Blue-green algae grows quickly in water bodies with high nutrient levels such as phosphorus or nitrogen. The agency blooms are appearing in lakes and ponds in southern Wisconsin and will gradually show up in the northern reaches of the state as the summer continues.
DNR officials say people who touch the algae or accidentally ingest water containing it can become sick. Pets that come into contact with it by drinking algae-contaminated water or licking algae from their coats can die. The DNR says if dog owners that notice their pets are lethargic, suffering from vomiting, diarrhea or seizures should contact a veterinarian.