RE: [RC] Sesamoiditis - Susan E. Garlinghouse, D.V.M.
Could the vets on the
list please comment on sesamoiditis and its implications for an endurance
horse. If a promising endurance horse developed this condition, would you
consider it to be the end of his career? Do horses ever recover sufficiently to
be able to do 100s?
Carole Lee
Like any other lameness, the prognosis is “it
depends”. For those not already familiar, sesamoids are the two
bones situated at the back of the fetlock joint, held in place by the
suspensory ligament and a number of supporting sesmoidean ligaments strapping
the whole thing together. If any of these supporting ligaments are
strained, torn or ruptured, the result is sesamoiditis. As with any
ligament injury, if the injury is minor, then the prognosis is better. If
the injury is severe, then the prognosis is a lot worse. Usually, the
recovery period is anywhere from 6 months to a year.
Because fast work places a lot more strain
on the fetlocks (especially during racing situations where late-race fatigue
increases strain even more), sesamoiditis of anything other than the most
inconsequential nature usually means the end of most flat-track racing careers,
or at least provides a very guarded prognosis for return to racing
soundness. Likewise, if the ambition is to do 100 mile endurance rides at
international competition speeds, then I’d be very wary of trying it with
a horse recovering from sesamoiditis---it’s probably just still too fast
for a compromised joint. If the ambition is to complete a 100 mile ride,
and if thought and common sense is used in choosing an appropriate venue (ie, a
flat course would be easier on the fetlocks than a mountainous course with lots
of downhill trotting), then the prospects are brighter.
If you are considering an endurance prospect
that has a history of sesamoiditis, then I would have the fetlock in question
evaluated by a really good equine vet that likes lameness workups and has
digital radiography equipment---I don’t think you can really get good
enough images with just film cassettes. A compromised sesamoid bone
(actually, there’s a pair of them back there) will show bone
proliferation and/or a faint black line running across the bone---sort of like
a fuzzy-looking fracture line, but it’s actually vascular channels that
develop in response to inflammation. Ultrasound of the ligaments would
also be useful, but you really need a good lameness vet to catch
them---scanning the sesamoidean ligaments isn’t something most vets do
every day and you need someone that’s familiar with what a hinky
sesamoidean ligament looks like. Taking the horse to a referral center
would be worthwhile, certainly a lot more cost effective than trianing for
years to get to 100-mile conditioning, only to find out those fetlocks won’t
take the strain after all.
If you’re considering a sesamoiditis
horse as a prospect, also very carefully consider the size of the horse and
rider---now is not the time to ask the horse to carry a HW rider, especially if
the horse himself is already a good size, ie over 1000 lbs at fit condition.
Every extra pound carried down the trail is that much more downward force being
exerted on a suspensory system that just may not be able to support it for the
years it will take you to reach 100-mile capability.
