Human beings are not dogs. Or cats. You seem to have missed out on thousands of years or evolution, societal practices, beliefs, and concepts such as the spirit and the soul. We recognize that dogs are not human, and they are not afforded the same rights as humans. This argument is a total non-starter, imo. Well, at least until Planet of the Apes becomes a thing. Then we're going to really think about state sanctioned suicide for them too.
I disagree.
I think the argument that we would not let pets suffer at end of life is very relevant when trying to justify why we make people suffer
Dogs do not have the same rights in that the owner has to choose for them - people ca n choose for themselves.
At least they can where this is available.