Subscribe for 99¢

(CNN) -- A doggy play date in a North Carolina pond turned tragic after three pups died from toxic algae. Now, their owners say they hope their loss will educate fellow dog lovers about the dangerous blooms.

Melissa Martin and Denise Mintz took their beloved dogs Abby, Izzy and Harpo to a pond in Wilmington on Thursday night to cool off. But within 15 minutes of leaving the pond, Abby, a West Highland white terrier, began to have a seizure.

Martin rushed her to a veterinary hospital, with Izzy and Harpo right behind her. Upon their arrival, Izzy, also a Westie, started seizing, and both terriers rapidly declined. Then Harpo, her 6-year-old "doodle" mix therapy dog, began to seize and show signs of liver failure.

By midnight Friday, all three dogs had died, she said.

The culprit, Martin's veterinarian said, was poisoning from blue-green algae present in the pond where they played.

"What started out as a fun night for them has ended in the biggest loss of our lives," Martin wrote in a Facebook post that has since been shared more than 15,000 times.

Martin said she didn't see any signs warning of toxic algae near the pond, which sits next to a popular walking trail. It's her mission now, she says, to erect signs about toxic waters and warn pet owners about the blooms.

"I will not stop until I make positive change," she said. "I will not lose my dogs for nothing."

Pets-Dispatch newsletter

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.