Our beloved black lab is 12 this year and not doing well. She is happy and pain free thanks to the drug metacam. Two winters ago she tore her tendon in her back leg. Of course favoring it her other one went out. Her walking is OK, just slow are careful. She gets in and out and only stays on the first floor now. The problem is that the past few months she is having a harder time. She has slipped and fallen a couple of times on the kitchen tile. She is also having neurological twitching. The vet said it might get worse or it will stay the same. Today I got home and she could barely walk, her front legs were very stiff. I am so sad. This is our first baby. If she continues to worsen we will put her down. I am so worried that something will happen when we are on vacation in February. My DH said he will put her down before our vacation if she is looking bad. He would rather she have us with her when it is time and not the pet sitter. I think he is right. Though I am beginning to think the end may be closer since her issues are getting worse. She is just so happy all the time. That makes it worse in a way because you always doubt yourself unless it is obviously time. 
I just went through this with my going on 14 yo dog. Putting area rugs everywhere helped with slipping and mobility issues - odd is it seemed having a rug in the kitchen it really helped. And then with walking, in the last week when legs were stiff a rolled up towel in front of the hind legs really gave him extra support and seemed to keep him comfortable.
