A mash potato-like substance which can kill a dog in as little as 15 minutes has been found in a Norfolk broad.

Dog owners are being warned of the dangers surrounding blue-green algae after it was confirmed in Barton Broad, near Neatishead.

Blue-green algae is a term which describes a group of bacteria called cyanobacteria.

The sample was taken by The UK Centre for Ecology and Hydrology on September 5. 

It can be hard to see blue-green algae unless it has collected together, where it can often resemble foam and can be found at the edge of lakes or ponds.

North Norfolk News: Stock image of blue-green algaeStock image of blue-green algae (Image: PA)

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Exposure to blue-green algae is often fatal and can kill a dog in as little as 15 minutes to an hour after drinking contaminated water.

Wind often blows blue-green algae to the edges of ponds and lakes and higher concentrations of toxin can gather here, where your dog is more likely to drink.

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Dogs who survive can be left with long-lasting health problems as harmful toxins can stop a dog's liver from functioning correctly.

Symptoms can consist of seizures or fitting, vomiting, diarrhoea, difficulty breathing, weakness, collapsing, unconsciousness, confusion or disorientation, and dribbling.

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