Been watching other groomers work on dogs lately and i've noticed that they tend to clip nails even though the nails are already quite short. They aren't touching the ground and aren't causing the dog discomfort in any way yet they still clip them. I've seen a couple of dogs who had nails that were as i described above and they had their quick's cut because the groomer thought the nail needed clipping but because the nail was black they didn't realise how close the quick was.
I have done this myself as well, the owner wanted the dogs nails trimmed. The dog had black nails and i took just the very tip off the nails as they were already quite short, this resulted in the quick being cut. I know the more you clip them the shorter the quick goes, but i still find it a little odd that people see the need to clip them SO short even though the nails are not harming the dog in any way.
I don't need to clip my dogs nails at all (even the dew claws, they use their dew claws enough to keep them worn down) because they just wear them down themselves, however if i sent them to a groomer, they would probably clip them a bit, just for the sake of it, which i really don't understand. Of course with the correct method, clipping nails is very safe, however accidents happen and I tend to think why should we risk it unless the dog genuinely needs his nails clipped?