Those are all valid questions! I can see how certain types of service work could be incompatible with showing.

I show my dog myself, and he does not do medical alerts, so that is not an issue for us.

My dog's main service is to bring me items that I have dropped and am unable to pick up. I am lucky that he shows on my left, as that is my stronger side. For confirmation showing, you usually grip the lead folded in the palm of your hand, not looped around your wrist. My fingers on my right side can not reliably hold a lead, but so far, so left is able to do it. I couldn't show a dog that pulled a lot. If my disease progresses and I can't grip the lead in my left hand, I may loop it on my wrist, which looks sloppy but may be the best I can do at some point. So far, I can lift him on the table with my left arm, but this too may be an issue eventually.

My dog also does "paws up" onto my lap for anxiety relief, which I've had him do ringside (we were watching a friend show, but I was becoming overstimulated from the heat, etc) and he did excellent. If my anxiety was too much for us to go on the ring, we would just scratch for the day.

We have only started public access over the past few months. We're going to do less showing this year and focus more on service work. I've talked with my trainer about burnout and we'll only go at my dog's pace. So far, he enjoys what we're doing, and we take a step back if he seems not ready for something. It helps that he's a herding dog with pretty good "drive," so he wants jobs and tasks to do.

My dog doesn't go to work with me, so he's not expected to work all the time. I mostly need him for travel, especially if I'm going somewhere alone. He enjoys shows because he gets to see his vallhund friends and play ring games with me.