The MPCA recently received a report of a suspected dog death as a result of exposure to blue-green algae. Although the Department of Health has not confirmed the cause of death, if you are a dog owner, it better to be safe than sorry. Be sure to check water conditions when your dog is playing near lakes or slow-flowing streams.
Blue-green algae “blooms” have a thick, cloudy appearance that can look like green paint, pea soup, or floating mats of scum. Some, but not all, species of blue-green algae contain potent toxins that can be deadly to dogs, livestock, and other animals within hours of contact.
If possible, keep your pets away from algae-laden water entirely. If your dog does go into water with heavy algae growth, hose it off right away, before it has a chance to lick itself clean. Animals become ill when they ingest the toxins, so preventing them from drinking affected water or licking toxins from their coat is key to preventing illness.
If you are concerned that your pet has been exposed to harmful blue-green algae, take the animal to a veterinarian immediately.
What causes blue-green algae?
Blue-green algae blooms can occur anytime during the summer, though they are normally associated with warm weather and low rainfall. Algae are a natural part of the ecosystem, but under certain conditions, algae populations can “bloom” with dramatic growth. Most blue-green algae are not toxic, but there is no way to visually identify whether a particular bloom contains toxins that are harmful to people or animals.
Algal blooms develop when lakes contain excessive levels of nutrients such as phosphorus. The best way to prevent them over the long term is to reduce the amount of nutrients that run off into lakes from fertilizers and organic materials like leaves and yard waste. Once a bloom has developed, there is no way to correct it. Blooms often come and go quickly, so the best option is to stay away from the water until rainfall, wind shifts, or cooler temperatures disrupt the algae’s growth.
The best way to prevent algal blooms over the long term is to reduce the amount of nutrients that run off into lakes from fertilizers and organic materials like leaves and yard waste. Once a bloom has developed, there is no way to correct it. Blooms often come and go quickly, so the best option is to stay away from the water until rainfall, wind shifts, or cooler temperatures disrupt the algae’s growth.
Human deaths from exposure to blue-green algae are extremely rare, since the unpleasant odor and appearance of a blue-green algal bloom tend to keep people out of the water. If people do come into contact with toxic blue-green algae, they can experience skin irritation, nausea, and eye, nose, and throat irritation. People should never swim in water if they suspect a blue-green algae bloom.
For more information
Find out more on MPCA's webpage about blue-green algae blooms.