A number of gruesome discoveries involving mutilated animals have prompted a southwestern Ontario humane society to warn pet owners about a possible serial animal killer on the loose.

Last week, police in London, Ont., responded to a report of a headless dog found on top of a recycling bin near a beer store. The animal had been skinned and was missing organs.

It was the latest in a series of similar disturbing incidents in which dead animals were found in public places around the city, according to the London Humane Society’s executive director Judy Foster.

Over the last year, Foster said, there have been at least eight incidents involving 17 dead animals, including a skinned and beheaded bunny found on the Western University campus, a mutilated cat found in a park, six dead coyotes — two of them headless and skinned — placed in a pose in three different locations, and seven dead snakes left in a strange pose.

A stabbed and partially skinned goose was dropped off at the humane society’s front door, she said.

“It doesn’t make me feel better knowing there is such great similarities between all of these and the disturbing part is you don’t know when the animals died — at the start, halfway through or as a result of what was done to it,” Foster said. “It’s impossible to forget what we’ve seen.

All the animals were found with some form of mutilation, but there was no blood at the scenes, Foster said, suggesting they were killed elsewhere.

A scalpel appears to have been used in each case, she said.

“The animals are incredibly clean,” Foster said. “We believe that it would take a fair amount of time to do that.”

It also looks like the pattern is escalating, she said. First it was wildlife — coyotes and geese — and then a bunny, a cat and now a dog.

Foster said she doesn’t know if it’s the work of one person, a group or even copycats.

But Michael Arntfield, a criminology professor at Western University, believes one person is behind all the incidents.

“This will continue to escalate,” he said in a phone interview. “This is not a prank, it’s not mischief, it’s sexual, it’s predatory, it’s high risk and it’s criminal.”

Arntfield, a former police officer, is confident that one of the incidents — the mutilated goose that was dropped off at the humane society — suggests the person has been to the humane society before.

Two years ago, Arntfield said he received a tip that someone was going to the London Humane Society claiming to be a rescuer and asking to adopt animals “with the sole purpose of torturing them and mutilating them.”

Arntfield told police and the humane society and urged them to examine the adoption files. Nothing happened, he said.

“This is a serial animal killer,” Arntfield said, calling it a clear case of zoosadism — being sadistic to an animal — with an underlying sexual component.

Arntfield said he is concerned that whoever is behind the animal killings could potentially move on to more serious crimes targeting humans.

The incidents have left the humane society reeling.

“We’re doing OK, but I’m not going to downplay it,” Foster said with a heavy sigh. “I felt physically ill when I saw the dog, and the bunny, the cat, the goose, the coyotes...the skinned coyotes we thought were dogs initially.”

She said counsellors are coming in soon to help staff deal with the gruesome discoveries.

“The longer we talk about this, the hair on my arms are standing straighter and straighter,” Foster said. “It’s chilling. And at a certain point, when these things keep happening, we also need to be concerned about public safety — public human safety.”

London police said they are taking the matter very seriously.

Const. Sandasha Bough said the force has assigned an investigator to the case, but noted they were only made aware of two incidents — two dead coyotes found by a grocery store last February and the beheaded dog last week.