Simple and classic flat buckle collars work for tags and everyday walks.
Martingale collars gently tighten to prevent escapes but avoid choking.
Head halter collars steer dogs without pressure on the trachea when training leash manners.
Controversial but effective for strong pullers, pinch collars cue leash pressure corrections.
Slip chain leashes alone act as collars for training, walking, identification tags.
Remote electronic collars deliver vibrations or shocks to reinforce training at a distance.
High-tech GPS collars track lost dogs' locations and monitor their fitness and safety.