Mirkka Koivusalo from the Toronto Centre for Canine Education http://thetcce.com demonstrates how to train your dog to allow you to grab his collar. This is an action you probably will have to do eventually and many dogs dislike it, therefore it is important to train your dog to tolerate it.
Stage 1– Make a motion towards your dogs collar from different angles without actually touching it, and reward your dog.
Stage 2– Lightly touch your dog’s collar from different angles, rewarding each time.
Stage 3– Lightly insert one finder underneath your dog’s collar from different angles, rewarding each time.
Stage 4– Lightly grasp your dog’s collar only when he/she exhibits comfort with earlier stages, rewarding each time.
It is important to take small steps ensuring your dog is comfortable with each stage before moving on to the next. Crouching, yawning, licking lips or looking away may be signs that your dog is getting stressed. Revert back to the previous step if your dog exhibits this behaviour.