Blue-green algae warnings as temperatures rise
If a dog has been in potentially contaminated water they should be washed thoroughly.
The British Veterinary Association (BVA) and Dogs Trust have each issued warnings as temperatures rise again in the UK.
Dog owners are being urged to take care around bodies of water, as blue-green algae begins to spread in the hot weather.
Blue-green algae, or cyanobacteria, often develops in lakes, ponds and rivers. In warm and sunny weather this develops into algal blooms, which can prove dangerous for dogs, livestock and birds.
Even ingesting a small amount of blue-green algae can cause serious illnesses in dogs. It can even be fatal, due to its effect on their liver and neurological system.
Dogs may ingest the harmful bacteria by drinking contaminated water or licking it off their fur after swimming. BVA also warns that toxic blooms can drift to the edge of bodies of water.
Symptoms of poisoning can appear within minutes. This includes vomiting, diarrhoea, drooling, muscle tremors, seizures, breathing difficulties and collapse.
Owners that suspect their dog have ingested blue-green algae should contact their veterinary practice urgently. Although there is no antidote for the poison, if caught quickly, they may be able to flush the toxins from the body.
Dogs Trust is urging dog owners to keep their pets away from still or stagnant water during hot weather, looking out for warning signs around the water. BVA recommends the UKCEH’s ‘Bloomin’ Algae’ app, where users can submit details of suspected algal blooms.
If a dog has been in potentially contaminated water, they should be washed thoroughly to remove the algae. Contact your veterinary practice immediately for advice.
Rob Williams, BVA junior vice president, said: “Lots of dogs love water and won’t hesitate to dive straight in when they see a lake or go for a paddle in a pond. But toxic blue-green algae is very difficult to identify and, if ingested, can make dogs seriously ill and can even be fatal.”
Charles Matthias, senior veterinary surgeon at Dogs Trust, said: “We’re urging all dog owners to avoid letting their dogs swim in or drink from lakes or rivers that look green, scummy, have surface foam or have warning signs nearby. Blue-green algae is not always easy to spot, so if in doubt, don’t let your dogs swim in or drink from the water.
“And, if you are walking your dog near water where blue algae have formed, keep them on a lead.”
Image © Dogs Trust
The BSAVA has opened submissions for the BSAVA Clinical Research Abstracts 2026.
