One dog has died and another is ill from suspected blue algae poisoning after they swam in a Minnesota lake.
According to the Douglas County Sheriff's Office, its water patrol team was alerted to the two pets falling ill after entering Red Rock Lake, near Hoffman.
One of the dogs has since died, with officials saying the symptoms are consistent with blue algae poisoning.
The sheriff's office spoke with the Department of Natural Resources, which said that heavy rainfall runoff and recent warm and humid temperatures have caused an "early bloom" of blue algae on the lake, with visible areas of floating mold on parts of it.
"Property owners and other persons using Red Rock Lake are strongly encouraged to take any measures to prevent animals and children from having any exposure with, inhalation, or ingesting water suspected of being contaminated with blue algae," the sheriff's office said in a news alert.
"Property owners are also asked to talk with seasonal residents and visitors to Red Rock Lake about the conditions," it added.
Blue algae exposure symptoms in humans include stomach cramps, diarrhea, vomiting, headache, fever, muscle weakness and difficulty breathing. Those experiencing them should call their doctor or the Poison Information Hotline on 800-222-122.
Pet owners should call their veterinarian if their pet is displaying seizures, vomiting or diarrhea after contact with surface water.
The Minnesota Pollution Control Agency says blue green algae is often said to resemble pea soup or green paint, but that it can take other forms as well. You can find out more here.