An improved trimmer is structured to be held in the palm of a user's hand. The trimmer has a grinding drum that is advantageously structured to be situated in a palmar region of the user's hand that can be said to extend from the palm and to be generally bounded by the fingertips. When the trimmer is held in the palmar region, the thumb and certain fingers can support the trimmer, and other fingers that are not necessarily employed in supporting the trimmer are usable to operate a control switch of the trimmer. The control switch controls operation of a drive motor that is connected with a grinding drum which provides abrasive surfaces that are engageable with the animal nail or claw.