No matter where you live, trips to a nearby lake or pond are a favorite summer pastime. If you have a water-loving dog, lakeside adventures are a great way to burn some energy and cool off.

While it may seem impossible for your dog to avoid glittering water on a warm day, it’s always a good idea to do a little inspection before either of you wade in. It's not uncommon for Minnesota lakes and ponds to produce harmful algae blooms, which put people and pets at serious risk for illness.

What’s an algae bloom?

According to Minnesota Pollution Control Agency, blue-green algae isn’t actually algae. It’s a type of bacteria — called cyanobacteria — that's found in many lakes throughout Minnesota and the country. When conditions are just right, the bacteria can grow rapidly, forming toxic "blooms." Blooms can occur anytime during the summer, but are normally associated with warm weather and low rainfall.

These blooms look like thick green paint or scum ranging in size and density and can turn the overall appearance of the lake a murky brown color. They might also produce a swampy odor. Harmful algae thrives in shallow water and can often be found on a shoreline.

Not all algae is harmful, but some species contain potent toxins that can be deadly to dogs and other animals, and it can be difficult to know the difference. There are ways to test for blue-green algae, but if you suspect your nearby watering hole might have a harmful bacterial growth, its best to keep out!

Hot and dry weather conditions can lead to blue-green algae on some Minnesota lakes. Some dog deaths have also been linked to exposure to blue-green algae in recent years. As a result, the Minneapolis Park and Recreation Board (MPRB) recommends using caution and preventing pets from drinking the lake water.

What kind of health risks are related to algae blooms?

Both humans and pets, especially dogs, can become sick soon after swallowing water containing high amounts of blue-green algae. Even breathing in airborne water droplets can cause illness. Within minutes of exposure to toxic levels of bacteria, animals can experience symptoms including vomiting, diarrhea, weakness, difficulty breathing, and seizures. In animals with weakened immune systems, high levels of toxicity can be fatal.

Always check water conditions of bodies of water, including slow-flowing streams, that your pet may have access to. Keep them away from algae-laden water entirely. If your dog does enter water with algae growth, be sure to immediately hose them off to prevent them from licking off the potentially harmful algae.