Dog suicide is unthinkable. I'm guessing there must be another logical reason for this behavior. Maybe feeling of suicide aren't just limited to humans. We see whales that purposely beach themselves ... so, maybe there is so much we don't understand about our canine friends. :frowning:
My first guess is to check out the bridge itself for any stray electrical currents on the deck. It's entirely possible the dogs are being shocked, making them jump without realizing they're jumping off the bridge itself.
Research now indicates that whales beach themselves only on certain types of beaches, where their detection system is unable to properly detect the decrease in water depth.
At least this is something I read in Australia during a whale beaching.
I also think they should look for some other mechanism than dog suicide. Maybe there is some kind of subsonic vibration that the animals can sense but humans can't.
Although dogs and cats are somewhat more emotionally sensitive than other animals because of their long close ties with humans, they would still possess the natural survival instinct that most animals have. Sick or dying animals might do things to hasten their end (starvation, etc) but that is mainly because of instincts to protect the pack/herd. I would think that humans are the only healthy animals who would take their own lives.
I definitely would look for something that disorients the animals. Many people think that whale and dolphin beachings are not willful but due to some type of disorientation. Humans are probably uniquely oblique to our surroundings and thus less disorientated than other animals by changes to our environment.