Today our dog Bruno who is 9 years old has not been himself. He is quiet, walks slowly, has trouble getting up and the one step from the kitchen to the hallway and would not jump on my bed like he normally does. Dad felt Bruno's back legs and he started whining. Dad thinks he might have a pulled muscle. I think he either has luxuating patella, hip dysplasia or arthritus. He was fine yesterday. What could be wrong with Bruno? What should we do?