Knee pain and dog walks

I took Shaemus the dog in my car to a park.  He rides well in the car and we had a lovely walk.  I think it tired him out and he may not drive me nuts at night.  Just when I am ready for bed, he thinks it is play time.  I feel guilty not taking the  dog for a walk, so there is another reason to fix my knee...it is not getting better...exercise helps temporarily but the pain and swelling is still there.    Between my Mom and my sister, I think I am headed for a knee replacement.