Police in Canada are investigating after a woman was caught swinging a puppy on a leash as a weapon.

An insane dash cam video captured by a motorist in Dartmouth, Halifax showed a female motorist taking the dog from its owner before beating her over the head with her own pet.

The incident occurred on July 1, when police responded to reports of an altercation between four women.

“The altercation started after two females in one vehicle confronted two females in the second vehicle regarding being cut off in a drive-thru,” Halifax police said.

One video circulating on social media shows the moment the argument breaks out; the two vehicles are stopped with their wings right against each other, as one driver roars in through the window at the other, before the two begin exchanging blows.

But the second video, filmed by a motorist waiting behind, shows one of the drivers grabbing the other’s puppy by its leash, and dragging it by the neck towards her car.

When the owner pursues her to try get the pet back, the first driver swings the tiny dog by its leash like a nunchuck, smashing the terrified animal into the side of its owner’s head.

Screaming frantically, the owner tries to grab the poor pooch back, while the first driver continues to swing it by its neck, finally whipping the owner with the other end of the leash when she eventually lets go, before walking away.

Neither of the women wanted to press assault charges when police arrived; however following outcry after the circulation of the video on social media, investigators took things into their own hands.

“There were initial reports of a dog being involved but the extent was not clear at the time. Officers checked on two dogs in one vehicle and they appeared to be in good health,” Halifax Police explained in their statement on Saturday. “The severity of actions against the dog were not known at the time.”

Officers said they had become aware of the video, and said they are now investigating it as animal cruelty.