disease because the true cause is unknown. It is characterized by vomiting bile early in the morning and is thought to be related to the reflux of fluid back into the stomach which irritates the lining of the stomach.
Pancreatitis is characterized by inflammation of the pancreas, which can occur in acute or chronic episodes. It is usually associated with the immediate introduction of a high-fat diet, and dogs who are prone to eating food out of the trash may be more likely to develop pancreatitis. There is also a genetic predisposition for some breeds like the Toy Poodle and the Schnauzer.
There are any number of internal parasites that can cause vomiting. Some of the most common like roundworms and hookworms can be easily transmitted to other pets and to people. Protozoans like Giardia are also considered to be parasitic in nature.
Dogs lack enough sweat glands to cool off when they are hot. When panting isn’t enough to decrease their body temperature, they can collapse due to heat stroke. Symptoms include excessive panting, extremely high body temperatures (104 F and higher), vomiting, diarrhea, redness of the gums, inability to move around, and even loss of consciousness.
Chemicals, cleaners, fertilizers, antifreeze, insecticides, and even some plants and common medications can cause severe poisonings. For example, the small orange seed from a Sago palm, which is common in Southern states like Florida, can cause acute liver failure if ingested.
The most common plants that are a nuisance to dogs are the autumn crocus (Colchicum autumnale), azalea (Azalea nudiflora), cyclamen (Cyclamen spp.), dumbcane (Dieffenbachia), and hemlock (Conium maculatum).
Mushrooms can cause neurotoxic signs like stumbling and staggering, which usually results in vomiting. There are many different species of fungi, and the only ones considered safe for ingestion for dogs are the mushrooms purchased from a grocery store.
Primary tumors of the abdomen can affect dogs. Several different types of tumors can grow in a dog’s stomach or other internal organs like the spleen or liver. The tumors can be benign (non-cancerous) or malignant (cancerous) with the possibility of spreading to other parts of the body.
When left untreated, both can grow and interfere with internal organ function, increasing the risk of gastrointestinal ulcers and gastric or intestinal obstruction which can cause vomiting.
Black stools are the result of upper gastrointestinal bleeding, and so this could be another symptom of a tumor. Cancer most commonly occurs in middle-aged and older dogs but can affect dogs at any age.
Dogs can suffer vertigo-like signs due to things like inner ear infections. When this happens, it is referred to as vestibular disease. Dizziness, stumbling, and vomiting can occur.