i clip my yorkies nails and have never had a problem.
i have to do zacs as he wont let a vet do it anyway, he bites and backflips off the table when the vet tried to do it, so the vet could only do his back ones as there was no way zac was going to let him near the front ones, well not without drawing blood and i dont mean zacs lol
but if i do it hes fine he just lays there on my lap on his back with his legs up in the air lol