18 Jul 2025
Senior clinicians have pleaded for caution following the recent heatwaves, which it is feared could have enabled the toxic, and potentially fatal, bacteria, to grow in waterways across the UK.
Allister Webb
Job Title
Image: Andre Engelhardt / Adobe Stock
Veterinary and welfare groups have urged pet owners to be cautious about walking their dogs near rivers, ponds and lakes due to the threat posed by blue-green algae.
Although storm warnings are in place across much of England for today and tomorrow, the BVA has warned the recent hot weather raises the risk of cyanobacteria growth.
Recent sightings have been reported in Greater Manchester and the Lake District, as well as parts of Wales, Scotland and Northern Ireland.
BVA junior vice-president Rob Williams said owners should keep their dogs away from waters where the toxin is known to be present or if they are unsure.
He added: “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.
“With no known antidote for the toxins, prompt treatment is critical to help give affected pets a chance of recovery.
“Symptoms can appear within a few minutes or hours of exposure, and commonly include vomiting, diarrhoea, drooling, disorientation, trouble breathing, seizures and blood in faeces.
“If you have any concerns or are worried your pet may have had contact with blue-green algae, speak to your vet as soon as you can.”
The UK Centre for Ecology and Hydrology does offer a Bloomin’ Algae app which allows the public to report sightings of the bacteria.
But clinicians acknowledge the bacteria can be difficult to see and Dogs Trust senior vet Charlie Matthias echoed the cautious message.
He 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.”
