London dog owners have been warned of toxic algae building up in waterways during the heatwave after a dog became ill in South London. 

It comes after Royal Parks Police said a dog had been swimming in water at Busy Park in Richmond and became unwell. 

The police confirmed that the pet had been taken to a local vet who believed a build-up in algae due to the hot weather caused the dog to be ill. 

The aquatic weed is set to be a common sight for London's waterways this summer as record temperatures hit the region. 

Richmond and Twickenham Times: Dog owners are being urged to take caution. (Canva)Dog owners are being urged to take caution. (Canva)

Dog owners have been warned of toxic algae

Blue Cross animal welfare charity shared that the blue-green algae can create harmful toxins that stop a dogs liver from functioning properly. 

As the charity told the Evening Standard: "Exposure to toxic blue-green algae is often fatal, and can also cause long term health problems in dogs that survive after drinking or swimming in algae-contaminated water.

“Call your vet immediately if you suspect poisoning. Some types of blue-green algae can kill a dog just 15 minutes to an hour after drinking contaminated water.

"Dogs who have been swimming in water can get the algae caught in their fur, and can ingest it while cleaning themselves later on."

The most common symptoms of algae consumption in dogs include vomiting, diarrhoea, seizures, fitting, unconsciousness, confusion, drooling and breathing difficulties.