DOG-OWNERS have been warned not to let their pets swim or drink from Pickmere Lake due to toxic algae levels.

Chris Moseley, Marbury Park ranger, received a call from Helen Hammersley earlier this month when her dog became ill after walking near Pickmere Lake.

Chris suspected the cause may have been blue-green algae, which can form during bouts of hot weather.

“They suggested I placed signs saying there might be blue-green algae in the water, so that’s what I did," Chris told the Guardian.

Blue-green algae produces toxins that can kill animals and can also be harmful to humans.

“You would need to drink quite a lot of it for it to kill you, but what it can do is cause quite a nasty skin rash,” Chris said.

Warning signs have been placed around Marbury Park since the end of June.

Chris said there have been several reports of dogs falling ill in Marbury Park.

Helen’s dog, Charlie, had been out walking by Pickmere Lake with her daughter and her dog, Russell.

Later that night Charlie became ill.

“When they got back he stood up and couldn’t walk,” Helen, from Barnton said.

“I just thought he was hot and tired. He didn’t change so later on I text my daughter to see how Russell was and she said he wasn’t well too.”

Helen tried for hours to cool Charlie down, thinking he may be suffering from heat exhaustion.

“He started having seizures. He was in a really bad way. I was terrified. He’s fit as a flea, he’s a really healthy, happy dog.

“I thought, he’s not going to be alive if I don’t do something.”

Helen met up with her vet around 2am, who confirmed he had ingested something toxic and put Charlie on a drip.

Charlie, who is a two-year-old rescue dog, received various treatment over the days that followed, and has managed to make a full recovery.

“He came to me at a time in my life, well he rescued me. He means everything to me,” Helen said.

“I am pretty sure that if I hadn’t have got to the vets when I did he wouldn’t be alive now.”

A spokesman for Environment Agency confirmed they tested Pickmere Lake earlier this week and found toxic levels of blue-green algae.

Chris said: “Blue-green algae won’t disappear now until there is severe frost. Looking at the situation it could be until Christmas."

He advised dog owners to not allow their pets to swim or drink from the lake for the foreseeable future.