VISITORS to a Herefordshire beauty spot are being told to avoid the water after blue-green algae was confirmed at the nature reserve.
Herefordshire Wildlife Trust has put signs up at Bodenham Lake, between Hereford and Leominster, to warn visitors.
The risk to human health is considered very low, but algal toxins in the water can cause rashes after skin contact and illnesses if swallowed.
Visitors should avoid entering the water to swim or paddle and prevent their pets from entering the water or drinking from it.
What is blue-green algae?
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.
The algae may appear as green or greenish-brown scum on the surface of water. Dogs can swallow it by drinking water from an affected lake, river or pond or while licking their fur after going for a swim.
PDSA vet Anna Ewers Clark said: "Blue green algae is a bacteria can be found in slow flowing or stagnant water, such as ponds, streams and lakes, especially in warm weather.
It can be very dangerous to dogs as it produces invisible toxins that can cause organ damage and sometimes even death.
"Unfortunately it can be difficult to spot so it's important check any water for signs of blue green algae before you let your dog drink or swim, even if you've been there before.
If you're not sure if water contains blue green algae, stay away and keep your dog on the lead to keep them safe."
What are the symptoms?
Symptoms of exposure can appear within a few minutes or hours, depending on the type of toxin ingested, and commonly include vomiting, diarrhoea, drooling, disorientation, trouble breathing, seizures, and blood in faeces.
If left untreated, it can cause liver damage and ultimately be rapidly fatal.
Algal blooms have so far this year been reported in water bodies across the UK, including several locations in the Central Belt of Scotland, as well as in Derbyshire, the Midlands, Essex, Pembrokeshire and the Brecon Beacons.
British Veterinary Association senior vice president Daniella Dos Santos said: "It's been a warm start to the summer and we have started hearing of increasing numbers of blue-green algae sightings across the UK.
"While a paddle in a cool lake may be your dog's favourite outdoor activity at this time of the year, we'd urge pet owners to keep them on a lead during walks near water bodies confirmed to have algal blooms.
"The majority of blooms are toxic and it is impossible to tell the difference visually, so it is better to be safe than sorry.
"There is currently no known antidote for the toxins, so prompt veterinary treatment is the only way to tackle their effects and ensure a good chance of recovery for your pet.
"If you suspect your dog has been exposed to blue-green algae, please seek emergency veterinary treatment as soon as possible."
What is the advice?
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 blue-green algae with a photograph on the UK Centre for Ecology & Hydrology's (UKCEH) Bloomin' Algae app.
Professor Laurence Carvalho of the UK Centre for Ecology & Hydrology said: "The public can play a crucial role in providing a rapid, early warning to pet owners about outbreaks of blue-green algae.
"If people report sightings via the Bloomin' Algae app with a photograph, we can quickly check if it is blue-green algae or something harmless, with correct and incorrect reports plotted on an interactive map in the app.
"App users can also set up notifications for confirmed blooms in their area."
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