Dog nail grinders are also known as dremels. They are a type of nail grooming device used to trim a dog’s nails. They are electrically powered, some come with electric cords, while others are wire-less as they feature rechargeable batteries to maximize portability.rnrnNail grinders are easy to use and less stressful for your dog. They work by using a rotating part that is generally covered in a material similar to sandpaper. This material helps in wearing down the dog’s nails in a quick manner.