DENVER (KDVR) — A Colorado woman says her dog is finally home after being poisoned by seeds from a popular ornamental tree in a city park.

Megan Hanson said her 6-year-old golden retriever Murphy spent nearly a week in Wheat Ridge Animal Hospital undergoing treatment.

“It was just the hardest week of my entire life,” Hanson told NewsNation affiliate KDVR, recounting what happened after Murphy ate some brown seeds he found in Denver’s Washington Park.

That tree, KDVR found, is more common than you may think.

‘I noticed he was pretty lethargic’

Hanson noticed a change in Murphy’s behavior after a trip to Washington Park on April 21.

“He’s always sniffing the ground and chomping on sticks and leaves, and then later that night, I noticed he was pretty lethargic,” she said.

Hanson rushed Murphy to the emergency clinic after his symptoms got worse.

“There’s definitely a point where we thought he wouldn’t make it,” she said.

Veterinarian Stacy Meola found a pod and seeds in Murphy’s system and quickly identified them as coming from a Kentucky coffeetree.

The Colorado State University College of Veterinary Medicine guide to poisonous plants confirms toxins are present in Kentucky coffeetree leaves and seeds. It is also associated with the poisoning of livestock that consume water tainted with the seeds.

KDVR asked Denver Parks and Recreation about the number of trees in nature areas. A spokesperson told KDVR that Kentucky coffeetree seeds can be toxic to pets, and there are more than 3,100 planted throughout the system — some of which are believed to be 80-100 years old.

Kentucky coffeetrees can largely survive anywhere in the continental U.S. — except coastal parts of California, northern Minnesota, and southern portions of Texas and Florida — the Kentucky coffeetree is most commonly found in the Midwest and parts of the South.

According to the U.S. Department of Agriculture, Kentucky coffeetrees are often used in parks or for large area landscaping. While early settlers were known to use the beans as a substitute for coffee, the agency notes that the seeds and pods are poisonous.

However, researchers haven’t determined what exactly makes the seeds and pods poisonous, the University of Minnesota explains.

How to tell if your dog ingested a toxic substance

“There are seed pods, there’s toxic mushrooms and other plants out there, so you really want to be keeping an eye on them that they’re not eating anything,” Meola said. There can be other risks, however. “I’ve had dogs that have found illicit drugs and other foreign bodies. There’s some crazy things out there.”

The key sign of exposure to a toxic substance is continuous vomiting.

“Vomiting once is typically not a concern. They start to become lethargic, their appetite goes down, you start to see other signs — that’s when you should get them in and they should be evaluated,” Meola said.

Hanson said Murphy is recovering but will take time to regain his strength. She’s just happy to have her best friend home again.

“We go hiking, we love to go camping together, he loves to go skiing. He’s like the perfect Colorado dog,” she said.

Veterinarians told KDVR that pet owners should always keep their emergency number nearby and bring their pet in for medical attention if they experience excessive vomiting, diarrhea, dizziness, tiredness, seizures or changes in eating habits.