Dehydration in Dogs: What Every Owner Needs to Know

Water, deadly stuff. Too much of it and the dog drowns. Not enough and they become dehydrated. It is indeed ironic that water, which is so essential to life, can be fatal in the wrong quantities.

OK, so perhaps the dangers of drowning are obvious, but what about the other extreme, when there is a lack of water and the dog becomes dehydrated?

Why Dehydration Can Be Deadly

Around 60-70% of a dog is water! But this is dynamic water, whizzing round in the blood stream, plumping up cells, being excreted by the kidneys, and replaced by the moist food and drinking water.


When replacement water is not available, the body adapts. The kidneys recycle water from the bloodstream and body tissues become more concentrated. This is great in the short term, but in the long term causes toxins to build up and complications with organ function.


Taken to its ultimate end, dehydration thickens the blood, reduces the circulation to the organs, causes toxin buildup, and creates microclots which clog up the lungs and organs causing death. Quite simply, the body cannot function for more than a few days without water.  


Dehydration isn't an all-or-nothing condition and can range from mild to extreme. However, it is crucial to recognize the tell-tale signs early, so you can set about correcting the condition.

Signs of Dehydration

It's a simple equation: If the dog loses more water than they take in, they become dehydrated. Thus, some dogs are at greater risk than others, for example the vomiting dog that can't keep fluid down or the diabetic dog that produces lots of urine. These dogs lose a lot of water and if they don't drink, will quickly dehydrate.


Alternatively, a normal dog on a hot day loses heat by panting and the evaporation of saliva. This increased loss of water needs to be replaced by drinking more.


Signs that a dog is on the 'net loss' side of this math and is dehydrated include:

  • Skin tenting: To check, gently pinch a fold of skin on the back of the dog's neck or shoulders. When you let go, the skin should instantly spring back into place. If the dog is dehydrated the skin is less elastic and the skin takes longer to fall back.

  • Dry mouth: Lift the dog's lip and press a finger to their gums. Dry or tacky gums are a sign of dehydration.

  • Reluctance to move: A general sign caused by the dog feeling ill

  • Sunken eyes: A serious sign of severe dehydration

  • Collapse: Seek urgent veterinary attention!

Avoiding Dehydration

Prevention is better than cure, so make sure your dog always has fresh drinking water available. But remember: elderly, stiff dogs may be too sore to get up and drink regularly, so provide them with water bowls close to their favorite snoozing spot.


Also, if your dog needs to drink a lot (perhaps they have diabetes or a kidney problem) then be sure to put lots of water bowls all around the house. Check regularly that the bowls haven't been knocked over and are topped up.


Change the water at least once a day so that it's fresh and appetizing. Some dogs find moving water more inviting to drink, in which case invest in a pet drinking fountain.


Also, some dogs dislike the taste of chlorinated water from the faucet. Try letting the water stand in a jug for 24 hours before putting it down to drink (the chlorine evaporates off) or give the dog mineral water.


In hot weather, always take a large bottle of water out on walks, and be sure to stop regularly to offer the dog a drink.

And Finally...When to Seek Help

If you suspect your dog is dehydrated but they refuse to drink or can't keep water down, then contact your vet immediately. Also, if they are losing large amounts of fluid in diarrhea or urine, then get professional help. The underlying issue needs addressing to stop the upset tummy or diagnose why they are peeing more, and intensive support with intravenous fluids may be necessary.


Don't take risks with dehydration! Remember, water is vital to life and a net loss of water can kill. If you are worried about your dog's health then always contact a vet.

Book me a walkiee?
Sketch of smiling australian shepherd