DOG OWNERS are being warned to stop their pets swimming in water containing potentially fatal blue-green algae. 

Various vet groups warn that dogs can develop poisoning from the algae when they drink it from water, or lick themselves after swimming in it.

This in turn has a toxic effect on the stomach and internal organs, which can be fatal.

The algae is usually found in ponds and lakes, and has started to flourish due to the recent hot weather.

Symptoms of poisoning include generalised weakness and lethargy, diarrhoea, laboured breathing and muscle tremors.