where to go from here

I have been having lots of thoughts swirling in my head lately about miller and about showing. Miller is 11 now and even though he is still running like a young dog, I am trying to decide what is fair for him and what is not. I have stopped running him in competition class and just practice small sequences in the open practice, but I am not sure if that is helping him or hurting him. I have been running/walking with him a mile or two every couple of days to keep my cardio different and to get him out. He seems to absolutely love anytime he gets alone with me so he seems happy when we run/walk so I continue to do that with him and then I give him an anti-inflammatory just in case after wards. I am of two minds here and not sure what to do. On one hand, I feel like not doing full courses could be hurting us at shows, thus the knocked bars so maybe putting him back in competition class where we run three of four full courses would be better, but then I risk doing too much with him. On the other hand, I do feel like he doesn't need the repetition and length of full courses but I need it! I get rusty too! I am not sure the running/walking is all that good for him since we are on a concrete track but that really is my only option and of course when I say running, I mean he is trotting beside me jogging. I just don't know what to do! He detests water and we really don't have any place to swim our dogs anyway so that is not an option. I have seen too many agility dogs quickly age when they cut back on what they do and i have noticed he doesn't seem as happy with life right now, partially because of all of the attention Deuce gets but partially because he isn't training as much. I know we aren't suppose to put feelings on our dogs but I can tell when he is sulky for sure as he just goes and lays in the dining room floor and ignores us. It is VERY obvious. Anyway, trying to figure out what to do. No point in trialing if we aren't going to train but I am not ready to stop trialing. We are going to take the summer off due to Tony's work situation and due to us having a little too much fun with our credit card, but want to be back showing by the September show. I am going to go ahead and do the USDAA show next weekend so I have some glimmer of hope that we might find a partner and get to go to nationals. Still thinking and ruminating about ideas and possibilities. Trying to do what is best for my best canine friend, keep him happy and let him do what he loves but still stay injury free.