I just saw a post on the USN website (suspets) that a blue algae is in some lakes and can kill a dog that has been swimming in a body of water that has it. Death is within hours.
They say that the algae is sometime not visible.

Eric,
People that did not like dogs,just loved Luvvy….hence the name.

She was my constant companion in field & stream,not a trained hunting dog by any means but I would just watch her body language and she would spot game long before I could.

Wayne