Dog owners are being warned to keep their pets on leads around lakes and rivers due to a toxic algae that can be potentially fatal to animals.

The British Veterinary Association (BVA) has issued its annual warning to owners, asking them to take extra precautions when walking dogs due to an increased risk of toxic blue-green algae.

In late April, a cocker spaniel died of suspected blue green algae poisoning after a swim in Anton Lakes, Hampshire.

More locally, incidents of blue green algae blooms have closed off the water at Llyn Clywedog near Llanidloes and Llangors Lake near Brecon, both in Powys - although both have subsequently reopened. The Clywedog incident saw the lake closed for watersports, although fisheries on the lake remained open.

Blue green algae, or cyanobacteria, are a group of bacteria that can contain dangerous toxins which can be harmful and potentially fatal to pets, livestock and birds if ingested even in small quantities.

County Times:

Dogs can swallow it by drinking water from an affected lake, river or pond or while licking their fur after going for a swim.

It’s possible for dogs to come into contact with the bacteria even if they don’t go into the water for a paddle, as toxic blooms are often blown to the edges of water bodies.

According to trend data supplied by Professor Alan Radford and his team at SAVSNET, University of Liverpool, suspected or confirmed cases reported by veterinary practices peak in July and August, at the height of the summer season, and aren’t restricted to any one part of the UK.

BVA President Justine Shotton said: “Many dogs love nothing more than a paddle in a lake to cool off in this weather, but we’d urge pet owners to keep them on a lead during walks near water bodies confirmed to have algal blooms this summer.

“The majority of blooms are toxic and it is impossible to tell the difference visually, so it is better to be safe than sorry.

“It is also important to be aware of the symptoms of exposure.

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

“They can appear within a few minutes or hours of exposure, depending on the type of toxin ingested, and can cause liver damage and ultimately be rapidly fatal if left untreated.

“There is currently no known antidote for the toxins, so dog owners should seek prompt veterinary treatment to tackle their effects and ensure a good chance of recovery for their pet."

Top tips for pet owners

  • Look out for any warning signs put up by the responsible national environment agency or local authority near water bodies.
  • Keep pets on a lead and by your side around water bodies known or suspected to have a blue-green algal bloom – don’t let pets swim in it or drink from it.
  • If your dog has been swimming outside, wash its coat thoroughly with clean water afterwards.
  • Seek emergency veterinary treatment if you’re concerned your pet may have ingested toxic algae.
  • Report sightings of suspected blue-green algae with a photograph via the Bloomin’ Algae app. You can also set up notifications for confirmed sightings in your area.