Managing chronic vomiting and diarrhoea in dogs

This article provides a practical approach to canine vomiting and diarrhoea, distinguishing acute vs. chronic presentations. It guides prioritizing differential diagnoses based on breed, history, and exam findings (gastrointestinal (GI)/extra-GI), and outlines a logical diagnostic pathway for effective patient management.

A presentation of vomiting and/or diarrhoea is a common occurrence in veterinary practice. As the cause and management may differ between acute and chronic diarrhoea, consideration for the duration of clinical signs should be given, with chronicity generally defined as signs that are persistent for at least 14–21 days. Clinical signs can also be intermittent, or can wax and wane.

It is important to distinguish vomiting from regurgitation to the best of your ability with careful questioning of the owner or even asking the owner to obtain a video of the event.  Diarrhoea may otherwise be observed as any change to the fluidity, frequency or volume of faeces produced.

Formulating and Prioritizing Differential Diagnoses

Prioritization of these differential diagnoses will be based on:

• Specific breed syndromes
• Environmental factors
  • Example: a young dog from a shelter environment may be more likely to have infectious / parasitic disease. 
• Clinical history 
  • Example: a dog with a known history of pancreatitis that then develops diarrhoea and weight loss would prioritise EPI over, for example, neoplasia.
• Chronicity
  • Example: a long duration of clinical signs (months) would make a neoplastic disease less likely.
• Physical examination
  • Example: abdominal distension and diarrhoea, would be suspicious of protein-losing enteropathy.

A logical organisational approach to vomiting and diarrhoea usually considers differentials grouped as either extra-gastrointestinal (Box 1) or primary gastrointestinal (Box 2).  For the former an ‘organ system’ approach is helpful, whilst for the latter differentials are usually approached using DAMNIT-V or a similar acronym.

Physical examination findings will also be important in formulating a prioritized list of differentials. Some of the conditions listed below might be accompanied by other clinical signs that are more relevant than the vomiting and the diarrhoea.

Box 1. Differential diagnoses for extra-gastrointestinal diseases causing vomiting and/or diarrhoea in dogs.

Box 2. Differential diagnoses for primary gastrointestinal disease.

Formulating a Logical Diagnostic Approach

• Severity of clinical signs, physical examination and laboratory findings
• Owner’s financial limitations
• Differential diagnosis list specific to the patient
• Available resources (e.g. access to ultrasound or endoscopy equipment, whether referral to a specialist is available)

Determining when a more intensive diagnostic approach is needed

• There is marked weight loss
• There is severe hypoalbuminaemia
• There is a palpable abdominal mass
• There is gastrointestinal bleeding
• There is a suspicion of biliary tract obstruction
• There is a suspicion of gastrointestinal obstruction
• The clinical signs are severe and not improving with supportive treatment

References

Jergens AE, Crandell JM, Evans R, Ackermann M, Miles KG, Wang C. A clinical index for disease activity in cats with chronic enteropathy. J Vet Intern Med. 2010 Sep-Oct;24(5):1027-33. doi: 10.1111/j.1939-1676.2010.0549.x. Epub 2010 Jun 24. PMID: 20584141.

Allenspach, K., Wieland, B., Gröne, A. and Gaschen, F., Chronic Enteropathies in Dogs: Evaluation of Risk Factors for Negative Outcome. J Vet Intern Med. 2007; 21: 700-708. doi: https://doi.org/10.1111/j.1939-1676.2007.tb03011.x