Warning after algae which can kill dogs and harm people spotted in river

And pet owners have been advised to keep their dogs out of the river too - as the toxic algae can be fatal to animals.

Officers at Norwich City Council said they had been made aware of the potential presence of blue-green algae between the Old Lakenham Mill area and Thorpe Mill at Saxlingham Thorpe.

They tweeted: “Keep out of the water and don’t let your dogs go in or drink from that point on the river.

The council said it was working with the Environment Agency to keep the public safe.

In hot dry weather there is an increased risk of blue-green algal blooms occurring in rivers, streams and lakes.

Scums can form during calm weather which can look like paint, mousse or small clumps.

It can produce toxins which can kill wild animals, livestock and pets as well as harm people, producing rashes after skin contact and illnesses if swallowed.

Dogs can swallow the algae by drinking water from affected areas or when licking their fur after swimming in it.

The symptoms of poisoning can appear within minutes or take a few hours depending on how much has been ingested.

These include; vomiting, diarrhoea, drooling, disorientation, trouble breathing, seizures and blood in faeces.

Public health advice says people who believe they have come into contact with the algae should shower with fresh water immediately and seek medical attention if they become ill.

Algal blooms also use up vital oxygen in the water.

There are often blooms of blue-green algae in the region. Last year, there were reports at Whitlngham Broad, Blickling Hall lake and Kensington Gardens in Lowestoft.