Southern Ontario dog owners are being warned to keep a closer eye on their pets after a rash of scares involving poison and marijuana left out in the open for their pets to eat.

Amy Jackson, a veterinarian at a Barrie, Ont. clinic, said she has witnessed a recent spike in the number of dogs ingesting toxins while out for a walk or playing at off-leash dog parks.

“We are finding that most of them are positive for THC. We have also had some that have tested positive for opiates as well,” she told CTV Southern Ontario on Wednesday.

Chris Veinotte brought his dog Bandit to Barrie’s Sunnydale Dog Area on Sunday evening. A few hours later, Bandit collapsed and started to vomit.

“He was peeing himself, shaking like crazy. If you put your hand anywhere near him he would jerk away,” he said. “You could tell he was terrified. He was looking at you, but kind of looking through you.”

Veniotte lifted the husky-shepherd mix into his car and rushed him to a local emergency veterinary clinic.

“I thought my dog had a stroke or suffered a seizure,” he said. “It was terrifying to see a pet you love, part of the family, collapse on the floor and not be able to move.”

Veinoitte, who volunteers with an animal rescue group, hoped the marijuana that made his dog sick was accidentally left behind by a careless pot smoker. But when he posted about what happened online, several other local dog owners told him they had the same experience at the same dog park.

Tara Martel and her husband visit the Sunnydale Dog Area every day with their dog Wilbur. Martel said she noticed her dog was staggering after a recent morning walk.

She initially thought he hurt his hind legs or his back, but became alarmed when he started dribbling urine. She too rushed her dog to the nearest clinic.

“We did a urine test and were able to identify that he had gotten into marijuana at the dog park,” she said. “It's a little frustrating because you think, ‘I’m going to an off-leash dog park . . . that it should be a safe place for my dog to be.’”

Jackson said it is critical for owners to bring their pets to a clinic as soon as they notice symptoms like difficulty walking, uncontrolled urination, dilated pupils, slower than normal heart beat, drowsiness, and sensitivity to loud noises.

She said marijuana can be particularly difficult to treat if owners do not witness the dog consuming it. The symptoms often emerge after it is too late to induce vomiting.

“We usually look at giving them some activated charcoal, which is a liquid which may help to bind anything that is left in their stomach. If they are quite severe, we will put them on IV fluids and keep them in hospital overnight.”

Dead critters and poisoned food

Nearly 200 kilometers away near Brantford, Ont., Susan Havens is worried that somebody is trying to kill her dog Fiona.

She says she pulled a suspicious piece of sausage or pepperoni from Fiona’s mouth on Monday. Upon closer inspection, she noticed the meat had been hollowed out and filled with what she believes was a “large piece of rat poison.”

“I was shocked that anybody would dislike the dog that much or dislike me that much that they would do something like that,” she said. “I was extremely, extremely angry that somebody would go to these lengths.”

Luckily, Havens got to Fiona before she was able to swallow the tainted meat.

Havens lives on a quiet street in the community of Boston, where she said many people have dogs. She’s worried that whoever left the meat in her yard may have done the same to her neighbours.

“I have been finding dead animals, and I have also been finding random food on my property,” Havens said. “The police don’t think this is a one-off. They think this has happened before.”

Ontario Provincial Police Cst. Ed Sanchuck confirms the meat contained some type of poison.

“We are going to investigate this to determine how this got on her property, where it came from and why it got there in the first place,” he said. “We have someone that is putting people in danger.”

With reports from CTV’s Brandon Rowe and Alexandra Pinto