Q: I'm concerned that I may be too heavy for my horse. Staying fit is a constant battle for me, and right now I weigh 175 pounds at 5 feet, 5 inches. My Quarter Horse-cross gelding is 14.1 hands, but sturdy at about 900 pounds. Am I too heavy for him?
-Laurie Handley, Nevada
A: Laurie, the basic rule of thumb for a horse's weight-carrying capacity is 20 percent of the horse's weight, or, say, 200 pounds for a 1,000-pound horse. (Two hundred pounds would be an approximate upward limit, not an average of what he can carry.) That means a 900-pound horse like your gelding, in general, shouldn't be expected to carry more than about 180 pounds, including tack, to avoid putting excessive stress on his joints and ligaments.
(Obviously, this rule of thumb assumes that the horse in question is at a healthy weight. A horse that's grossly overweight at 1,200 pounds, for instance, can't necessarily carry 240 pounds.)
All that said, there are many variables that affect this rule of thumb. One would be the type and build of the horse, regardless of his overall weight. A tall, relatively lightly built horse that weighs 900 pounds is, in general, going to be less able to carry weight comfortably and safely than a 900-pound horse that's shorter and more compact?in other words, sturdy, like your gelding. The amount of bone a horse has?meaning the size of his weight-carrying large bones, as indicated by the circumference of the cannon bone?is closely related to the sturdiness factor. The more bone, the better, with respect to a horse's ability
to carry weight and stay sound.
Then, too, your overall fitness (as opposed to just your weight) is also a factor. A strong, fit, well-coordinated but heavier rider can often be easier for a horse to bear than a weak, unfit, awkward but lighter rider.
Your riding ability comes into it, as well. Skill and experience will enable you to be better balanced at all times, which makes you easier to carry at any weight.
So, overall, assuming that (1) you're reasonably fit for riding and have good basic skills; (2) your horse is indeed a sturdy fellow with reasonable bone; and (3) your tack doesn't weigh an additional 100 pounds, you should be fine.
-Barb Crabbe, DVM
H&R Consulting Veterinarian
Author, Comprehensive Guide to Equine Veterinary Medicine (Sterling Press)