There is a serious and deadly warning out to pet owners this summer if you plan on hitting lakes.
Blue-green algae has taken the lives of several dogs over the past few weeks in North Carolina, Texas and Georgia according to CNN.
And that same algae has been found in Lake Needwood and nearby Lake Frank north of Rockville, Maryland.
Three dogs in North Carolina died within hours of exposure to a toxin from a blue-green algae bloom in a local pond.
The owners reported that after one dog started acting strangely, the other dogs soon started seizing and showing signs of liver failure.
All three died just after midnight Friday.
Blue-green algae is most common in the summer. It is capable of producing harmful toxins to humans, pets and fish.
The Virginia Department of Health says samples collected at the end of July show harmful levels in several areas in Virginia, including near Lake Anna.
CLICK HERE for a guide to the map above that shows where algae blooms have been confirmed.
According to Blue Cross for Pets, a UK animal charity, there's no cure for the poisoning, and exposure nearly always leads to death in dogs. Drinking from a body of water where blue-green algae lurks or licking it off fur can kill a dog within 15 minutes of exposure.
According to the Department of Natural Resources, some Maryland waters also have a few spots with harmful algae.
To check the map, click here.
The Centers for Disease Control and Prevention says the "cyanobacteria blooms can look like foam, scum, or mats, particularly when the wind blows them toward a shoreline. The blooms can be blue, bright green, brown, or red. Blooms sometimes look like paint floating on the water’s surface. As cyanobacteria in a bloom die, the water may smell bad, similar to rotting plants."