It's hard to explain. You know how some people pop their knuckles, backs, knees, necks, wrists, etc.? Well lately there are times where I kinda hear my dog's back pop. For example, my dad was trying to pull my dog up closer to him in the chair, and we heard my dog's back pop. Is this ok? Should we take him to the vet? He's supposed to go for his yearly check up in May, so should I bring it up then?