Swimming in or drinking from water with a blue-green algae bloom

Hazard

Cyanobacteria blooms in stagnant lakes, ponds, and rivers can produce microcystin and anatoxin, which can cause liver failure or neurologic collapse within hours. Dogs can also be poisoned by licking algae off their fur after swimming. There is no antidote.

Notes

Blooms often appear as bluish-green scum or foam on the water's surface, especially in hot weather.

Source: Cornell University College of Veterinary Medicine; AAHA · view original