Dr Felicity delves into the causes, symptoms and treatment of tummy upsets in dogs.

What causes gastrointestinal upsets?
Gastrointestinal upsets are quite common in dogs. These illnesses usually manifest with vomiting, diarrhoea or both. Affected dogs will often appear flat or generally unwell. They may refuse to eat (especially if they are nauseous) and they may develop other clinical signs like an elevated temperature. Dogs with diarrhoea alone may not seem unwell at all and continue to eat and behave normally.

Many gastrointestinal upsets in dogs are mild, resolve quickly and do not require veterinary attention. The cause of an upset is often not determined but is most commonly the result of a dog eating something unusual like a dead animal, animal faeces, or spoiled or contaminated food. The consumption of the contents of the kitchen bin is a common source of gastrointestinal upsets in dogs. It can be almost impossible to work out what a dog has eaten to become unwell, especially for dogs that spend time outside unsupervised.

When bacteria cause an upset tummy, there can be a delay of six to 24 hours or more between the consumption of the problematic food and the onset of vomiting or diarrhoea. While the most recent meal may be the source of the problem, it is also very possible that something eaten less recently has been the issue. The amount of time it takes for a tummy upset to develop depends on which bacteria types have been consumed.

Some dogs experience tummy upsets when they eat normally safe foods to which they are sensitive or allergic. There are also some foods that are known to be toxic to dogs and should always be avoided.

Gastrointestinal upsets can also be the result of viral infections or exposure to toxins, including toxic plants and garden pesticides. Also, when a dog has a foreign body, for example a sock, lodged in their stomach or intestines they may seem like they have an upset tummy before becoming very unwell.

Serious disorders like pancreatitis, hepatitis, renal failure and meningitis can all potentially have associated gastrointestinal signs of vomiting, diarrhoea or both.

When do I call the vet?
It can be hard to know how long to wait before calling the vet if your dog has vomiting and diarrhoea. Any dog that seems depressed or lethargic should be seen by a vet, even if it has only vomited once or twice.

It is always best to treat unwell animals early as medical therapy will usually be beneficial, whereas waiting until an animal is extremely unwell can reduce its chances of making a full recovery from its illness (and always results in a bigger vet bill).

Generally, if a dog vomits once and seems bright and happy there is no need to panic. Similarly, one bout of the runs is not an emergency providing the dog seems otherwise well.

If mild clinical signs do not resolve within 12 hours or if in doubt at all, get your dog checked out. Any vomiting that is frequent or severe should be addressed as soon as possible to prevent complications that are more difficult to treat like oesophagitis and gastric ulceration.

If blood is seen in either vomit or faeces then it’s time to call the vet. Animals that vomit frequently are usually also unable to drink water and will dehydrate very quickly which can become life-threatening in some cases. Generally, very young and very old dogs will dehydrate and deteriorate faster than the average adult dog.

How is a gastrointestinal upset treated?
Prompt treatment is important to ensure the best possible outcome for a sick dog. In some cases gastrointestinal upsets will require blood work and imaging to rule out more serious conditions involving other organs.

Many cases will respond well to supportive therapy including medication to stop vomiting, gastro-protectants and sometimes antibiotics. Most animals that have been unable to eat or drink for a period of time will benefit from intravenous fluids in hospital. The cause of the illness is usually not determined except occasionally when contaminated food, specific toxins or intestinal foreign bodies can be positively identified.

Will my dog need a special diet?
Many dogs will respond well to a bland diet, for example boiled chicken breast and white rice, for a few days. This type of food is easy to digest and when fed in small amounts a few times a day, allows the gastrointestinal system to recuperate. Once the illness has passed, normal food can usually be slowly reintroduced over a few days.

If the upset has been a result of a food intolerance, your vet may recommend a special hypoallergenic diet and may discuss completing a food trial to try and determine the food that is causing the problem.