Gastroenteritis is a nonspecific term to describe an inflammation of the digestive tract (gut or stomach/intestine) and is often characterised by a sudden onset of vomiting and diarrhoea. If the problem is limited to vomiting, it may be termed gastritis, and if only diarrhoea, enteritis.
Uncomplicated gastroenteritis is often caused by eating spoiled or contaminated food, and dogs are more likely to be affected due to their tendency to scavenge. Frequently the real cause of the gastroenteritis remains unknown and the majority of pets will be treated successfully with symptomatic and supportive treatment. This may involve supporting the animal by providing fluid therapy, for example, and treating symptoms such as vomiting.
Some specific causes of gastroenteritis include ingestion of foreign bodies, toxins, plants, irritant drugs, intestinal parasites, viruses (e.g. parvovirus) or bacteria. In such cases, a specific diagnosis of the cause may be made after performing specific tests.
Haemorrhagic gastroenteritis is a more serious type, in which blood can be seen in the vomit and/or faeces. The cause is often unknown, but rapid supportive treatment is required
Gastroenteritis will often come on rapidly and is characterised by a sudden onset of vomiting and/or diarrhoea. Food and bile are typically vomited; although small amount of blood may also be present. Affected pets are usually not interested in food and may feel unwell. Fever and abdominal pain are uncommon.
You should consult your vet if your dog shows signs of gastroenteritis. Advice should definitely be sought when the following symptoms are present:
persistent or intense vomiting (more than 2-3 times per day)
loss of appetite
pink vomit or red/black stools
A potentially serious complication of vomiting and diarrhoea is dehydration. This can occur quite quickly, be very dangerous to the pet’s health and, if left untreated, lead to death - especially in young animals.
Mild gastroenteritis can usually be diagnosed on clinical signs of vomiting and/or diarrhoea. The veterinary surgeon will conduct a full clinical examination and will be particularly interested in any relevant information that the owner may have on the dogs activity over the previous days.
If there is a clinical suspicion of more than an uncomplicated gastroenteritis, or if an underlying cause is suspected, then further tests may be required to determine the cause. These may include abdominal radiographs (x-rays), abdominal ultrasound, blood or faecal tests (e.g. to diagnose intestinal parasites or viral disease such as parvovirus infection in puppies).
Blood tests are often required to determine if there is any disease of other organs and to assess the hydration state of the animal
Treatment of acute gastroenteritis relies almost solely on supportive care and medication that treats the symptoms (e.g. vomiting and diarrhoea). Controlling the vomiting and diarrhoea is a key priority to prevent loss of fluid and salts as this can lead to dehydration and can rapidly become life-threatening.
Antiemetics are medications that treat vomiting and your veterinary surgeon may choose to administer and prescribe these if appropriate. Other supportive treatment includes the administration of balanced salts and fluid (called ‘fluid therapy’). This can be given orally if the animal is not vomiting, or by intravenous infusion (a ‘drip’).
A short period of starvation followed by reduced amounts of bland food might also be prescribed by the veterinary surgeon. If an underlying cause can be found, this should also be treated specifically if possible – for example, medication to kill intestinal worms.
Most non-specific gastroenteritis cases can be managed within a few days, providing fluid loss is controlled and or replaced. It is essential to monitor your pet’s condition during the treatment at home. If there is no improvement or if there is any deterioration (e.g. blood in the motion, increased lethargy, weakness, fever, etc.), then you should contact your veterinary surgeon without delay
Dogs are scavengers by nature, but should be discouraged from doing so from an early age if possible. Consult your veterinary practice or behaviourist for help to achieve this. Your dog may not tolerate a sudden change of diet, thus it is essential to introduce any new diet over several days or weeks.
Vaccinating your pet regularly will also protect them against several serious viral diseases that affect the gastrointestinal tract – (such as parvovirus infection).
Finally regular ‘de-worming’ (also known as “worming”) at least 4 times a year with a broad spectrum intestinal worming preparation, together with flea control to prevent some intestinal worms (e.g. Dipylidium), is essential.