>The only way for a pacing horse to interfere that I can imagine is if the >left rear should strike the right fore, or the right rear should strike the >left fore. In a well-conformed horse, there should be plenty of spacing >between the legs, and the leg shouldn't come very close to touching. Legs >come much closer to touching (and thus closer to interfering) in trot or >canter.
-it is enoughf that there are a slightly sloop on track to let a horse interfer just in that way on high speed pace!!! Malin in Iceland
