The meat is suspected to be tainted with rat poison, and a sample has been sent to a Washington State University lab for testing.
Owners Kyle and Allyson Barker had taken Berdy, their golden retriever, on a hike around 10 a.m., and noticed Berdy was eating something off the ground as they hiked the same path back to the parking lot.
Kyle pulled meat out of the dog's mouth, and thought nothing more of it until a couple approached the family with photos they had taken that morning.
The photos had been taken in two separate locations along the trail, and show similar suspicious looking chunks of meat.
"We were terrified. We were concerned the poison might act quickly and we had a matter of minutes to get her to throw up," Kyle Barker said.
The Barker's believe whoever left the poisoned meat was likely walking the trail the same time they were. Berdy would have surely gobbled the meat the first time she passed it, they say, as it was when they passed the same spot on their way back that she found the chunk.
Vomiting was induced at the clinic after vets found green pellets in her stomach. After emergency care by vets, the Barkers say Berdy is doing better.
"It's just kind of sick. I don't know who would dislike dogs so much that they'd do something like this," Kyle said.
Berdy had no immediate signs of being ill, but veterinarian Dr. Jeb Mortimer said depending on the kind of poison and amount ingested, pets can exhibit symptoms within 12 hours, a few days, or weeks.
"I think this intent is malicious," Dr. Mortimer said. "Someone's trying to kill dogs in my opinion."
The Barkers plan to notify the Seattle parks department, and aim to warn other pet owners in hopes to catch the culprit.