We all know the importance of hydration and the dangers that dehydration brings for our pets. However, did you know there can be too much of a good thing? Your pet can be susceptible to hyperhydration if they consume too much water. This condition, also known as water intoxication, water toxaemia or water poisoning, is relatively rare but can cause severe symptoms and can even be fatal.
Hyperhydration is often caused by dogs swallowing too much water during swimming, diving, playing in the pool/lake or even playing with the hose water in the garden. Although it can occur, it is rare that pets will voluntarily ingest too much water to overwhelm normal kidney function and the ability to excrete excess water. Don't allow your dog to swim or retrieve in water unchecked and take frequent rest breaks.
If there is ingestion of excess water in the body this will lead to hyponatremia- extremely low levels of sodium concentration in the blood. The excess water in the blood will cause the sodiumconcentration to lower. The body will want to reach an equilibrium within the cells and the blood, causing the water to move into the cells cause the cells to swell. Organs such as the liver can sustain the increased levels of water, however the brain (which is encased) has no space to allow cells to swell which can lead to brain damage.
It will depend on the dog’s size in how likely or how much is needed to lead to water intoxication. Agility dogs, that might do training in swimming pools to improve endurance, are at risk for ingesting too much water, quickly. High energy dogs often have lower fat reserves and higher pain thresholds prompting them to push through discomfort even after they’ve taken on too much water. Smaller breed dogs are also higher at risk as they will require less water to be swallowed to risk water intoxication. It is also important to take note of your dog's swimming style. If they like to splash or hold their head low in the water especially with their mouth open, they are at greater risk for water intoxication.
The treatment for your dog will depend on the severity of the condition. In mild cases of hyponatremia, the vet will give them fluids containing sodium concentration and observe the dog for signs or neurological problems. In severe cases, the main goal is the raise the concentration of sodium in your dog’s blood, but there can be unreversible damage.