Any stories about horses who have cracked a cannon bone? Interested in the good, bad and ugly of long term soundness. Just found out my OTTB came off the track in 2016 due to this, I wasn’t told when I bought him Oct 2017, he passed prepurchase but I had no xrays. No clue if he was casted or had surgery. He has been fragile, mostly for benign reasons like abscesses, but fragile all the same. I’m having a vet out to evaluate just wondering if these things ever turn out well (and I understand it depends on severity, where, how etc.)
A lot depends on the details, obviously, but one of the more common things I think of hearing “cracked cannon bone” is basically a really severe version of “bucked shins”. Official terminology is “dorsal cortical stress fracture” for that kind of injury. Short term prognosis (return to race performance) is good if they are managed properly (although many might be retired if their race performance was “meh” and their connections don’t want to invest in full rehab and return to race-level training). As far as I know there are no long-term sequelae in a second career, other than maybe a blemish/bump if it was treated with a screw (they often are not) and the screw head is large enough and close enough to the surface to be palpable, or if the healing bony response was particularly marked and doesn’t remodel back down. Ideally try to get previous records and radiographs. Current radiographs will tell you a lot about where it stands now. If you’re really anxious that there are ongoing possibilities for stress fractures you could get a bone scan, but that’s probably overkill for most second-career horses since the workload is generally much lighter. I did know one eventer that would get a scan on her four-star horse after initial Spring conditioning, before the season started, to make sure everything was copacetic (we never found anything).
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“Condylar fracture” would be another common possibility. Also a stress fracture process. Treatment and prognosis is more variable depending on the specifics than for dorsal cortical stress fractures. Being described as a “crack” for this type of fracture would suggest an incomplete fracture (but who the heck knows), which generally have a good prognosis for return to racing and an excellent prognosis for a second career. Complete fractures can be more iffy both short and long-term since there’s more likely to be an irregularity in the joint surface that would set up for osteoarthritis over time. Again, ideally get old radiographs and records, but getting radiographs now should clear up a lot of questions, and hopefully put your mind at ease.
Very, very generally speaking, these types of bone injuries do a lot better than a whole lot of the soft tissue injuries. People think of bone as a static, rock-like material that stays damaged once it’s damaged, with repairs only holding together because of the hardware put in surgically. It’s not; it’s highly dynamic (particularly in young horses) and completely replaces and remodels itself with bone tissue that is indistinguishable from the original tissue, over time. Tendons and ligaments don’t have a lot of blood supply and have very poor mechanisms for healing and remodeling; sites of injury are replaced with a kind of substitute tissue that is never quite the same as the original.
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I can’t give you great details because the horse isn’t mine but there is a young OTTB that fractured (completely through the bone) his cannon bone at my barn. He was given a 50/50 chance of coming back to full work after the rehabbing process. I know he has to wear therapeutic shoes but otherwise is 100% sound. His owner is planning on a full show season and getting him through Prelim this year.
A third option is a saucer fracture (usually as part of a severe bucked shin)). I thought those were often tricky, mostly because those sorts of bucked shins never really resolved fully under racing. <— I bet this is the same thing toblersmom is talking about now that I read that post!
In my old and feeble memory, condylar fractures usually had a great return to racing prognosis unless they were in/near the joint space.
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I’ve known several…never caused an issue. The issue is letting them heal. Once healed…wouldn’t bother me at all in buying a horse. The two I had were not ever even lame on them…which is why people often start them back too soon. It’s not like a soft tissue injury. One I was given and they told me he could be turned out and go back to work. I had my vet out and xrayed it …nope…two more months stall rest (re-xrayed twice) then I let him hang out in a field for a month. Was almost to the core…but once healed, never an issue. But it was the second time he did it while racing and it was probably because they started him back too soon. But it absolutely wouldn’t scare me away from a horse unless his conformation was sooooo terrible that I thought it was the likely cause.
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I had one with a saucer fracture, I believe it was from a kick in turn out. He recovered 100%, went back to prelim eventing/3’6 jumpers. It was slow to heal as noted above–I think mine was in the stall ~4 months even though the initial estimate was 2.
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My old hunter/eventer/dressage horse had a fractured splint, just below the hock, with a hairline fracture of the cannon. The cannon bone fracture was the lesser injury. Had the splint fracture been higher, he would have had to be euthanized. It was eight months of hand walking, but he came 100% sound. I did not return him to jumping (my choice), except what we ran into on the trail, or the occasional “hunter hack” class, but the vets all passed him as sound and able safely to return to jumping. He lived to be 24 and was retired at 22 due to arthritis (nothing to do with the fracture). He could still have been trail ridden, but retirement seems a better option at the time.
If it’s been that long, it should be long healed. But would be interesting to know if there’s a screw in there.
I have a horse who had a hairline fracture in his cannon bone, it did spiral slightly but was still considered a cortical fracture.
The prognosis was always good. He did spend 6 months in a stall with handwalking. I did only turn him out before for 2 weeks before I lightly started hacking him (hacked for 30 days) and slowly went back to work.
He had done a BN or 2 prior to his injury. He’s now going training level with much more scope. The leg has never been an issue. It’s been about a year and a half.
Thanks everyone for your experiences, I had the leg expert in our area come out and do some x-rays, he said it was a saucer fracture and that it healed well. He wasn’t concerned about it and gave no limitations. His problem at the moment is a re-do of the last fall’s abscess, apparently the local vet didn’t pare away enough and it created an “internal quarter crack”, only visible on x-ray, where the lamina detached from the hoof wall from slightly below the coronet all the way down to the ground. He pared away more and it will just have to grow out. No big deal but annoying.
Racehorse wins over jumps after having had surgery for a cannon bone fracture.
