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Scots warned of deadly algae in popular loch that can kill dogs and make people sick

Dog owners have been issued an urgent warning after toxic algae was found at a Scottish beauty spot.

Blue-green algae, which emit toxins that are lethal to dogs and other animals, have been seen in Loch Lomond.


Toxic algae have been spotted in Loch LomondCredit: Loch Lomond and the Trossachs National Park
Loch Lomond is a popular destination for locals, tourists and dog walkers.


Loch Lomond is a popular destination for locals, tourists and dog walkers.Credit: Alamy

National park officials have warned visitors of the deadly danger, which can cause liver failure and kill a dog in 15 minutes, that has been seen in Milarrochy Bay.

People enjoying weekend sunshine in the park have been urged to stay away from the deadly affair.

They warned visitors on social media: “Please note that we have received reports of blue-green algae in Milarrochy Bay which can produce toxins that can kill dogs and other animals.

“In humans it can cause rashes after skin contact and illness if ingested.”

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Sunlight-loving algae, called cyanobacteria, are found naturally in inland waters, estuaries, and the sea.

It can also be harmful to humans and can cause rashes if it comes into contact with the skin.

People who have swum or swallowed the algae may experience skin rashes, eye irritation, vomiting, diarrhea, fever, and muscle and joint pain.

Symptoms of blue-green algae poisoning can take anywhere from 15 minutes to a few days to develop and can include vomiting (sometimes bloody), twitching, seizures, and increased thirst.

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Those poisoned can also suffer from drooling, diarrhea and difficulty breathing.

Lake officials can’t say when the dangerous substance will disappear, depending on the weather and how warm the water is, it may only stay for hours or days.

The national park council says: “We are often asked to advise when the warning ends. However, this is difficult to predict, because blue-green algae can form in the water and dissipate again within hours or days, depending on the weather and the water’s temperature


ACCORDING to Bute & Cowal Vets, blue-green algae can’t actually be seen until they start to clump together

Once it clumps together, there are a few different ways that blue-green algae appear in the water:

• May look like a green or bluish scum in the water

• It might look like someone has thrown blue or green paint into the water

• May clump together to resemble seaweed

• May appear in brown clumps along with other weeds in the water

• May appear as green flakes or brown dots

• Can cloud water and make it appear green, blue-green, or brown-green

• You may see foam at the edge of the shoreline, which may look like sewage contamination.

Some (but not all) species of blue-green algae release dangerous toxins into the water.

There’s no way to tell if algae is toxic just by looking at it, and even blue-green algae aren’t always toxic—some types are safe while others are only toxic at certain times of the year when they’re blooming.

“Flowers normally form in calm, warm water, so they can form on a calm morning around sheltered coastal areas, but then get broken by rain or waves if the wind blows.

“Because of this changing nature of blue-green algal blooms, we recommend that people exercise caution if they know there has been a warning in the past few days.”

Last July, a dog died after being exposed to deadly algae at Loch Eck in Dunoon.

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The dog passed away shortly after showing symptoms, prompting vets to issue an urgent warning.

You should always report any blue-green algae that you have not noticed to SEPA and your local council.

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