|According to an
expert from Jessica Jahiel's Horse-Sence,
The Newsletter of Holistic Horsenmanship® at http://www.horse-sense.org/,
the following is her recommendation for pen sizes.
Round pens, known as "breaking pens" or "bull pens", are
often only 35' in diameter. These tiny pens can be useful
for slow unmounted work - for instance, teaching a horse to
tie or lead, sacking out a horse, introducing a horse to
tack. They can also be useful for teaching horses and new
owners the first basics of roundpenning at a walk and jog,
and they can be useful places to turn out a stallion or a
foal to get some air and more freedom and exercise than they
could manage to get in a stall, but that's about the extent
of their usefulness. Even if the footing is perfect and your
horse is warmed up very well before you take him into the
round pen, the tiny circles are just too stressful for leg
bones and joints. This is not a pen to use for fast exercise
or serious lunging - unless the horse is highly trained and
superbly developed physically, it won't be able to move
correctly or even carry itself correctly bent on such a
small circle. And it's definitely not a suitable size for
ridden work. If the horse is carrying a rider, there are
even more demands placed on the horse's legs and balance,
and the size of the pen becomes even more critical.
A "working pen" might be 50' or more in diameter.
This would allow you to work a horse at a walk, jog, and
trot - but probably not at a canter, unless the horse was
compact, balanced, experienced, and well-trained... and it
would definitely NOT be the place to introduce a horse to
the idea of cantering under a rider.
A "training pen" - this is the point at which a round pen
becomes REALLY useful - would be at least 66' in diameter.
A 20-meter circle - the basic working circle for a
low-level dressage horse in the first years of its training,
and a good MINIMUM size of circle for any horse at the start
of its training - would be 66' across, and since horses
don't usually work up against the side of the pen, but on a
track to the inside of the pen wall, I would suggest that
any round pen used for riding be at least 70' in diameter.
If you're going to do a lot of cantering in the pen, it
wouldn't hurt to make it even larger. The size of the pen
needs to correspond to the sort of work you plan to do in
it. A pen 75' in diameter would be ridiculously large for
someone who planned to use the pen only for sacking out and
tying lessons. On the other hand, pens used by trainers who
do cow work are even larger - sometimes four or five times