Unlike the innocuous vomiting most dogs do a few times a year, more frequent vomiting is often a symptom of something more serious.

People often assume that vomiting means there’s a problem in their dog’s stomach. While this is true in some cases, several things, unrelated to the stomach, can cause vomiting. Figuring out which one is the culprit requires help from a veterinarian.

Here are the most common causes of vomiting in dogs:

Eating inappropriate things

Dogs are masters at eating things they shouldn’t. Raiding the garbage pail or gulping down some sort of yuck in the backyard can cause irritation in the stomach and/or intestinal lining. Much like a case of food poisoning in people, this sort of vomiting typically resolves on its own after 12 to 24 hours.

Gastrointestinal foreign bodies

When a young dog comes in with vomiting, one of the first things to rule out is a foreign body. Bones, rocks, children’s toys, socks, underwear, corn cobs, coins, keys—I’ve removed all these things and more from a dog’s gut. Some foreign bodies pass through on their own, but others become lodged and cause persistent vomiting (corn cobs are notorious at this).

String foreign bodies (shoestring, yarn, fishing line, etc,) are an entity unto themselves. One end of the string anchors at a particular point in the gut while the rest of it trails through the intestines. As peristaltic waves (think of a snake here) pulse through the gut, loops of bowel bunch up the way fabric does on a drawstring.

If determined that the foreign body won’t pass on its own, removal is necessary. This is best accomplished via surgery or a nonsurgical procedure called endoscopy. What are the most unusual foreign bodies I’ve ever retrieved? The two that stand out are a troll doll in an extremely large dog (I thought I’d come across something alive in the stomach) and a woman’s diamond wedding ring.

Inflammatory bowel disease (IBD)

Some dogs develop inflammation within the lining of their bowel, that we refer to as IBD. If the stomach or small intestine are involved, vomiting is a common symptom. The diagnosis is confirmed via biopsies. Allergies may play a role, but truth be told, sometimes an underlying cause can’t be tracked down. Treatment typically involves diet modification and the use of anti-inflammatory medications.

Toxicities

A variety of toxins can cause vomiting and are especially problematic for dogs who have little dietary discretion. Some toxic substances include poisonous plants, rotten meat or carcasses, a variety of human medications, blue-green algae, antifreeze, and snail bait. Some toxins are life threatening, such as Amanita mushrooms, antifreeze, and snail bait. The sooner treatment is initiated, the better.

Pancreatitis

The pancreas is a boomerang-shaped, delicate organ that nests against the stomach and upper small intestine. So, it makes sense that vomiting occurs when the pancreas becomes inflamed. In addition to vomiting, pancreatitis often causes lethargy and abdominal pain. Hospitalization is usually required for administration of medications and intravenous fluids. The cause of pancreatitis isn’t always clear, but it often arrives on the heels of eating something fat-laden, such as Thanksgiving scraps (buttery mashed potatoes or the turkey’s skin).

Liver disease

Vomiting is a common symptom associated with most every flavor of canine liver disease. Resolving the liver disease typically resolves the vomiting.

Kidney failure

Poorly functioning kidneys cause a backup of toxins in the bloodstream, and one of the most common symptoms is vomiting. Therapy often includes supplemental fluids, administered at home or in the hospital, along with a change in diet. The underlying cause of the kidney failure dictates additional treatments.

Gastrointestinal tumors

Tumors that arise within the stomach and/or intestines can be benign or malignant. Regardless of the tumor type, vomiting is a common symptom. A tumor that causes a blockage (obstruction) in the bowel causes incessant vomiting. Treatment varies depending on the location and type of cancer present.

Pyometra

Vomiting is a common symptom of pyometra (accumulation of pus within the uterus). This disease occurs in unspayed female dogs, most commonly a few weeks following estrus (being in heat). Treatment usually requires removal of the uterus, aka spaying.

Addison’s Disease

The official name for this disease is “hypoadrenocorticism” which reflects a state of having too little cortisone. As a side note—John F. Kennedy suffered from Addison’s disease. The disease occurs when the adrenal glands no longer produce the hormones, cortisone and the aldosterone. Vomiting is one of several symptoms of this disease. Treatment requires hormone replacement therapy. Depending on the severity of symptoms, a period of hospitalization may be required.

Eating grass

Do dogs vomit because they eat grass, or do they eat grass because they feel the need to vomit? This is the classic “chicken versus egg” conundrum. Some dogs simply love munching on grass, especially in the spring, and do so without vomiting. On the other hand, the feeling of nausea or intestinal discomfort causes many dogs to want to eat grass, leaves, twigs, dirt, and whatever else Mother Nature is serving. While it’s tempting to blame the foliage for the vomiting, it is important to dig deeper to figure out why the dog grazed in the first place. And a note of warning—do not let your dog eat from herbicide treated lawns (lawns that look pristine).

Diagnosing the cause of vomiting

Your veterinarian will want a through history from you. Be prepared to provide details about the frequency of vomiting, time of day, regular diet, the appearance of the vomit and bowel movements, and anything unusual your dog may have been ingested.

Depending on physical exam findings, your vet may want to x-ray or ultrasound your dog’s belly. Or, she may start with blood and urine testing to rule out a problem in the liver, kidneys, and pancreas. Your vet may want to collect biopsies via surgery or endoscopy.

When diagnostic testing isn’t possible, your veterinarian might prescribe empirical therapy (treatment without a certain diagnosis).

Is your dog a vomiter? If so, do you know why?

Best wishes to you and your four-legged family members for abundant good health.

Dr. Nancy