Dog dies after swimming in toxic Bay Area lake

CASTRO VALLEY, Calif. (KGO) -- Dog owners are being warned to be careful after at least one dog, and maybe more, died from swimming in a toxic lake. The conditions at Lake Chabot may have been brought on by the drought.

It's suspected that the slimy blue-green algae in the lake caused the death of a dog that played with Karen Johanson's dog. They share the same veterinarian. Johanson said the dog that died was "the sweetest chocolate lab, Josie. Just a wonderful dear gentle soul."

"In the 80 year history of the park district, this is the first year we've had a toxic algae blooms," Carolyn Jones, an East Bay Regional Parks spokesperson, said.

Signs have been placed around Lake Chabot warning people and their pets not to come in contact with the water. It's believed the drought created ripe conditions for this algae bloom.

"I've been living in Castro Valley since '99 and it's just the lowest level I've seen it," John Mammino of Castro Valley said.

The low water level and warm winter temperatures likely created the brackish water conditions. The symptoms in dogs that consume the toxic algae are: vomiting, diarrhea and seizures that can lead to difficulty breathing, liver failure and death. Human deaths are not common, but it can make people very sick.

"We do ask that people, if you're fishing in Lake Chabot, to clean your fish thoroughly and throw away the fish guts," Jones said.

Pets were never allowed in Lake Chabot because it's a backup water supply, but now pet owners have good reason to keep them out.