Having almost succeeded at commiting suicide, I can honestly say there are a LOT of things going on inside the mind of a seriously suicidal person, things that are extremely hard to communicate to other people. Most of the time, people close to a suicidal person get confused and frustrated as they just can't understand what is inside their mind.

Maybe the dogs death was just a trigger to a bigger problem, maybe it WAS the problem who knows? Unfortuneatly no one will know Suicide is sad, and painful for EVERYONE no matter what the reason behind it is.