My aunt gave me one of these because her dogs did not like it at all. And my dogs hate this thing. They don't like the sound and they hate the feeling even more. It's more of a fuss trying to use this on them than actually cutting their nails (which they're great for anyway, being groomed once a month since puppies), and it didn't bring down the nail at all. Trying to get a dog with really long nails filed right down would take forever, if they didn't mind the feeling of it. If anything I would use it to file their nails down after having cut them so they're not sharp.