Dogs aren't OP. It's just that everyone is using them because it the default assault streak. The dog is pretty bad. It only gets between 1-2 kills and it gets killed.
ANd if you think it's so OP then why don't you use it yourself? Quit the whining.
SNipers are just fine. They kill like they should and they get hitmarkers when they should. You are just used to bo2 sniping which was extremely easy. Sniping is just fine. And if you think it's that bad then why do you continue to use the sniper rifles? If something isn't working for you then why would you keep using it. Seems like common sense