Vomiting in dogs: causes and when to see a vet

Overview

During true vomiting, abdominal muscles contract visibly. Nausea or retching often precedes it. Regurgitation is passive return of material into the mouth without abdominal effort. Regurgitated food is often undigested and may form a long tube shaped like the oesophagus.

Mild sudden-onset vomiting may improve within 24 hours. Vomiting lasting more than three to four weeks is considered chronic. Even vomiting once a week can be associated with disease.

In one emergency follow-up, the cause was identified in 60 of 99 dogs. It remained unknown in 39. Median duration before presentation was eight hours. The median number of episodes before the visit was five.

Causes

Digestive tract causes

Dogs may vomit after eating spoiled food or other unsuitable material. A swallowed foreign body can block food passage from the stomach or through the intestine. Obstruction can also occur when one bowel segment slides inside an adjacent segment. Sudden severe vomiting with pain in the front of the abdomen may be associated with pancreatitis. Parvovirus can cause vomiting and bloody diarrhoea.

Chronic intestinal inflammation can cause intermittent recurrent vomiting. An unsuitable dietary ingredient can also maintain symptoms.

The stomach or intestinal lining can become inflamed through infection or irritation. Internal parasites can underlie persistent vomiting. Cancer is another possible cause of a long-lasting symptom.

Vomiting originating elsewhere in the body

Acute vomiting can occur with uterine infection. Kidney failure can cause vomiting. Liver disease may also be responsible. Swallowed poison or an irritant can trigger vomiting.

Hypoadrenocorticism, or Addison's disease, can resemble intestinal disease. An electrolyte disturbance originating outside the digestive tract can also cause vomiting.

Risk factors

A dog chewing objects may swallow a fragment of toy or fabric. Young large-breed dogs develop foreign-body obstruction more often than older dogs. Large, deep-chested dogs are particularly prone to gastric dilatation and volvulus, or GDV. Inadequate vaccination increases suspicion of parvovirus in a vomiting puppy.

Puppies aged six weeks to six months are most vulnerable to parvovirus when maternal protection has waned before vaccine protection develops. A swallowed corn cob can lodge in the digestive tract.

Puppies have an increased risk of swallowing foreign objects. Pyometra risk is greatest for a couple of months after oestrus.

Typical symptoms

Behaviour may change before vomiting. A dog may vomit several times within a short period.

• Increased drooling before vomiting.
• Repeated swallowing.
• Restlessness before vomiting.
• Strong abdominal contractions while vomiting.
• Reduced appetite with nausea.
• Diarrhoea alongside vomiting.

In the emergency follow-up, 61 of 99 dogs also had diarrhoea. Of those, 31 of 61 had bloody faeces. Vomiting was the only symptom in 32 of 99 dogs.

Vomit may contain food, fluid or swallowed material. Coffee-ground-like material may be digested blood. A dog can lose weight with long-lasting or recurrent vomiting.

Abdominal pain can make a dog whine or pace restlessly. A painful dog may lower the chest to the ground while keeping the hindquarters raised. Black, tarry faeces can indicate bleeding in the stomach or small intestine.

Complications and consequences

Persistent vomiting can cause dangerous dehydration. Electrolytes such as chloride and potassium may be lost. Heavy vomiting can alter blood acid–base balance. Inhaling vomit can cause pneumonia.

An obstructed bowel wall can be damaged as blood supply deteriorates. Perforation can allow contents to cause peritonitis. GDV can compress major abdominal blood vessels and cause shock.

With GDV, the stomach can press on the diaphragm and impair breathing. Its wall can develop tissue death when circulation is compromised. A puppy with parvovirus can rapidly dehydrate through substantial diarrhoeal fluid loss.

Diagnosis at the vet

History and general condition

The vet asks when vomiting began and how many episodes occurred. Possible rubbish or poison ingestion can influence test selection. General examination may include feeling the abdomen for pain or swelling. Rectal examination can look for blood or signs of unsuitable material ingestion.

Tiredness and abnormal responsiveness can increase the need for blood tests. Persistent or severe symptoms may also warrant urine and faecal testing. Suspected parvovirus in an unvaccinated puppy can be tested in diarrhoeic faeces.

The vet may assess dehydration through gum moisture and skin elasticity. Severe abdominal pain was associated with a more complicated course in the emergency follow-up.

