A VET is warning pet owners to look out for symptoms of a deadly dog poison caused by ingesting blue green algae.

Rob Reid, of White Cross Vets in Coulby Newham, Middlesbrough, warned there had been a 'significant increase' in cases of blue-green algae poisoning, which could be due to the spells of warm and wet weather.

He said: "These cases are usually extremely rare, so it's a big concern, as it can be deadly if not treated."

The algae blooms can appear as green or greenish-brown scum on the surface of water and can contain toxins which are harmful to dogs.

Even a small amount from a contaminated lake, river or pond can have a severe impact if a dog swallows it or even licks their fur after a swim.

Mr Reid added: "It’s nasty and difficult to diagnose with 100 per cent certainty – the only way to do that is with a post mortem - but the symptoms include everything from vomiting and diarrhoea, to drooling, disorientation, breathing trouble, seizures, blood in faeces, tremors, dizziness and a lack of muscle use. These can start to appear almost immediately, or develop over a few hours, depending on the type of toxin ingested. If left untreated, it can result in neurological problems, liver issues and death.”

Signs warning about the dangers of blue green algae are becoming more common and can be seen in several local parks and popular walking spots.

Mr Reid said the best advice was to keeep dogs out of the water and on leads during walks near water and to be vigilant.

"We would encourage owners to act fast if they suspect their dog has swallowed any contaminated water," he said.

“Although vomiting helps get rid of the toxins from their stomach, we would also treat the dog with IV fluids to flush through toxins and give them an activated charcoal feed to bind any toxins left in the intestines.

“Fast treatment normally results in a full recovery, so we want to make sure dog owners know about the dangers and symptoms of this toxic algae.”