“Why does my dog vomit?” is a question heard by veterinarians all the time. Vomiting is relatively common occurrence in dogs, and acts as natures first defense in expelling unwanted food or foreign objects that may have been ingested. However, vomiting is not always a simple problem, and dog owners should be aware of the common causes of vomiting.

Vomiting is a result of irritation of the stomach, and can be split up into two main categories, acute (a sudden episode of vomiting, often just one time) and chronic (vomiting one or more times a week on a regular basis).

Acute vomiting can be caused by something as simple as eating grass, or something as serious as a twist in the intestines.

The occasional episode of throwing up is not necessarily indicative of a major medical problem in dogs. Diet changes, a dog getting into the trash, and getting car sick are among the most common causes of vomiting in dogs. In most of these cases when a dog has vomited only once or twice, and continues to act and feel normally, vomiting is not a major concern. In cases of dietary indiscretion, withholding food (but encouraging water drinking) for 24 hours can help the digestive system to recover from the upset. After this time, a small amount of a bland diet (i.e. white rice and chicken) can be offered, and if the pet has a good appetite and is able to eat without further episodes of vomiting, the dog can be slowly switched back to his regular diet.

Regurgitation is a problem commonly seen in small dogs, puppies, and dogs on dry food diets that tend to “inhale” their food as quickly as possible. When eaten, dry food absorbs moisture from the dogs stomach and expands in size, and can cause regurgitation of the undigested food. Soaking dry food before feeding it, as well as feeding smaller meals throughout the day can help to alleviate this problem.

In puppies, vomiting is often a sign of the presence of common internal parasites. Roundworms are passed to puppies from their mothers, and the parasites grow quickly, with puppies showing symptoms of infestation at only a few weeks of age. A pot-bellied appearance, poor growth and a rough, dull hair coat are signs of a worm infestation.   Roundworms can grow to seven inches long, and can appear in the stool looking like spaghetti. In severe cases puppies may begin to vomit large quantities of these worms, and if allowed to continue unchecked the worms can cause pneumonia, intestinal problems and death. Other parasites, such as Giardia and coccidia may cause vomiting as a side effect of their presence in a puppy. Fecal testing and deworming is recommended for all puppies to ensure they are free of parasites.

Another, more deadly cause of vomiting in puppies can be from Canine Parvovirus. Puppies that are unvaccinated, or have not yet completed their vaccination series are most susceptible to this disease that attacks and kills the cells in the intestinal lining. Dogs with parvo develop a high fever, lethargy, loss of appetite and vomiting. Profuse, liquid diarrhea occurs as the damage to the intestinal tract progresses, and may be foul smelling, or have blood in the stool. Fluid loss from the diarrhea and vomiting quickly leads to severe dehydration, shock and death, and is often fatal, even in dogs diagnosed and aggressively treated for the disease.  Vaccination is the best prevention for development of Parvo.

While not all cases of sudden vomiting are a sign of serious problem, sudden, repeated episodes of vomiting should always be treated as a medical emergency.

While many dogs will eat things they shouldn’t, and most emerge unscathed, a dog that has ingested a large amount of anything should be monitored for abdominal pain and vomiting, as an intestinal obstruction may occur.

Regardless of the item swallowed, once it has entered the dogs intestinal tract, foreign objects may quickly prove too large to pass through the rest of the increasingly smaller digestive system, and can at some point become stuck. This intestinal blockage quickly becomes an emergency situation. A partial blockage in the intestines may produce vomiting, diarrhea and cramping of the abdominal muscles. A complete blockage will cause severe abdominal pain, abdominal bloating, and repeated, frantic, projectile vomiting. Depending on the location of the blockage, fecal-like matter may be vomited, while in other situations the vomit may be only bile. 

If a dog has an obstruction and it is not treated, the intestine surrounding the blockage can begin to die off, causing the gut to leak or rupture, leading to a severe systemic infection. Emergency surgery is indicated in these dogs to remove the foreign object and repair the intestines as quickly as possible.

Gastric dialation-volvulus, commonly known as bloat, is a life-threatening condition affecting large breed dogs. Dogs fed a large meal once daily, especially those that eat their meals rapidly, are at greatest risk. As their stomach fills, gastric distention occurs. Increased activity shortly after a meal can cause the stomach to twist, closing off the esophagus, and leaving them unable to expel gas or excess food in the stomach by vomiting or belching. Signs of bloat include a distended abdomen, pain, salivation, and repeated, unproductive attempts to vomit. Bloat is serious medical emergency, and if you suspect your dog is suffering from this condition, time is of the essence to save his or her life.

While acute vomiting can be caused by many serious emergencies, chronic vomiting in dogs should also be treated with seriousness and caution.

Dogs that vomit more than once or twice a week without an obvious cause have chronic vomiting. Chronic vomiting can lead to poor digestion and absorption of nutrients, and as such dogs will often have a low energy level and poor quality hair coat.

Food allergies and intolerances are the most common cause of chronic vomiting. Similar to lactose intolerance in people, dogs may have or develop allergies or sensitivities to variety of ingredients in dog food, leading to chronic inflammation in the stomach and intestinal tract. Food trials may be recommended by your veterinarian to try and identify the ingredient that your dog is sensitive to, and eliminate it from his or her diet.

Pancreatitis can present in dogs in both an acute form, as well as a chronic problem. The pancreatic gland is responsible for secreting hormones such as insulin and glucagons into the bloodstream to regulate blood sugar levels, as well as making the digestive enzymes that break down food for digestion. Pancreatitis, or inflammation of the pancreas, can cause these digestive enzymes to decrease, and in severe cases the enzymes may begin to digest the actual organs of the dog instead of food. Diarrhea, abdominal pain, vomiting and a poor appetite are the symptoms of pancreatitis, but because these symptoms are shared with so many other gastrointestinal problems, it can be hard to diagnose.

“Why does my dog vomit?” may be a common question that veterinarians hear, but the answer is hardly one size fits all. A veterinarian should evaluate any dog that is experiencing episodes of vomiting, to help diagnose and treat any possible underlying conditions that may be causing the vomiting, and adversely affecting the dogs health.