Signs of Dehydration in Dogs

What it usually means

Dehydration means your dog has lost more fluid than it has taken in. The AKC lists the usual signs as loss of skin elasticity, dry and sticky gums, thick saliva, sunken and dry-looking eyes, a dry nose, panting, reduced energy, loss of appetite, and vomiting with or without diarrhea. Dogs often eat less when dehydrated, which reduces the water they get from food and can make it worse.

The most common causes, roughly in order, are fluid loss from vomiting or diarrhea; hot weather and exercise with heavy panting; not drinking enough, from an empty or dirty bowl, a long car trip or a dog that dislikes its water; and fever or illness. Underlying conditions such as kidney disease and diabetes can cause dehydration even while a dog drinks a lot. Puppies, seniors, toy breeds and nursing mothers are at higher risk.

How to check your dog at home

Gum check: lift your dog's lip and touch the gums. They should be pink and slick. Dry, tacky or sticky gums suggest dehydration. Capillary refill: press a fingertip on the gum until it turns pale, then let go. The pink color should return within about two seconds; the AKC notes that a slower return suggests dehydration and poor circulation.

Skin tent test: gently lift a fold of skin over the shoulder blades and release. In a well-hydrated dog it springs straight back; in a dehydrated dog it falls back slowly or stays tented. Try these checks when your dog is healthy so you know its normal, because older dogs and wrinkly breeds naturally have looser skin.

When to call your vet today

Call your vet the same day if your dog shows dehydration signs and has vomited more than once, has had diarrhea for more than a day, will not drink or keeps water down only briefly, has eaten little for a day, or is a puppy, senior or small breed. Call too if your dog is drinking far more than usual and peeing a lot, because that pattern can point to kidney disease or diabetes rather than simple fluid loss.

A dog that seems mildly flat after a hot day out, but perks up, drinks well and shows normal gums within a few hours, can usually be monitored. If you are unsure, a quick phone call to your vet costs little and can tell you whether to come in.

When it's an emergency

Go to your vet or the nearest emergency vet immediately if your dog is very weak, collapsing, unresponsive or disoriented, has pale, gray-blue or very dry gums, a racing heart or very slow capillary refill, cold legs, or is vomiting repeatedly and cannot keep water down. The AKC describes dehydration with persistent vomiting, or with any suspicion of heat stroke, as a medical emergency.

Heat stroke signs include heavy, frantic panting, drooling, bright red or very pale gums, stumbling, vomiting and collapse, often after exercise or time in a hot car or yard. Move your dog to shade or air conditioning, offer small sips of cool water if it is alert, and travel to the vet with the air conditioning on. Do not use ice-cold water.

What you can safely do at home

For mild dehydration in a dog that is not vomiting, offer fresh, cool water in small, frequent amounts rather than a big bowl it might gulp and bring back up. Some dogs drink more from a clean bowl in a quiet spot, from a fountain, or when a little low-sodium broth with no onion or garlic is added. Ice cubes to lick can help a reluctant drinker.

Electrolyte solutions are sometimes used, but ask your vet first whether one is suitable for your dog and how much to offer; do not guess. Never force water into a dog's mouth, because it can be inhaled. Keep your dog cool and resting, and watch whether gums, energy and appetite improve over the next few hours.

What the vet will likely check

Your vet will examine gums, skin elasticity, eyes, heart rate and temperature to judge how dehydrated your dog is, and will want to know about vomiting, diarrhea, drinking, peeing and any heat exposure. Blood tests help measure the degree of dehydration and electrolyte balance and look for kidney problems, diabetes or other causes. A urine sample shows how concentrated the urine is.

Treatment replaces lost fluid, either under the skin for mild cases or through an IV drip for moderate to severe ones, and targets the cause, such as an infection, a stomach upset or heat stroke. Because dehydration is often a sign of something else, finding that cause is as important as the fluids.

Prevention

Always have fresh, clean water available, wash the bowl daily, and put out extra bowls in a multi-pet home or a large house. Bring water and a bowl on walks, hikes and car trips, and offer it regularly. In hot weather, exercise early or late in the day, provide shade, and never leave a dog in a parked car.

Watch intake when your dog is ill, and get help early for vomiting or diarrhea rather than waiting for dehydration to set in. Most dogs need roughly an ounce of water per pound of body weight a day, more when it is hot or they are active, so it helps to know roughly what your dog normally drinks.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.