Dog Health
Why Is My Dog Not Drinking Water? UK Dehydration & Thirst Guide
Published Last updated 4 min read
Quick answer
Healthy dogs drink regularly throughout the day. Brief refusal after stress, travel, or mild tummy upset may resolve quickly. No water for 24 hours, or any refusal paired with vomiting, lethargy, or sticky gums risks dehydration — phone your vet, especially in puppies, seniors, and small breeds. Wet food helps but does not replace water.
How much water is normal?
Most dogs drink roughly 50 ml per kg body weight daily — more in hot weather or after exercise. Individual habits vary: some visit the bowl often; others drink large amounts at once. Know your dog's normal pattern so you notice change early.
| Dog size | Approximate daily intake |
|---|---|
| Small (5 kg) | 250 ml+ |
| Medium (15 kg) | 750 ml+ |
| Large (30 kg) | 1.5 litres+ |
Dogs on wet food drink less than kibble-fed dogs — this alone is not illness. Sudden refusal always matters.
Common causes of reduced drinking
Nausea and gastrointestinal illness
Dogs vomiting or with diarrhoea often refuse water even when dehydrated — a dangerous combination. Pancreatitis, dietary indiscretion, and infections are common triggers.
Mouth and dental pain
Broken teeth, dental abscesses, gum disease, or foreign bodies make drinking painful. Watch for drooling, pawing at the mouth, or favouring one side when chewing.
Fever and systemic illness
Kidney disease, liver disease, and infections reduce appetite and thirst — or cause odd patterns. If your dog was drinking excessively before stopping, see Dog drinking excessive water — diabetes and kidney problems often start with increased thirst.
Stress and environmental change
Boarding, moving house, new pets, or loud events can temporarily suppress drinking. Ensure a quiet bowl location and familiar water source.
Behaviour and preference
Some dogs dislike metal taste, bowl location, or stale water. Clean bowls daily. Senior dogs with cognitive dysfunction may forget where the bowl is.
Dehydration signs to watch for
According to the PDSA, dehydration signs include:
- Sticky or dry gums — normal gums are moist and slick
- Skin tenting — gently lift skin on the neck; slow return suggests dehydration
- Sunken eyes and dry nose
- Lethargy, weakness, or collapse
- Thick saliva or excessive drooling
- Dark, strong-smelling urine or very little urination
Pale gums suggest a different emergency — see Pale gums in dogs.
When to see a vet urgently
Contact your vet immediately if:
- No water for 24 hours or you are unsure when they last drank
- Vomiting or diarrhoea plus not drinking — puppies dehydrate within hours
- Lethargy, collapse, or wobbliness
- Known toxin ingestion or heat exposure
- Pain — crying, hunched posture, bloated abdomen
- Diabetic dog missing meals and water — risk of crisis
Same-day care is wise for seniors and small breeds refusing water more than 12 hours.
Home monitoring and safe encouragement
Track intake:
- Measure water bowl level at the same time each day
- Note urine frequency on walks
- Record vomiting, appetite, and energy
Safe ways to encourage drinking:
- Fresh cool water — change twice daily; wash bowl
- Multiple bowls in quiet locations
- Ice cubes in water on hot days — see Can dogs eat ice cubes UK?
- Low-sodium chicken stock (no onion or garlic) — small amount mixed with water
- Wet food or water added to kibble if eating normally
What not to do:
- Do not force water into the mouth if your dog is vomiting or unconscious — aspiration risk
- Do not give milk — many dogs are lactose intolerant
- Do not delay vet care waiting for tricks to work if dehydration signs are present
- Avoid human electrolyte drinks unless your vet advises
What your vet may do
Examination checks hydration, temperature, mouth, abdomen, and heart. Blood and urine tests identify kidney, liver, and metabolic disease. Treatment may include subcutaneous or intravenous fluids, anti-nausea medication, and treating the underlying cause.
Related guides
Sources & further reading
Facts in this guide are rewritten in plain English from publicly available UK advice. We name the organisation where a specific point comes from their guidance. Links below go to the original pages — use them to read the source material directly.
PETHEALTH+ is independent. These organisations do not sponsor, approve, or partner with this website. Guidance checked against sources listed below (last updated 2026-06-25).
Related guides
- Dog Vomiting: Common Causes, Home Care & When to Call the Vet
- Dog Diarrhea: 8 Safe Home Remedies (and 2 That Are Dangerous)
- Pancreatitis in Dogs: Symptoms, Diet & Recovery
- Dog Dental Care UK — Brushing, Gum Disease & Vet Checks
- Why Is My Dog Drinking So Much Water? UK Causes & When to Worry
- Cognitive Dysfunction in Dogs UK — Canine Dementia Signs & Care
Frequently Asked Questions
- How long can a dog go without water before it is dangerous?
- Beyond 24 hours without drinking warrants a vet visit. Puppies, small breeds, and dogs with vomiting or diarrhoea dehydrate faster — sometimes within hours. Offer water but do not force it if your dog is vomiting repeatedly.
- Can wet food replace drinking water?
- Wet food contributes to hydration but does not replace free access to fresh water. Dogs on wet food still need a water bowl — reduced drinking on wet food alone may still signal illness.
- Why won't my dog drink after surgery or anaesthesia?
- Nausea from anaesthesia and pain are common. Offer small amounts of water once your vet allows oral intake. Call your vet if refusal continues beyond their expected recovery window or if vomiting occurs.
- My dog drinks loads normally — could illness cause the opposite?
- Yes — some dogs drink excessively before later refusing water when very unwell. Sudden changes in either direction matter. See excessive drinking guide if thirst was high first.