Acute gastroenteritis is common in dogs, yet its various causes and the evidence for different treatments are still uncertain. This presentation will discuss what we know so far and what is considered the optimal treatment.

Acute vomiting and diarrhoea in dogs are common presenting problems and the term “acute gastroenteritis” implies signs occur contemporaneously or sequentially, i.e. vomiting leads to profuse diarrhoea, which leads to mucoid diarrhoea. Although often described as ‘gastroenteritis’, not all cases involve inflammation. Once surgical conditions are ruled out, most cases are probably due to viruses or toxicities. Yet this is not an issue as often a definitive diagnosis is not required: mild cases are usually self-limiting and require no treatment or symptomatic treatment with anti-emetics, anti diarrhoeals and dietary modification.

More severe cases are at risk of dehydration and fluid therapy is the most important, but non-specific treatment. Yet an incorrect assumption that bacterial enteritis is common leads to frequent, unjustified use of antibacterials. Paradoxically, parvovirus infection is probably the main indication for using antibacterials because, as well as mucosal damage allowing bacterial translocation, the patient is often immunosuppressed.