Tera's a lovely Oldenburg mare, 12 years young and full of typical female 'tude. I give her a good hack from time to time when her college-age owner is back home for the holidays or enjoying a week of spring break. And each time I grab her bridle off its designated tack room peg, it's equipped with a different bit: a three-ring elevator, a loose-ring Waterford, something else I've never seen before ... Needless to say, she's sometimes a bit "tough" in the mouth.

Tera is the first horse I've ridden who really took to a German hackamore.

Photo: Alexandra Beckstett

Last week, however, I was surprised to find no bit at all. In her normal bridle's stead was a German (or mechanical) hackamore. At first I thought it must be a mistake but, no, there were the letters T-E-R-A engraved clearly on the crown.

I immediately thought back to my only prior experience using a hackamore--on then 6-year-old Helios when he was overdue for a dental exam. We struggled to steer, bend, and change leads, and jumping proved near-disastrous. I assumed the hackamore's mechanics were simply too severe for my sensitive steed. All in all, it was a frustrating experience for us both.

So when I struck up a trot on Tera, I was wary of how well this headpiece would work. I reminded myself to use a guiding rein and ample leg direction but had low expectations of how she would respond. Much to my delight, strong-willed Tera did all I asked and more without argument (this was a first). We had a surprisingly productive ride.

This led me to wonder just how these contraptions work on a horse's body. How can it seem like an elixir for one horse's pulling problem and open a Pandora's box of behavioral issues for another? I couldn't find much published research on the topic, so I called upon a few equine experts for their advice.

Robert Cook, FRCVS, PhD, a professor at Tufts University's Cummings School of Veterinary Medicine and the founder of the "Bitless Bridle," explained that, basically, hackamores' forces act on a horse's nose rather than mouth. The mechanical hackamore that Tera sports, in particular, "uses leverage on the nose, and a curb chain presses behind the chin." Cook then listed other hackamore design aspects that affect this bridle's mechanics, including:

  • The shorter the shank the less severe the pressure;
  • Shanks that curve back are less severe than straight shanks; and
  • A wide/thick nosepiece is less severe than a narrow/thin nosepiece.

"While the hackamore fails to provide a good lateral signal for steering, it does provide a vertical signal for slowing or stopping," he said. "It does this by encouraging the horse to lower his head and flex, the same as a curb (bit)."

So what types of horses take to these types of forces? Those that are not able to wear a bit (due to mouth injury, severed tongue, etc.), for starters, said Hilary M. Clayton, BVMS, PhD, Dipl. ACVSMR, MRCVS, the Mary Anne McPhail Dressage Chair in Equine Sports Medicine at Michigan State University, who has performed tons of performance horse research, albeit not on hackamores specifically. She cited other cases in which trainers simply believe certain horses "go better" wearing this bridle.

She did caution, however, that "horses are very sensitive to pressure on the nose. Riders should be careful not to apply high or continuous pressure when using a hackamore." Cook has even seen improperly used hackamores obstruct horses' nasal passages and fracture nasal or jaw bones.

All told, there seems to be no cut-and-dry advice on exactly when, where, and how to employ a hackamore--except for "do so sensibly." Like most pieces of riding equipment, it's subject to both rider and horse's personal preference (sorry, Helios). I know some people swear by using a hackamore, both for the control it offers as well as the idea of not using a bit in the horse's mouth. What are your thoughts and experiences?