Sudden Diarrhoea: How Common It Is, and What UK Vets Actually Do
About 1 in 12 UK dogs saw a vet for sudden diarrhoea in 2019. Most needed one visit, but 38% got antibiotics despite guidance against routine use.
Written by thecanineledger
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If your dog has diarrhoea and is also vomiting repeatedly, very quiet, not drinking, has a lot of blood in the stool, or is a young puppy or an elderly dog, call your vet the same day.
Our note: This advice is ours. This study gives no owner advice.
In UK vet records from 2019, an estimated 8.18% of dogs were seen for sudden (acute) diarrhoea, about 1 in 12 (O’Neill et al., PLoS One 2025). Most needed only one visit. However, 38.20% of dogs in the sample were given antibiotics.
While antibiotics were common, the authors say this goes “against years of recommendation to the contrary”. Our separate page looks at what the trials show.
→ Does Diarrhoea Need Antibiotics? What the Evidence Says
1. The study
The dogs. Researchers used VetCompass, a database of anonymised UK primary-care records, covering 2,250,417 dogs. They checked a random sample of possible cases by hand and confirmed 1,835.
Funding. The Kennel Club Charitable Trust and a pet insurer supported the work.
Our note: We found no competing-interests statement in the text we extracted.
2. What the dogs had
| Sign alongside diarrhoea | Share of dogs |
|---|---|
| Vomiting | 44.25% |
| Reduced appetite | 27.68% |
| Lethargy | 24.20% |
| Blood in the diarrhoea | 29.32% |
Age. Dogs under 3 and over 9 were more likely to be seen than middle-aged dogs. The authors link young dogs’ risk to scavenging.
Breeds. Maltese, Miniature Poodles, Cavapoos, German Shepherd Dogs, Yorkshire Terriers and Cockapoos had higher odds than crossbreeds.
3. What vets did
| Management | Share of dogs |
|---|---|
| Probiotics | 59.62% |
| Diet changes | 43.98% |
| Antibiotics | 38.20% |
| Anti-sickness medicine | 24.03% |
| Admitted to hospital | 7.19% |
One visit. 80.27% had only one visit for the episode.
Blood drove antibiotic use. The authors found blood in the diarrhoea “appeared to be a strong driver of antibiotic prescription”, which they say contradicts current recommendations.
Our note: The paper reports probiotic use but doesn’t assess whether probiotics work.
4. What the study can’t tell you
One visit isn’t proof of recovery. The abstract says 80% of dogs were “not receiving a second veterinary visit”. The conclusion says “not requiring” one. Those aren’t the same. Some owners may have gone elsewhere or managed at home.
Severity. The records didn’t allow the authors to judge how ill each dog was.
Older data. The data are from 2019. The authors note that many UK practice groups have since brought in new antibiotic guidelines.
Our note: Asking whether antibiotics are needed is our suggestion.
→ Vomiting and Diarrhoea: When It Can Wait and When It Can’t · → “Finish the Course”: Antibiotics for Dogs
5. What we could not verify
| Commonly said | What we found |
|---|---|
| “Diarrhoea always needs antibiotics” | No. The authors say antibiotics are discouraged for routine use. |
| “Blood in diarrhoea means antibiotics” | Not according to current recommendations, the authors say. |
| “Most dogs get better after one vet visit” | Not proven. Most had one visit, but recovery wasn’t measured. |
Sources
- O’Neill DG, Prisk LJ, Brodbelt DC, Church DB, Allerton F. Epidemiology and clinical management of acute diarrhoea in dogs under primary veterinary care in the UK. PLoS One 2025: VetCompass study, 2019, 1,835 confirmed cases. Supported by the Kennel Club Charitable Trust and a pet insurer
Always confirm with your vet before acting on anything on this page.