MADISON – The estimated 50,000 or more Wisconsin waterfowl hunters whose favorite hunting partner has four legs, a tail and doesn’t mind swimming in cold water may want to take some precautions against their friend coming down with serious illness from ingesting water containing potentially toxic blue-green algae. “The waterfowl hunting practice of hunter and dog working together is part of a long and rich tradition for many waterfowl hunters,” said Kent VanHorn, DNR migratory waterfowl biologist. “Sometimes, care of these furry hunting companions requires extra awareness and practices. While not widespread (three Wisconsin dog deaths from blue-green algae poisoning were reported in 2008), a new concern in the care of waterfowl hunting dogs is potential toxicity from blue green algae.” With about 85,000 waterfowl hunters, Wisconsin has the second highest number of waterfowl hunters in the country. Texas, a much larger state, is number one. About 60 percent of Wisconsin waterfowl hunters use dogs to retrieve their harvested ducks and geese. Blue green algae is present in lakes, marshes, ponds and ditches across Wisconsin but lives unrecognized except for when “bloom” conditions develop and the algae move to the water surface. When blooms occur the blue green algae can cause unpleasant “pea soup” water conditions and release toxins that can create illness and even death in dogs and humans. While blooms of this species occur most frequently in summer, blooms have been observed in Wisconsin in fall and winter. During the fall waterfowl hunting season, toxic bloom conditions can develop on warm fall days or on lakes that are in fall turn over. Hunters should be on the lookout for the following conditions in field: Blue green algae “bloom densities” can develop in surface waters with high concentrations of nutrients, particularly phosphorus Blooms are most often green or blue-green in color, but may also be blue, reddish brown, or brown. They can float to the surface forming foamy scum layers, mats or blobs. Blooms tend to grow when there is a lot of sunlight, the temperature is warm, the water is shallow and there is little wind. Sometimes when the wind kicks up, blue-green algae will pile up on the windward side of the lake. Bill Delanis, DVM, DNR wildlife veterinarian suggest hunters follow the following advice of the Wisconsin Veterinary Medical Association to help protect their dog’s health: Provide a good supply of clean fresh water for your dog to drink while hunting. Wash your dog thoroughly after being exposed to unclean water. Toxins can be absorbed through the skin as well as ingested. Dogs could be affected by blue green algae toxins ingested while cleaning themselves, so watch for this activity. Do not allow your dog to swim in bodies of water where there is a visible bloom occurring. After potential exposure, watch your dog for signs of lethargy, loss of appetite, diarrhea or more severe symptoms like seizures, vomiting, and convulsions. If your animal show any of these symptoms you should seek veterinary care. More information on blue green algae in Wisconsin FOR MORE INFORMATION CONTACT: Bill Delanis, DVM, DNR wildlife veterinarian (608) 266-3143 or Kent VanHorn, DNR migratory waterfowl biologist (608) 266-8841.