Sarah,
Not sure what I can add really except please read those threads that paws and Angela have provided links to.
To be clear, there are only TWO TYPES of head-halter/collar, regardless of brand:
MUZZLE-CLAMPING TYPE ~ the tightening action of these head-halters CAUSES THE DOG PAIN, although the manufacturers will describe it as 'pressure', however, dogs will move into pressure (opposition reflex) so if this were the case, they wouldn't be effective in stopping the dog from pulling. By tightening around the muzzle they cause the dog pain at various points on its head ~ THIS IS WHY DOGS HATE THEM ~ and if used on an aggressive dog it can even make the aggression worse. Muzzle-clamping head-halters include the brands Halti, Gentle Leader (which is far from gentle), GenCon and Canny Collar.
FIXED-ACTION TYPE ~ these head-halters have no moving parts, which means that they don't tighten around the dog's muzzle and head and DO NOT cause pain - they very simply give better control because the dog is being led by its head. This type of head-halter is the ONLY type that, if one of my clients really needs to use one, I am prepared to recommend. Brands include PAH own brand and Dogmatic. The Dogmatic is very well-designed and doesn't ride up under the dog's eyes - the makers actually designed the halter for their own Dobermans. Dobermans and other long necked breeds often suffer irreparable cervical spine (neck bones) damage from the use of muzzle-clamping head-halters, which just goes to show how much better, safer and kinder the fixed-action Dogmatic is compared to the muzzle-clamping types.
Lizi, Tilly & Beau
