Authorities in west-central Minnesota say one dog died and another became seriously ill after apparently being exposed to toxic blue-green algae while swimming in an area lake.
The Douglas County sheriff’s office said the Thursday reports led them to consult with the Minnesota Department of Natural Resources.
A DNR conservation officer said the conditions at Red Rock Lake appeared to be consistent with an early bloom of blue-green algae.
The sheriff’s office said property owners and others using Red Rock Lake are strongly encouraged to prevent animals and children from going into the water.
Warmer temperatures coupled with excess nutrients being washed into the water can cause the harmful algae blooms. Pets, livestock and humans can be at risk.
While not all blue-green algae are toxic, the Minnesota Pollution Control Agency says harmful blooms often look like pea soup, green paint or floating mats of scum, and they often have a bad odor.
Such conditions were observed on Red Rock Lake, the sheriff’s office said.
The shallow, 900-acre lake is located in southwest Douglas County, near Kensington.
Swimming in water with an algae bloom can cause a skin rash, hives, runny nose, irritated eyes and throat irritation. Swallowing the water can cause vomiting, diarrhea or nausea; headache, throat irritation or muscle pain are also possible.
Dogs are at particular risk from wading in shoreline areas, where algae accumulates, and they can suffer seizures and convulsions from exposure to toxic algae.
The MPCA says that once blue-green algae blooms occur, the only option is to wait for the weather to change — rainfall, wind shifts or cooler temperatures — to disrupt the algae’s growth.
Until then, the agency advises limiting animal and human exposure to questionable waters. If your dog does go into waters with heavy algae growth, hose it off right away before it has a chance to lick itself clean. If you’re still concerned about exposure, consult your veterinarian.