HomeVeterinaryWater poisoning in dogs – is it real?

Water poisoning in dogs – is it real?

Water poisoning… is this a thing? Well actually, yes, it is. Water intoxication is a rare condition that can happen when a dog ingests water to the point of excess. This creates some serious problems in the body and may even result in death. Let’s explore what causes water poisoning and how you can avoid it happening to your pet.

What is water poisoning?

Water poisoning, otherwise known as water intoxication or hyperhydration, occurs when a dog drinks an excessive amount of water in a short period of time. 

Usually, the sodium concentration in the blood is about the same as the cells in the body, and everything is kept in balance. But an excess of water dilutes sodium in the blood causing an issue known as hyponatremia. Usually, it is the kidneys’ job to maintain water and sodium levels, but in this scenario, they don’t have time to sort things out. The dog is taking on more fluid than the kidneys have chance to eliminate, resulting in blood that becomes watery (dilute).

Dangerously low levels of sodium mean that water starts to flow from the blood into the cells, as the body tries to correct the hyponatremia. This extra fluid results in swelling of the cells. Organs like the liver can withstand a bit of swelling, but more sensitive organs like the brain (which is encased in bone) cannot. Brain swelling, or cerebral oedema, gives rise to multiple symptoms which we will explore later on.

How does water poisoning occur?

In people, water poisoning most commonly occurs during water-drinking competitions or extreme exercise regimes. Water poisoning in dogs is more likely to occur in those that spend a lot of time swimming, as well as playing in and around water. 

Dogs that dive repeatedly or that play fetch in the water, are more likely to swallow large amounts of fluid. Dogs that play-bite streams of water from hoses or sprinklers can end up ingesting more than usual too. 

High-energy and high-drive dogs are more likely to keep playing these sorts of games to excess. 

This may come as a surprise to many owners, who involve water in their play to keep their dogs cool and well-hydrated during the summer months. But just as dehydration can cause problems in our pets, so can overhydration. It is important to strike the right balance.

What are the symptoms of water poisoning in dogs?

Symptoms may include –

  • Lethargy
  • A bloated abdomen
  • Vomiting
  • Wobbliness or loss of coordination
  • Drooling
  • Pale gums
  • Glazed eyes
  • Enlarged pupils
  • Collapse
  • Breathing difficulties
  • Seizures
  • Death

If you think your dog is showing symptoms of water intoxication, then contact your vet immediately.

How is water poisoning treated in dogs?

Your vet will start by examining your dog, checking their heart rate, breathing effort and body temperature. 

They may suggest a blood panel next. This will be to check your pet’s electrolyte levels (including sodium) but they may also need to check your pet’s haematology (white and red blood cells) and biochemistry (liver, kidneys, blood sugar and protein levels). This will give them an idea as to the overall health of your pet and help to rule out other issues.

If water poisoning is suspected, then your dog may require hospitalisation and treatment. Levels of sodium will need to be increased in your pet’s blood, but this must be administered with care as too much sodium could also cause neurological problems. Vets may need to administer diuretics to help speed along the rate at which fluid is eliminated and also medication to reduce pressure in your dog’s brain.  

Mild cases can return to normal with the right care, but more severe cases may suffer from permanent damage. Sadly, euthanasia may be advised for some patients. 

How can I avoid water poisoning?

It is not usually necessary to stop water-play altogether. Instead, owners should supervise their dogs closely and try to limit excessive amounts of water games. 

Make sure that your dog has regular rest breaks from swimming, with plenty of opportunities to go to the toilet. Dogs that splash around a lot in the water or carry their head low, are more likely to swallow water while swimming than other dogs. So, make sure that you keep an even closer eye on how long these pets are spending in the water.

If you are playing fetch in the water, use an object that your dog finds easy to bite and closes their mouth properly on, like a flat frisbee. You should also not encourage them to bite at high-pressure water jets like hoses, as this could result in them swallowing large amounts of water in a short space of time. 

Never restrict your dog’s usual drinking water however, this should always be freely available.


Water poisoning is rare but can be extremely serious if your dog is affected. However, there are sensible steps that you can take to keep your dog healthy and happy this summer. These include frequent rests from water play and stopping them from biting at jets of water. 

Keeping cool and well hydrated in warm weather is still vitally important, but just remember that everything is best when kept in moderation, even water.

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