Water – ABCs of poisons

Have you ever paid attention to your dog’s swimming technique? Watch your dog the next time they are swimming; do they jump or dive into the water, cause lots of splashing with their doggy paddle, hold their head too low in the water, swim with their mouth open or cough when they come out of the water? If so, their swimming style might make them more prone to water intoxication.
Excessive voluntary water consumption is usually an indicator of an underlying medical condition and should be assessed by a veterinarian. However, there are circumstances where water is ingested unnecessarily and this can lead to water intoxication. Examples include dogs that have been swimming, especially if retrieving objects in the water, diving or chasing waves, and those that enjoy playing in a stream of water from a hose or sprinkler. Swimming in rough water may also increase water ingestion.
Excess fresh water consumption lowers the sodium concentration of the blood; a condition called hyponatraemia. This leads to movement of the water into cells throughout the body. Most organs can cope ok with this swelling, but the brain cannot expand very much since it is encased in the bone of the skull. If brain swelling is severe or prolonged, irreversible brain damage may result.
Excess salt water consumption increases the sodium concentration in the blood; a condition called hypernatraemia. This leads to movement of water from inside cells into the blood, causing the cells to shrink. When this happens in the brain, the brain cells can separate from their myelin coating leading to reduced transmission of electrical signals. This results in permanent brain damage.
Early signs of water intoxication from either fresh or salt water ingestion include lethargy, vomiting, diarrhoea and/or bloating. Signs of brain dysfunction include weakness, confusion, loss of coordination, muscle tremors, seizures and coma. Water intoxication is a true medical emergency and veterinary treatment must be sought immediately to prevent permanent brain damage. Careful treatment with diuretics or low sodium fluids along with regular blood sodium monitoring is necessary to ensure brain function is preserved.
If your dog has a susceptible swimming style avoid throwing objects for them to retrieve or use a flat object to allow them to better hold their mouth closed. Consider the use of a dog life jacket/floatation device to keep them higher in the water.
If visiting the beach, even for a short period, always carry ample fresh water and a travel bowl with you. Offer your pooch a drink every 15 minutes; this will make them less likely to drink sea water and if they do, the fresh water should help to balance out the salt consumed.
The Animal Poisons Helpline is free to all pet owners in Australia and New Zealand. If you are concerned your pet may have been exposed to a poison, phone 1300 869 738 (AU) or 0800 869 738 (NZ) for advice, even if your pet looks well.
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