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Signs of Dehydration in Dogs

signs of dehydration in dogs


Humans get headaches when we're dehydrated. It's our body's warning sign telling us we need to drink up. Dogs also get warning signs of dehydration, but it's up to us to interpret them. So, we can intervene before it's too late.

A dehydrated dog is in danger of long-term physical consequences. And, in the worst cases, death.

Our dogs' bodies are 80% made up of water. (That's higher than us – our bodies are 60% water.) Water is necessary for nearly every important function in their bodies. From regulating body temperature and keeping their pH levels balanced. To lubricating joints and aiding in digestion.

It's also essential to the maintenance of healthy levels of electrolytes like potassium, chloride, and sodium, which your dog can't live without.

A loss of 10 to 15% of the water in your dog's body is enough to cause severe dehydration, which can lead to shock, kidney failure, and death.


Warning Signs of Dehydration in Dogs

The signs of a dehydrated dog will vary depending on how dehydrated your dog is.

Early-stage signs include lethargy and excessive panting. Later-stage signs include muddled thinking, an inability to walk, and unconsciousness. Other dog dehydration symptoms can be more subtle.

Here's a list of the most common warning signs of dog dehydration.


Panting/Fast Breathing
Overheated, dehydrated dogs will pant excessively to try and cool themselves down. In the latter stages of dehydration, the panting may be replaced by fast, staccato-like breathing (often accompanied by a racing heart rate).
Dry Nose
A dog's nose should always be moist. If your dog's nose is dry, cracked, or flaky, there's a good chance he's dehydrated. Probably, for some time.
Sunken Eyes
Eyes that look like they've sunk into the skull are one of the most immediately detectable signs of severe dehydration in dogs.
Dry Gums
Aren't your gums always moist? Same thing for your pup. If you suspect your dog may be dehydrated (maybe you noticed other signs), lift up your dog's lips and touch his gums. If they're dry or sticky, he needs water. 
A dehydrated dog's gums will also turn white and stay that way if you press on them, rather than returning to pink or red.
One note: Like people, dogs can sleep with their mouths open and this will often result in a dry mouth (and gums). If your pup's gums seem dry right after a nap, that's normal. Keep an eye on her to ensure they're not still dry a few hours later.
Loose Skin
A surefire sign of dehydration in dogs is loose, nonelastic skin.
Not sure what we mean? Grab a handful of the skin from the back of your dog's neck or on his back and lift. Then release. Does it snap back into place? Or does it stay in a pinched position (also called a skin tent)?
The skin on a hydrated dog falls quickly back into place. Anything else is a sign of dehydration. How long the skin lingers in that pinched position tells you how dehydrated he is.
(This is NOT true of dogs with lots of wrinkles like Sharpes and Bulldogs. For them, you'll need to look for other signs)
Dark Urine
This is another symptom of dehydration you'll find in people too. The more dehydrated your dog, the darker the urine will be.
Sluggishness/Dulled Mental Activity
The more dehydrated your dog is, the more he will slow down. Both physically and mentally. He may walk slower than normal, appear unsteady on his feet, or even be too weak to stand up.

How To Rehydrate a Dog

Most dogs can go without water six to 10 hours. After that, they'll start to feel the effects of dehydration. But you might not notice any signs for up to 24 hours.

In other words, by the time you notice your dog is dehydrated, it may have been a while. You'll need to get your pup rehydrated pronto.

To rehydrate a mildly dehydrated dog, start by offering small sips of water every few minutes or offer pieces of ice for him to lick.

If you've got any moisture-rich treats, bring them into the mix. Don't go too fast. Too much water, too quickly while dehydrated could cause vomiting, which will only make matters worse.

This is also how you should rehydrate your dog during strenuous hikes or runs. Or after a long game of fetch in the sun.


Depending on how long your dog has been without water, this may be enough. Do another skin test to see if anything has changed and call your vet if nothing seems to be happening.

If the signs of dehydration are extreme (your dog's eyes are deeply sunken, he can't stand up or is barely conscious) you'll need to take him to the vet immediately. Your vet will put your pup on a drip, which will replace the fluids he's missing, as well as the vital electrolytes his body needs to keep functioning.

In mild cases, your vet may inject fluid under your dog's skin, which will be absorbed over a period of a few hours.


Causes of Dehydration in Dogs

In the summer months, high temperatures and lack of water are the top causes of dehydration in dogs. Lots of running around in the heat can also cause your dog to become overheated and dehydrated.

(Dogs are at such high risk of dehydration in summer that pet product manufacturer Pet Safe declared July Pet Hydration Awareness Month.)

Other causes of dehydration in dogs can include excessive vomiting and diarrhea (these also speed up the rate of dehydration), heatstroke, and illnesses such as kidney disease and diabetes.

Puppies, senior dogs, and nursing mother dogs are also at increased risk of dehydration.

Some dogs simply stop drinking. This is almost always a sign of illness. Take your pup straight to the vet if he stops drinking, both to prevent dehydration and to address the underlying cause.


Keeping Your Dog Hydrated

The best way to ensure your furry best friend stays hydrated is to keep a regular supply of fresh, clean water on hand. That includes whenever you're heading out the door with your pup, especially if it's hot outside.

But how much water should your dog be drinking?

It's simple. Your dog needs approximately one ounce of water for every pound of body weight. 

Your seven-pound Maltese? She needs seven ounces of water. Your 50-pound Bulldog? She needs 50 ounces. The math couldn't be easier.

To ensure your dog is getting the necessary amount of water, measure her water bowl to see how often you need to fill it up.