Taking care of your dog with things like clipping toenails, putting in ear drops, or taking his temperature can be fraught with anxiety, for both the dog and you. Use co-operative husbandry to make it easier on both of you.
So what exactly is cooperative husbandry? Well, cooperation between the dog and you comes down to trust, which can be crushed in an instant, or built on to create a bond where the dog knows you won't hurt him, but he can withstand some discomfort and come through it just fine.
If you teach him what to expect, and don't spring any surprises on him while at the vets, for instance, this trust will build and become stronger over time.
Teach him that a hand coming towards him means treats, not pain or something awful.
Even if it is awful, he can take it and not get reactive or resentful.
The first thing to do is put a leash on your dog - this is not to punish him, or correct him, but simply to keep him close to you. If you've been using positive reinforcement for a while to train him, he'll probably already know that near you is where the rewards are.
The first step is to reach out and touch him on the shoulder, as most dogs don't see this as threatening or aversive. A simple touch, then a treat. Do this several times, then change to the other hand. Then touch his neck, repeat, with a treat after every touch.
This process will need to be split into several sessions, so don't think you need to rush through it. Slow soft, gentle training, in tiny increments, is much better for them to understand.
After they are not jumping away, twitching or trying to evade your touch, you can move to touching their ears, then their legs and feet. The back, belly and tail are sometimes where the process falls apart, but just step back a bit, and return to the place where they were comfortable before moving on.
Humans are so impatient!
Then you will need to move to a new area in your house, and repeat the whole thing again, so he knows to generalize between the living room, the kitchen, the bathroom, out on the deck, in the front yard, in the back yard, on the driveway and so on.
Get some implements (these don't have to be the exact things a vet will use, but find something different, that he doesn't see every day). Do the whole thing again, using the implements instead of your hand.
Press on both sides of his body, put one hand under his tail and one under his chest. Then pick him up, very briefly, put him down immediately.
Eventually, you will be able to look inside his ears, check his eyes, gums, teeth, lift his tail, press on his belly, pick up each foot individually and poke into each toe, and then it's time for the vet to do her thing, and use the same process, slowly introducing implements like the stethoscope, toenail clippers, the thermometer and the othoscope.
Co-operation between your dog and someone caring for him is a whole lot easier if he's done some practicing; your vet, groomer and dog walker will be extremely grateful.