Getting Your Dog To Tolerate Nail Trimming
Even if you won't be doing the trimming yourself, it's a good idea to help your dog get comfortable being handled this way. Most dogs are fearful of getting their nails trimmed because it feels unnatural. The fear becomes worse if they have been nicked by the clippers before. They just don't want their feet touched anymore. As with most training, teaching your dog to tolerate (even enjoy) a trim is a simple process. The time it takes depends only on your persistence and reliability.
Building Trust & Holding Hands (or Paws!)
It's important to be able to handle your dog's feet without him feeling the need to struggle or get away. This is not only helpful for grooming, but also inspecting your dog for injuries or transporting him to a vet when an injury occurs. And teaching your dog to trust you with his sensitive toes will build upon other areas of trust.
Take a moment to think about what your dog's most urgent desire is when you try to touch his feet. You can easily come up with his reward for this first exercise. He wants to get his foot away from you! That's understandable. But what you will demonstrate to him is that nothing bad will happen when he lets you hold it, and he can get you to let go by holding still for long enough.
Take your dog's paw into your hand and simply hold onto it. (Do not do this if your dog has a history of biting at you, please consult a professional dog trainer in person so he can observe what is going on and offer appropriate advice. Fear aggression is a delicate issue.) As you hold his paw, he will likely pull away. Simply hold on and don't let go. Don't squeeze so hard as to hurt him, but don't give into his struggle.
The moment he stops squirming, give a reward signal for correct behavior. Say "yes!" in your most excited-happy voice and release him. If you delay too long he will begin to struggle again and you may reward the wrong behavior. Timing is everything.
Repeating this simple process a handful of times each day will soon have your dog convinced that if he holds still long enough, you'll just let go. You can gradually increase the amount of time you hold onto his paw before letting go as you learn what he is willing to tolerate.
Treats Definitely Help
Even though this exercise can be done completely without treats, you may need additional motivation for a stubborn or more anxious dog. The approach is slightly different.
While sitting on the floor and holding your dog's paw, have a bag of treats behind you and one in your other fist. Holding it in your fist allows him to smell it and know that it's available, but doesn't give him access to it yet. Remember you only want him to have the treat at the time you signal correct behavior. For the moment it only acts as a distraction to prevent too much anxiety and struggling. You can lure him into holding still by letting him smell it in your hand, but because you are a responsible and fair leader, you'll only give it to him when he's done what's required of him.
Types of Trimmers
Nail trimmers come in different styles, each having a usefulness in different situations. Scissor and guillotine types can be scary for a dog because they squeeze the quick a little even during a correctly done trim. This doesn't hurt your dog, but does cause anxiety. Some dog owners who home-groom use grinders for this reason, with the biggest hurdle being the noise instead of any physical discomfort. Discuss options and proper cutting with your vet or groomer before attempting a home-trim on your dog.
My personal preference is a scissor style trimmer. I have a very large Doberman Pinscher. It takes a long time to grind his nails, and they are large enough I don't feel confident using guillotine trimmers. Heavy duty nail scissors allow me to trim the sides of each of his nails alternately until they are the right length. Moving from side to side prevents squeezing the quick under his nail so he doesn't become fearful, and makes it easier to cut through his rock hard nails. It takes a little longer so I reward his patience with treats and only do two paws before taking a break.
Most dogs forget that you have hold of their paw when they smell a delicious enough treat. Use that moment of stillness to your advantage. Signal he's done right when he sits still and let him have the treat, but don't let go of his paw. Keep holding on and saying "yes!" and feeding more treats so long as he holds still. You can let go and tell him "all done" after half a minute of this.
Holding his paw will soon mean a wealth of delicious treats. To decrease his dependence on food rewards, gradually increase the time between multiple treats with each exercise. He'll have to hold still for longer between them. Eventually change it up to only one treat at the very end of the exercise, then only verbal praise sometimes and treats occasionally.
Moving On & Making Progress
Whatever trimmers you've decided on, your dog needs to get comfortable around them. Depending on his level of anxiety, you may need to think small. You'll learn your dog's behavior threshold for the trimmers when he again starts to struggle. So far, you've got him sitting still for little feet massages or hand holding. But add a trimmer to your other hand and it may all seem forgotten.
Take it easy. If he starts struggling at the mere sight of the trimmers, wait for him to hold still again, say "yes!" and set them down. Seeing them doesn't mean you're about to manhandle him into submission. You're still rewarding the right behavior with something he desires. He holds still and you set the trimmers aside. You can continue holding his paw, or let go with your signal, it's up to you and how large of a reward your dog needs.
Wait a moment or two and try again. Move the trimmers towards him, if he struggles, freeze in place. Wait for him to hold still with the trimmers at his threshold distance and then signal and put them back down. You will see his threshold decrease with practice. It may be right away, or it might take a few lessons like this.
Keep up this practiced routine until you can touch your dog with his trimmers, and eventually make a few cuts. In the beginning, shorter lessons are better. Super short lessons are much more effective than trying to force your dog into learning by spending more time at it. You will both get frustrated and that will increase his dislike for a nail trim.
Always try to end on something you know your dog will succeed with, and give a clear signal that his work is finished by telling him "all done" and showing him your palms before getting up. Letting him know the lesson is over for the time being by using a release cue immediately frees his mind to relax.
Staying Focused On Success
That's all there is to it. Take everything in small steps. No matter what you're trying to teach your dog, you should always be mindful of ways you can help him succeed. Leave him little room for mistakes and you'll see progress faster. Look for ways to prevent things that throw a wrench into your training sessions. For example, if your goal is to simply hold onto your dog's paw, but you can't keep him in the same room with you, use a tether during training. Or shut the both of you in the bathroom so he has to use sitting still rather than running as a solution. Practiced often enough, he won't view fleeing as a necessary option and lessons can be done with more freedom. Stay solution focused and try not to see problems as unavoidable. There is always a work-around.