Two dogs were poisoned by what is believed to be blue-green algae at Latsch Island recently. Hershey, a chocolate lab, was comatose when she arrived at the veterinary clinic last Wednesday and narrowly survived.
Like other algae, blue-green algae are microscopic aquatic plants. However, unlike other algae, blue-green algae produce toxins that can harm humans — especially children — and kill animals, including dogs and livestock. One species of the algae produces a neurotoxin that typically kills dogs in minutes, explained Dr. Lehua Maloney of Winona Veterinary Hospital. Another species produces a liver toxin that can also be deadly, but is less potent. Hershey apparently consumed some of the liver-toxin-producing algae in a pool on Latsch Island and then began swimming in the river. Hershey lost consciousness while swimming and had to be rescued from drowning in the river. Another dog was hospitalized due to suspected blue-algae poisoning after swimming in the river, but also survived, according to Pet Medical Center.
Blue-green algae flourishes in warm, stagnant pools with lots of nutrients such as decaying leaves. Dr. Maloney said she believes the algae was probably growing in a shallow pool left behind by rain or the retreating flood waters on Latsch Island, not in the river itself. According to the Minnesota Pollution Control Agency (MPCA), water with dangerous amounts of blue-green algae will appear blue, green, or yellow. The MPCA advises humans to avoid touching or ingesting water contaminated with the algae and to keep their animals away from the water, as well. If human or pets contact the water, the MPCA recommends rinsing it off and seeking medical help if the person or animal becomes sick.
"Really watch where your dogs are going, because if your dog gets into a pool like this and take a couple sips, you can have a dead dog in minutes," Mahoney warned.
Blue-green algae poisoning cases have occurred in the area before, though Mahoney had never personally seen a case before. This year's long, wet spring may have created ideal conditions for the deadly organism, she hypothesized.