Published: 11 Jun 2025 | Last Updated: 12 Jun 2025 14:40:24

New research from the Royal Veterinary College’s (RVC) VetCompass Programme has revealed scavenging, digestive diseases and gastroenteritis as some of the most common causes of diarrhoea amongst dogs in the UK. The study sheds light on how frequently the condition occurs in different breeds, as well as on commonly used veterinary treatments and aims to help owners understand the condition more.

Diarrhoea is a common occurrence in dogs across the UK. The high frequency and often severity of this illness makes it one of the most important welfare conditions that owners and veterinarians need to effectively manage.

Conducting this research, the RVC team analysed anonymous veterinary records of more than two million UK dogs attending primary veterinary care practices during 2019. The findings revealed that one in 12 (8.18%) of all dogs in the UK suffer from acute diarrhoea that needs veterinary care at least once each year. It also found that, of the more than 1,000 dog breeds in the UK, Cavapoo, Maltese, Miniature Poodle, German Shepherd Dog, American Bulldog and Rottweiler had the highest risk of acute diarrhoea.

The researchers also determined that the most common reasons for acute diarrhoea were scavenging, underlying gastroenteritis and other digestive diseases, reactions to specific medications and sudden dietary changes. These findings highlight that owners can reduce the risks of diarrhoea by avoiding sudden changes or novelty in their dog’s diet. The motto from Dr Dan O’Neill, Associate Professor of Companion Animal Epidemiology at the RVC and lead author of the study, is that consistent diet leads to consistent poo.

Additionally, the study found that almost 4-in-10 cases (40%) of acute diarrhoea received antibiotic treatment. This is despite recent research showing no clinical benefits to antibiotic usage in acute diarrhoea recovery. In fact, unnecessary use of antibiotics can cause tummy upsets in dogs and place both dogs and humans at increased risk of future antibiotic-resistant infections. This demonstrates the need for further efforts to raise wider awareness on when it is and when it is not appropriate to use antibiotics. Alternatively, the use of bland diets with or without probiotics may be a sensible initial approach and owners should always seek veterinary advice if they are concerned.

Other key findings of the study include:

• The risk of acute diarrhoea was higher in young (under 3 years) and more aged (over 9 years) dogs than in middle-aged dogs.
• Alongside the diarrhoea itself, affected dogs commonly also showed vomiting, reduced appetite and/or lethargy.
• Almost a third (29%) of acute diarrhoea cases were reported to have blood in the diarrhoea. Bloody diarrhoea cases were more likely to be prescribed antibiotics than non-bloody diarrhoea (59% vs 30%).
• Short-skulled breeds were linked to a lower risk of acute diarrhoea, whereas long-skulled breeds had a higher risk of acute diarrhoea compared to normal-skulled breeds
• The majority of acute diarrhoea cases resolve within two days following veterinary treatment. Fewer than 20% of acute diarrhoea cases required a second veterinary visit, suggesting that owners of affected dogs should feel confident that most dogs will successfully recover with the correct treatment.

Dr Dan O’Neill, Associate Professor of Companion Animal Epidemiology at the RVC and lead author of the paper, said:

“Experiencing the dreaded doggy poonami is one of those events every dog owner fears. This new study shows that diarrhoea events are very common in dogs but that owners should not panic – no matter how bad the deluge, most dogs will recover in a few days with good veterinary treatment.”

Dr Fergus Allerton, veterinary internal medicine specialist and co-author of the paper, said:

“The outcomes reported here are very reassuring. They represent yet another reminder that antibiotic therapy is an unnecessary component of diarrhoea management. Pet owners are a key stakeholder in diarrhoea consultations. This study should help improve recognition of salient risk factors and support appropriate management without recourse to antibiotics.”

Dr Lauren Prisk, primary-care veterinary surgeon and co-author of the paper, said:

“This report is continuing to open the discussion between owners and vets in primary care practice in responsible antibiotic use. This new study should reassure vets as well as owners when deciding to manage these acute diarrhoea episodes conservatively without antibiotics unless really indicated.”

Notes to Editors

Reference

O'Neill, D.G., Prisk, L., Brodbelt, D.C., Church, D.B., Allerton, F. (2025) ‘Epidemiology and clinical management of acute diarrhoea in dogs under primary veterinary care in the UK’. PLOS ONE, available: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0324203

The full paper can be accessed at: DOI 10.1371/journal.pone.0324203

URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0324203

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About the RVC

• The Royal Veterinary College (RVC) is the UK's largest and longest established independent veterinary school and is a Member Institution of the University of London. 
• It is one of the few veterinary schools in the world that hold accreditations from the RCVS in the UK (with associated recognition from the AVBC for Australasia, the VCI for Ireland and the SAVC for South Africa), the EAEVE in the EU, and AVMA (probationary) in the USA and Canada. 
• The RVC is ranked as the top veterinary school in the world in the QS World University Rankings by subject, 2025. 
• The RVC offers undergraduate and postgraduate programmes in veterinary medicine, veterinary nursing and biological sciences. 
• The RVC is a research-led institution, with 88% of its research rated as internationally excellent or world class in the Research Excellence Framework 2021. 
• The RVC provides animal owners and the veterinary profession with access to expert veterinary care and advice through its teaching hospitals and first opinion practices in London and Hertfordshire.