09/13/2025
We will go out on a limb hereโฆ
Horses need their ribs to be functional.
That should not be a shocking or controversial topic, yet it is. Clinical significance of ECVM is highly controversial between veterinarians. ECVM horses are sometimes missing their first ribs.
I have heard the excuse that these horses have an anatomical variant. That if it was clinically significant or a malformation they could not be competing. That if they can compete with it- it must be a โnormal variantโ and not a malformation. If that is the logic used then that rule must stand for all โ navicular, hock arthritis, OCDs, kissing spine, neck arthritis. As those are all accepted clinically significant diseases. We recognize that horses can be born with, develop early on, or can occur with use but yet often do compete successfully with these conditions.
Yes that missing rib and malformed lower neck can be the cause of pain, reactivity, lameness, girthiness, behavioral concerns, tripping/stumbling ex. Yes, it is a significant diagnosis, similar to the rest mentioned above. Some horses can be managed to have successful careers, and some cannot. However, missing your first rib, having your ventral neck muscles malformed and compressing your brachial plexus in the wrong area is indeed clinically significant, no one will ever convince us otherwise.
All to often, owners have been told heir horseโs necks were normal, but yet the malformation is present. Owners, trainers, and veterinarians who cite one paper determining that ECVM is not clinically significant, ignore their horsesโ clinical signs, and discredit ECVM as a possible clinical cause - will always be invited to come see a necropsy with Rexos. Not all ECVM horses are unusable, similar to kissing spines- some struggle while others do not. They all however need support, management, and to be heard when they give subtle signs of pain. When you necropsy a horse who is clinically affected - their bodies so vividly tell a story of disfunction and pain. These horses show their stories of pain so clearly in necropsies. They can have one or more missing ribs, incorrect muscle attachments (thus biomechanics affected), serious nerve entrapments, trachea malformations, and more. It is impossible to walk away thinking this is not clinically significant.
Photo of rudimentary first rib, with abnormal brachial plexus placement trapped under. Yes that would be painful and cause tripping/forelimb lameness.
