Gastroenteritis in dogs – signs and what to do

Updated 2026-09-30 · 1 sources

Based on: PDSA

Book a vet visit

Book a vet appointment if you think your dog has this – a vet needs to confirm it and plan the treatment. Gastroenteritis is inflammation of the stomach and intestines.

What to do now

What you can do now

Contact your vet.
Note when it started, how often it happens and what else you see.
Take a photo or short video to show the vet.
Keep fresh water available.
Let your dog rest somewhere calm.

Don't

Do not give any human medicine.
Do not wait if it gets worse.

What it is

Gastroenteritis affects the stomach and intestines and can cause vomiting, diarrhoea, reduced appetite, lethargy and abdominal pain.^[1] It can range from mild to severe.^[1]

Signs

Diarrhoea
Vomiting
Reduced appetite or complete loss of appetite
Lethargy or low energy
A painful abdomen or tummy
Blood or mucus in the stool

Causes and risk factors

Bacteria, such as Campylobacter
Viruses, like parvovirus
A sudden change in diet
Worms and other parasites, such as Giardia
Ingesting inappropriate substances
Inflammatory Bowel Disease (IBD)
Food allergies
Organ disease, such as kidney or liver disease

How vets treat it

Antibiotics
Fluids or a drip
Hospitalisation
Anti-sickness medication
Medication

What the experts say

“Overview. Gastroenteritis is inflammation of the stomach and intestines, which causes symptoms such as vomiting, diarrhoea, reduced appetite, lethargy, and abdominal pain. Gastroenteritis varies in severity, from mild to severe.”
— PDSA [1]

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

OkPaw asks a few quick questions about your pet and tells you in 30 seconds whether it can wait. Free on Google Play for Android.

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Common questions

What is gastroenteritis in dogs?

Gastroenteritis is inflammation of the stomach and intestines.^[1]

What signs can gastroenteritis cause?

Signs can include diarrhoea, vomiting, reduced appetite or loss of appetite, lethargy, a painful abdomen, and blood or mucus in the stool.^[1]

When should I contact a vet?

Contact a vet if your dog's symptoms have not improved within 24 hours.^[1]

Sources

PDSA

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages