Common Causes of Vomiting and Diarrhoea in Dogs and Cats

Vomiting and diarrhoea are two of the most common reasons dogs and cats visit the vet. In some cases, they are caused by something relatively minor, such as eating something they should not have. In other cases, they can be signs of a more serious illness that requires prompt veterinary treatment.

While an isolated episode of vomiting or a short bout of diarrhoea may not always be cause for alarm, it is important to pay attention to your pet's other symptoms and how they are behaving.

Why is my dog or cat vomiting?

Vomiting occurs when the stomach or upper intestinal tract forcefully empties its contents. There are many possible causes, including:

Eating something they shouldn't

Dogs in particular are well known for eating things that do not agree with them. Getting into the rubbish, eating table scraps, raiding the garden or consuming spoiled food can all result in vomiting and diarrhoea.

Cats can also develop a stomach upset after eating inappropriate foods, although they are generally less inclined to eat random objects than dogs.

A sudden change in diet

Changing your pet's food too quickly can upset their digestive system. This can happen when introducing a new food, changing brands or suddenly offering rich or unfamiliar treats.

Dietary changes are best made gradually over several days to give your pet's digestive system time to adjust.

Gastroenteritis

Gastroenteritis means inflammation of the stomach and intestines. It can be caused by something your pet has eaten, an infection or a number of other factors.

Pets with gastroenteritis may vomit, have diarrhoea, lose their appetite or seem quieter than normal.

Parasites

Intestinal parasites such as worms and Giardia can cause vomiting, diarrhoea, weight loss and changes in appetite. Young animals can be particularly vulnerable to the effects of parasites.

Regular parasite prevention and appropriate faecal testing can help identify and manage these problems.

Eating foreign objects

Dogs and cats can sometimes swallow objects such as toys, socks, bones, string or pieces of household items. A foreign object can become lodged in the stomach or intestines and cause a potentially life-threatening blockage.

Repeated vomiting, abdominal pain, loss of appetite, lethargy or an inability to pass faeces can be signs of an obstruction and should be treated as an emergency.

Toxins and poisons

Some foods, plants, medications, chemicals and other substances can be toxic to pets. Chocolate, grapes and raisins, some human medications and certain household products are examples of substances that can cause serious illness.

If you think your pet may have eaten something toxic, do not wait for symptoms to develop. See veterinary assistance immediately.

Pancreatitis

Pancreatitis is inflammation of the pancreas and can cause vomiting, diarrhoea, abdominal pain, lethargy and loss of appetite. Dogs can develop pancreatitis after eating particularly fatty foods, although there are many possible causes.

Cats can also develop pancreatitis, sometimes with less obvious symptoms.

Other illnesses

Vomiting can sometimes be a symptom of a problem outside the digestive system. Kidney disease, liver disease, hormonal disorders and other illnesses can all cause gastrointestinal symptoms.

This is one reason it is important not to assume that vomiting is simply an upset stomach, particularly if it keeps happening.

What Causes Diarrhoea?

Diarrhoea occurs when faeces pass through the intestines too quickly or contain too much water. Like vomiting, it can have many different causes.

Common causes include:

• Dietary indiscretion, such as eating rubbish or table scraps

• Sudden changes in diet

• Food intolerance or sensitivity

• Parasites

• Bacterial or viral infections

• Stress or anxiety

• Inflammatory bowel disease

• Pancreatitis

• Certain medications

• Toxins

• Liver, kidney or other systemic diseases

  
  

Diarrhoea can range from a soft stool to frequent, watery bowel movements. You may also notice mucus or blood in the faeces.

When should I take my pet to the vet?

A single episode of vomiting or a small amount of loose stool in an otherwise healthy adult pet may sometimes settle without treatment. However, there are situations where veterinary advice is important.

Contact us if your pet:

• Is vomiting repeatedly

• Has persistent or severe diarrhoea

• Has blood in their vomit or faeces

• Has black, tarry-looking faeces

• Is unable to keep water down

• Refuses food

• Is unusually quiet, weak or lethargic

• Appears painful or has a swollen abdomen

• Shows signs of dehydration

• Has lost weight

• Has a history of another medical condition

• May have eaten a toxin or poisonous substance

• May have swallowed a foreign object

Puppies, kittens, elderly pets and pets with existing health problems can become unwell more quickly, so it is sensible to seek veterinary advice sooner rather than later.

What can I do while I wait for veterinary advice?

If your pet has mild gastrointestinal symptoms and is otherwise bright and comfortable, monitor them closely and make sure fresh water is available.

Do not give human medications unless our veterinarians have specifically advised you to do so. Some medications that are safe for people can be dangerous for dogs and cats.

It can also be helpful to keep a note of how often your pet is vomiting or passing diarrhoea, what it looks like and whether they are eating, drinking and behaving normally. If possible, take a photo of unusual vomit or faeces to show our veterinarians.

Our vets may recommend an examination, faecal testing, blood tests, X-rays, ultrasound or other investigations depending on your pet's symptoms and history.

Vomiting and diarrhoea are symptoms, not a diagnosis

There are many possible reasons why a dog or cat may vomit or develop diarrhoea. Sometimes the cause is relatively straightforward. Other times, these symptoms are the first indication of a more serious problem.

The most important things to consider are how severe the symptoms are, how long they have lasted and how your pet is otherwise behaving.

If you are concerned about your pet, it is always better to contact our veterinary team for advice. We can help determine whether your pet needs to be examined and how urgently they should be seen.

If your dog or cat is vomiting or has diarrhoea and you are concerned, please contact us for advice or to arrange an appointment.