OAKVILLE, Ont. - The condition of a four-month-old Labrador retriever is improving after it ingested a white powder scattered over a trail in Oakville, Ont., Halton regional police said Tuesday.

The dog was out for a walk with its owner on the Nipigon Trail on Tuesday afternoon when it found the powder, ate it, and then later fell ill. The pup was rushed to the vet by its owner and is recovering.

Sgt. Brian Carr said officers have found what appeared to be the same powder in several other locations, including the River Oaks Recreation Centre, Taylor Woods Park and Milbank Park.

Tuesday's incident comes just a week after three dogs were sickened by tainted cupcakes left in a park in Port Perry, north of Oshawa. It's still not known what substance was used in the cupcakes.

While the cases are alarming, they're not uncommon for this time of year, said Kristin Williams, a spokeswoman for the Ontario Society for the Prevention of Cruelty to Animals.

"We hear of similar occurrences across the province every spring," Williams said. "It isn't new and we need to be vigilant."

As far as keeping pets safe, Williams said owners must have heightened awareness of the area they're in if they take their dogs off-leash. She also said dogs must be well-trained to come when they're called and to stay relatively close.

Police are urging anyone with any information on the white powder to contact them.

The OSPCA has never successfully prosecuted anyone in a similar case of dog poisoning, Williams said.

"Under the Criminal Code, it's actually really difficult to prove intent," she said. "These particular cases are very difficult to prosecute and they're heavily reliant on witness testimony."