The vet may ask about usual food and previous digestive symptoms. The mouth may also be examined if swallowing is difficult. In a severely affected dog with suspected obstruction, blood tests may include chloride measurement.

Imaging and, when needed, biopsies

Abdominal X-rays can look for a foreign body causing vomiting. Not all objects are directly visible, but bowel enlargement can suggest obstruction. Ultrasound may be more useful with prolonged vomiting and reduced appetite. Suspected GDV can be confirmed with abdominal X-rays.

Gastroscopy and small-intestinal endoscopy may help investigate chronic vomiting. Mucosal biopsies can be taken during endoscopy. With repeated regurgitation, oesophageal diseases are investigated separately.

In the emergency study, ultrasound led to a diagnosis in three of 99 dogs. Two cases diagnosed by ultrasound involved pyometra. With GDV, an ECG can help identify arrhythmias.

Treatment

Symptom relief and fluids

The vet prescribes treatment according to the cause and general condition. Severe dehydration may require intravenous fluids in hospital. Fluids can correct vomiting-related electrolyte changes. An antiemetic may be given for persistent vomiting after veterinary assessment.

Once vomiting eases, small portions of easily digestible food can be offered. Normal feeding can resume gradually if eating does not trigger vomiting again. In the emergency follow-up, vomiting stopped with symptomatic treatment within four to five days in 34 of 99 dogs.

In the group whose symptoms led to further investigations or surgery, for example, 53 of 65 dogs received hospital care.

Treating the underlying cause

A suitable foreign body still in the stomach can sometimes be removed endoscopically. An object lodged in the intestine and causing obstruction may require surgery. Initial GDV treatment includes supporting circulation with intravenous fluids. The twisted stomach is repositioned surgically.

During obstruction surgery, bowel damaged by loss of blood supply may need removal. Once a twisted stomach is repositioned, it is usually attached to the abdominal wall to prevent recurrence.

Prevention

Puppy parvovirus vaccination helps prevent infection causing severe vomiting and diarrhoea. Protect weaned puppies from exposure until vaccine protection develops. Keep socks and small, easily damaged toys out of reach to prevent foreign-body obstruction. Keep avocado stones and bones inaccessible because they can lodge in the digestive tract. Preventive attachment of the stomach to the abdominal wall can reduce GDV risk in predisposed breeds.

Some kennel clubs require a dog recovering from parvovirus to be symptom-free for at least two weeks before attending their events.

Important for dog owners

Record onset time and the number of vomiting episodes to tell the vet. Contact a vet if vomiting continues for more than six hours, even if your dog remains bright. Contact a vet about blood or coffee-ground-like material in vomit.

Do not give human medication without veterinary advice. A vet decides whether to induce vomiting after a swallowed foreign body. Salt can cause life-threatening poisoning.

Keep drinking water available at home because withholding it can worsen dehydration. Seek earlier advice for a puppy, very small dog or elderly dog. Vomiting also warrants a low threshold for assessment in dogs with diabetes or Addison's disease, for example.

If a sharp object was swallowed, describe it because vomiting it back could injure the oesophagus. Call a vet if mild intermittent vomiting has occurred over more than 24 hours.

If a vomiting dog has abdominal tenderness, immediately ask a vet how urgently care is needed. Mention reduced appetite too.

Frequently asked questions

Can I monitor a single vomiting episode at home?

A single episode can be monitored if the dog is otherwise bright and keeps water down. Contact a vet if vomiting continues for more than six hours. Seek advice earlier if general health deteriorates or blood appears.

How do I recognise regurgitation?

Material returns to the mouth without the abdominal effort typical of vomiting. Food may be undigested and shaped like the oesophagus. If it recurs, tell the vet there is no visible abdominal effort, as it may relate to the oesophagus.

Can frequent vomiting indicate disease?

Even vomiting once weekly can be a disease symptom. Persistent symptoms may warrant blood, faecal and urine samples. If the cause remains unclear, investigations can continue with stomach or small-intestinal endoscopy.

When is vomit colour concerning?

Coffee-ground-like material can be blood altered in the stomach. Contact a vet about blood or coffee-ground-like material in vomit. Seek immediate emergency care if there is a lot of blood or gums are pale.

Why does my dog retch without bringing anything up?

Repeated unproductive retching with rapid abdominal swelling may suggest GDV. Seek immediate emergency care if these occur together: twisting can obstruct blood return to the heart and rapidly cause shock.