A 3-year-old border collie died shortly after eating water hemlock at Horsetooth Reservoir in Larimer County, Colorado, on Sunday, June 28.
Within an hour of eating the plant, which is highly toxic to humans, the dog died while being transported to Colorado State University Veterinary Teaching Hospital. “It started to go down rapidly with losing all the functions and she passed out,” Ludi Fischer, a friend of the dog’s owner, told KDVR. “She couldn’t stand up anymore. She was panting very heavily. Her eyes were out. I mean you couldn’t tell she wasn’t there.”
Hemlock is native to the area, but it’s uncommon for dogs to eat it, although it regularly kills livestock. Tim D’Amato, land stewardship manager for Larimer County, told Coloradoan that the dog’s death was “unprecedented.”
Though health officials said there’s no heightened risk to people or their pets, D’Amato said the county will probably post warnings about the plant.
“Water hemlock is one of the most lethal plants in North America,” said Dr. Dawn Duval, Department of Clinical Sciences associate professor at Colorado State University. “It’s a plant that grows in very moist areas, around ditches and lakes.
“This dog just got unlucky and kind of started playfully chewing on a plant that it shouldn’t be chewing. Water hemlock is not a plant that would be particularly appealing to dogs.”