There is an Algae outbreak in Lake Chabot which has killed 3 dogs, 1 dog died at Clear lake last year, and Lake Temescal was closed to the public for an outbreak last year.  In all the research I did about trail safety with dogs, Algae was never mentioned yet so many trails intersect with lakes, this is the first I ever heard that it was a toxic killer to dogs.  I frequent lake Anza because it is off the Wild Gorge Trail, and think that we will be staying out of all Northern California lakes to be extra safe.

http://wn.ktvu.com/story/27990715/owners-outraged-after-lake-algae-poisons-dogs-at-lake-chabot