Myth Busting - the "External Abdominal Vein"
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Here is my rendition of a picture which has circulated on the internet for a while, claiming to show where the “external abdominal vein” lies. The theory is that you have to have a short cinch so your cinch buckle doesn’t sit over it and stop blood flow through this important vein. The picture and idea come from a pdf advertising cinches. I won’t copy the real picture for copywrite reasons, but if you google “external abdominal vein” and Parelli you will find the picture and the (very erroneous) explanation that goes along with it.
But did you notice something? While I have drawn in the “external abdominal vein” where they have it, there is actually a real vein inches below the drawing.
And not just on that horse. It’s there on this one too.
And this one too!! Sometimes it is more obvious…
And sometimes it is less obvious…
But it is always there. Hmmm. That’s odd… Well, not really, because the original picture and the information alongside are totally incorrect. There is no external or exterior (depending which side of the page you read) abdominal vein as such at all, and there certainly isn’t one over the thorax! But there is an exterior thoracic vein which joins a superficial thoracic vein. And it runs, well, right where you see the veins on real horses…
The idea behind the write up is that you need to avoid having your cinch buckle run over this fictional vessel, so you don’t block it and impair the circulation.
So you should buy one of their short cinches and have the latigo run over the vessel instead. Which means putting the cinch ring really close to the elbow where the likelihood of causing cinch sores is higher... No. Not a great idea...
The truth, of course, is that the real vessel is well below their drawing, and it is the wider cinch that will go over the vessel, which is the best thing anyway. (Something about that whole pressure-distributed-over-a-wider-surface-area concept I’ve heard somewhere before?) So you can totally disregard anything you read or hear about this fictional blood vessel and all the issues it will cause. It just isn’t an issue.
Unless you are tree makers and create a weird set up like this to test pressures under trees. In that case, you just might have the cinch ring crossing the vessel. (I found this photo when scrounging around my computer for pictures for this post today and had to laugh... And no, that tree doesn't fit the horse well, which is why we were testing it.)
For the anatomy fanatics, here’s the real anatomy. The external thoracic vein (#31) collects blood from the superficial tissues over the thorax and the cranial abdomen before joining other branches and becoming the superficial thoracic vein (#30), which goes forward and joins other vessels before going through the thoracic inlet into the chest and back to the heart.
The above illustration is from Goody’s Horse Anatomy, which is a good basic anatomy book, especially for its price. Getting something like this will allow to you check out the sales pitches based on “anatomy” that seemingly abound these days. Besides, anatomy is fun!
PS. I did more research and followed up with another post here.