Dehydration in dogs: the signs, two home checks, and what to do
Short answer
The main signs of dehydration in dogs are dry or tacky gums, skin that is slow to fall back when you lift it, sunken eyes, thick saliva, dark urine and low energy. You can check two of them at home in under a minute. Mild cases: offer small amounts of fresh water often. If your dog won't drink, keeps vomiting, has diarrhea, or seems weak, go to a vet now.
Signs of dehydration in dogs
Early signs
- Gums that feel tacky or dry instead of wet and slick
- Thick, ropey saliva
- More panting than the weather or exercise explains
- Peeing less, or darker yellow urine
- Less energy and less interest in food
Moderate to severe signs
- Skin on the back of the neck stays up, or falls back slowly, after you lift it
- Sunken, dull-looking eyes
- Gums slow to turn pink again after you press them
- Weakness, wobbliness or collapse
- Fast heart rate, cool paws or ears
How vets grade dehydration
Vets estimate dehydration as a percentage of body weight lost as water. The visible signs only show up once a dog is already about 5% dehydrated, which is why catching the early signs matters.
| Estimated loss | What you see |
|---|---|
| Under 5% | Nothing obvious. Your dog may just drink more. |
| 5 to 6% | Tacky gums, thicker saliva |
| 6 to 8% | Skin slow to fall back, gums slower to refill, dry mouth |
| 8 to 10% | Clearly slow skin, sunken eyes, dry gums |
| 10 to 12% | Skin stays tented, signs of shock: weak pulse, cold legs, collapse |
| Over 12% | Life threatening. Emergency treatment needed. |
Two checks you can do at home
1. The skin tent test
Gently lift a fold of skin between your dog's shoulder blades and let go. In a well-hydrated dog it snaps straight back. If it falls back slowly, or stays up like a little tent, your dog is dehydrated. Older and very thin dogs have less elastic skin, so compare the result with what your dog's skin does on a normal day.
2. The gum and capillary refill test
Lift your dog's lip. Healthy gums are pink and wet. Press a fingertip on the gum until the spot turns pale, then let go. The color should come back within about 2 seconds. Dry, sticky gums or a slower return point to dehydration. Very pale, grey or bright red gums need a vet straight away.
What causes dehydration in dogs
- Not drinking enough: stale or dirty water, an empty bowl, travel, a new home, or a bowl that's hard to reach
- Heat and exercise: panting uses up water quickly, especially in flat-faced breeds
- Vomiting and diarrhea: the most common cause of fast dehydration
- Fever and illness
- Underlying conditions: kidney disease and diabetes make dogs lose water faster
- Some medications, such as diuretics
How to rehydrate a dog with mild dehydration
- Offer small amounts often. A few sips every few minutes works better than a full bowl. A dehydrated dog that gulps a lot at once may throw it back up.
- Try ice cubes or ice chips if your dog won't drink from the bowl.
- Move your dog somewhere cool and shaded and let it rest.
- Add water to food, or offer a little wet food.
- Ask your vet before giving any electrolyte product. Skip sports drinks and flavored drinks.
If your dog isn't clearly better within a few hours, or gets worse, call your vet. Vets can give fluids under the skin or through an IV, which works far faster than drinking.
When dehydration is an emergency
Go to a vet now if your dog:
- won't drink at all, or vomits everything it drinks
- has had vomiting or diarrhea for more than 24 hours (sooner for puppies, seniors and small dogs)
- has dry, pale or grey gums, or gums that take more than 2 to 3 seconds to refill
- has skin that stays tented
- is weak, wobbly, confused or has collapsed
- is panting heavily and drooling with bright red gums after heat. That can be heatstroke.
How to prevent dehydration
- Keep fresh water available all the time, and change it at least once a day
- Bring water on walks and offer it the moment you get home
- Give extra water and shade on hot days
- Know your dog's normal intake. Our water-by-weight chart shows the target and how to measure it.
- Make water appealing. These 12 ways to get your dog drinking more start with the bowl itself.
Fresh water is the part most homes get wrong without noticing. A bowl topped up all day still holds yesterday's water. The Crunchy Fountain drains its stainless tray into a sealed used-water tank and refills it from a separate clean tank every 6, 8 or 12 hours. If your dog empties it in between, it refills within 2 hours on its own. No filter, nothing to reorder.
Quick answers
How can I tell if my dog is dehydrated?
Lift the skin between the shoulder blades. If it doesn't snap straight back, and the gums feel dry or sticky, your dog is likely dehydrated.
How fast can a dog get dehydrated?
Within hours on a hot day, during heavy exercise, or with vomiting and diarrhea. Puppies and small dogs dehydrate fastest.
Can I give my dog Pedialyte?
Ask your vet first. Some vets approve an unflavored pediatric electrolyte solution for mild cases, but flavored versions and sports drinks are not a good idea, and a dog that can't keep fluids down needs a vet, not a drink.