A warning has been issued by a dog owner whose pet was left gravely ill after taking a drink of water from a river.

Vets didn’t think Tyson would pull through after he ingested what is thought to have been algae from the River Fillan, near Crianlarich, as he cooled off during a walk.

The Collie-Hungarian Vizsla cross collapsed not long after and had to be rushed to an emergency vet.

His owner Karen McLareny was told the beloved 12-year-old might not make it but thankfully he defied the odds to recover.

Karen is now urging other dog owners to be aware of the dangers over fears another pet might not be so lucky.

Algae is extremely harmful to dogs. It can cause skin rashes, sickness, stomach pains, fever and headaches in humans. There have been some reports of more serious illnesses including liver and brain damage.

Karen had taken Tyson on a leisurely walk along the banks of the river on Friday with her other dogs, Archie and Floyd.

Karen said: “They were all in the river swimming and Tyson wasn’t feeling too well and he trotted down to the riverbank and had a mouthful of water.

“Later on he was sick and couldn’t get up.”

Tyson and his pal Floyd

Worried Karen rushed him to the emergency vet in Falkirk who kept him in for treatment and observation. He was placed on a drip and and had a fever of 104.

Karen added: “It was really worrying. The vet said ‘I don’t think he’s going to make it’. We had to go home and leave him there and the vet would phone us in the night if anything changed.”

Karen was relieved not to receive a phone call in the night and by Monday Tyson was transferred to his own vet, Riverside Veterinary Clinic, in Callander, before being allowed to return home to continue his recovery.

Karen added: “He’s doing a lot better.

“The vet was amazed that he has recovered so well.

“I hope that if we can highlight this and if it stop just one dog from becoming sick then great.”

A mysterious substance in the River Fillan near Crianlarich

Karen has been left with a £1,000 vet bill but says that it’s a price worth paying to nurse Tyson back to full strength.

Following the incident, Karen reported the potential poisoning to the Scottish Environmental Protection Agency (SEPA), which acts as Scotland’s environmental watchdog who investigate algae accumulation. A spokesperson this week said: “SEPA was notified by a member of the public on Tuesday 1 June of their dog becoming ill after entering the River Fillan in Crianlarich on Friday, May 28.

“We notified Scottish Water who attended the location and confirmed their infrastructure in the area was working as it should. SEPA is carrying out investigations to determine the source.

“If you see any signs of algae or potential pollution, we ask that they contact our 24-hour pollution reporting line as soon as possible. This can be done through our online form at www.sepa.org.uk/report.”

Pet owners should refrain from allowing their dogs drinking or even swimming in water containing blue-green algae.

Blue-green algae can look like green flakes, greenish bundles or brown dots in a pond, lake or stream and is most common during the hotter, drier summer months when there is less rain.

When the algae blooms, it can look like a blue-green scum has appeared on the surface of the water and has been reported to look similar to pea soup.

When the bacteria that forms the algae clumps together it produces harmful toxins which stop a dog’s liver from functioning properly.

Exposure to toxic blue-green algae is often fatal.

Pets may show any of a host of symptoms, including; vomiting, diarrhoea, seizures, unconsciousness, confusion, drooling and breathing difficulties.