The invention relates to a hook for a pet leash, intended to couple the leash to a collar or harness, with a closing system that prevents an opening or gate from being opened by a force perpendicular to the axis of same, and including a safety screw system that prevents any movement or twisting of the fastenings of the collar or harness from opening the opening of the hook, the closing position of the hook ensuring a perfect fit between pieces and making it impossible to manipulate the hook by moving it once same has been screwed. The hook is formed by pieces that require little physical effort to undo the screw and open the hook, and has a minimum resistance to pulling forces greater than 150 kg before breaking, so that the hook is reliable when used with large animals.
