Dog owners are being warned to be wary around lakes and rivers due to potentially fatal toxic algae.

Blue-green algae, a group of bacteria called cyanobacteria, often resembles foam and can be found at the edges of lakes and rivers.

It can be hard to see blue-green algae unless it has collected together, therefore it can pose a risk to dogs.

The PDSA warns: "The opportunity to splash around can be hard for any pet to resist but don’t forget to be cautious of blue-green algae in early autumn.

The Argus: "More prominent in warmer weather, blue-green algae is highly toxic to pets and can quickly become fatal, so if you see a blue-green layer on any body of water, avoid it entirely.

"Muddy, stagnant puddles or ponds can also give your pet a stomach upset, so it’s best to avoid these too."

When you do see large patches of blue green algae, it’s common to see green flakes, brown dots and greenish bundles.

There could be dead fish in ponds and lakes that have a high concentration of toxic bacteria, and you should not let your dog drink from water containing deceased animals.

Why is blue-green algae dangerous?

Patches of blue-green algae contain extremely harmful toxins which stop a dogs liver from functioning correctly.

Although not every type of blue-green algae is dangerous, it’s important to be cautious when walking near bodies of water to prevent your dog from becoming unwell.

Exposure to blue-green algae is often fatal, and for dogs that do survive they can be left with long lasting health problems.

Some types of blue-green algae can have fatal effects quickly and can kill a dog in as little as 15 minutes to an hour after drinking contaminated waters.

Symptoms of blue-green algae poisoning

If your dog has been swimming or paddling in water and they start to show any of the following signs, contact your vet immediately and tell them you are concerned about blue-green algae:

  • Seizures/fitting
  • Vomiting
  • Diarrhoea
  • Difficulty breathing
  • Weakness
  • Collapsing
  • Unconsciousness
  • Confused or disoriented
  • Dribbling

If caught early enough, your vet will attempt to make your dog vomit in an attempt to flush the toxins out of the body. There is no antidote, but if medical intervention occurs early this gives your dog the best chance at surviving.

Sadly, blue-green algae poisoning often eventually causes fatal liver failure, so it is important owners are vigilant.

How to protect your dog from blue-green algae

  • Keep your dog away from bodies of water that you suspect to contain blue-green algae.
  • Do not allow your dog to swim or paddle in waters that contain blue-green algae
  • Don’t let your dog drink water that could contain blue-green algae. Wind often blows blue-green algae to the edges of ponds and lakes and higher concentrations of toxin can reside here, where your dog is more likely to drink.
  • Note warning signs and hazard notices during dog walks and follow the advice provided.