Ridecamp: Re: [RC] Another "bone" question

I'm obviously way behind on reading email, but will comment anyway on this
bone development question.  Horses bones stop developing *lengthwise* from
the bottom up.  That is, the bones in the pastern region have already
reached their full adult length very close to birth; the long bones of the
metacarpal (cannon) bones close next (I think they're at 90-something
percent of their adult length at birth) and so on up the body.  The dorsal
processes of the spinal vertebrae are last to close somewhere between 4-6
years, probably later than that in some cases.

However, in regards to changes in diameter in response to conditioning,
that's a lifelong dynamic process.  A lot of people are under the impression
that bone is a semi-dead tissue, but it's actually one of the most active
tissues in the body in regards to response to environment.  There are limits
to how 'thin' any weight bearing bone will get even if the horse spends its
life caged up in a stall; and also limits to how dense bone will get in
response to steady conditioning.  But, any endurance rider that's kept track
and conditions their horse consistently and steadily will tell you of
significant increases in bone as conditioning progresses, often of more than
an inch measured at mid-cannon bone.

So, you've probably already made up your mind regarding the horses you were
looking at---but while bone diameter is worth looking at in a 3 year old,
and checking to see if they're within a reasonable range, I would probably
pay more attention to joint angles and all those things that won't change
with age.

BTW, the average cannon diameter of horses at Tevis  over a several year
period was around 7.5" measured at mid-cannon.  There was no difference
between horses that finished at horses that were pulled for lameness, but
you could probably assume that every horse that even showed up at Tevis had
gone through a reasonable amount of conditioning (with a few exceptions) and
so presumably had enough bone to at least attempt a 100-mile ride.

Susan G

----- Original Message -----
From: "Jennifer Thompson" <jlthompson@xxxxxxxxxxxxx>
To: "Ridecamp" <ridecamp@xxxxxxxxxxxxx>
Sent: Tuesday, October 01, 2002 3:51 PM
Subject: [RC] Another "bone" question


> At what age is a horse's bone structure done developing?  If
> a 3-year old arab has cannons that are a little on the thin
> side, is there a chance of them increasing in diameter by
> the time the horse is 5 or 6, or are they pretty much done
> by age 3?
>
> Looking at a *really* nicely built mare, who is now 4 1/2,
> but the only pics I have are of when she's three, and she
> looks a little light below the hock and knee.
>
> Just wondering...and hoping... :)
>
> Thanks
> Jennifer
>
>
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 Ridecamp is a service of Endurance Net, http://www.endurance.net.
 Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp
 Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp

 If you are an AERC member - PLEASE VOTE in the upcoming By-Laws 
 Election!!!! (it takes 2/3rds to tango!!)

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