Pet owners in the South Bay are encouraged to be extra vigilant.
Authorities said white powder was found placed along Three Creeks Trail in the Willow Glen neighborhood between Willow Street and Bird Avenue.
Someone is believed to have left a small amount of cat food laced with the white powder on the trail, which is popular with dog owners.
A dog owner said her 4-year-old black labrador retriever gobbled up a couple of bites of the cat food Tuesday morning.
The owner became concerned and took her dog, Oreo, to a nearby pet hospital as a precaution.
"The dog was induced to vomit and it all came up and the dog is going to be OK," San Jose Animal Control Capt. Jay Terrado said.
Police sent the case to animal control on Wednesday after the dog's owner reported their pet got sick
Terrado said the substance will be sent out for testing on Thursday to a laboratory at UC Davis' school of veterinary medicine. Results are expected to return in two to three weeks.