Shunted heel / caudo medial overload management

Equine Podiatrist: Helen Stowell

Horse: Warmblood Mare

Case History: The mare is a talented dressage horse, but her owner had always been concerned about her feet.  Her strong loading pattern into her medial heels, resulted in distortions in her whole hoof capsule. 

The owners had previously tried shoes, which resulted in some alarming quarter cracks originating at the coronet band, so the shoes were removed and the horse self trimmed for a while, but the distortion patterns worsened along with the owner’s concerns.  An EP was called in.

This quarter crack uniquely started from her coronet band

Assessment: From the solar and palmar view, it was clear that on both front feet the medial heels were being displaced compared to the lateral, with the medial walls underrunning and the lateral walls flaring.

The hoof wall distortion suggested an overload of the medial heel and an underload of the lateral.  

When the pastern and fetlock is flexed through its range of movement, the medial heel moves over to the centre line of the limb, so her conformation was setting up that pattern.

Right Fore, palmar photo showing heel asymmetry.

The EP had recently been exploring the work of Hoof Architect, who has been characterising common hoof distortions and why they occur https://thehoofarchitect.blogspot.com/2023/09/demistifying-equine-limb-deformities_21.html

The mare was a clear caudo- medial overload case. These often have a lateral offset to the coffin bone, and a non ground parallel joint plane in her coffin joint (and higher) because of asymmetry in the pastern.  Hoof architect describes how P3 is sitting into a medial roll which means it’s dropping downwards in the hoof capsule on the medial side, and is likely to be over-pressuring the sole in the medial toe quadrant of the foot.  Meanwhile at the lateral toe quadrant P3 is rolling up and away from the sole.  

At the heels, the shunting of the medial heel means that more of the lateral cartilage had become adjacent to hoof wall than would normally be true.  Its likely that’s the reason why the mare developed cracks at the coronary band when shod, as the lateral cartilage was sitting against the hoof wall and there was no space for it to expand normally, so a strain pattern was put into the coronary band /top of the hoof wall instead.

Trim Protocol: In her webinar with the Equine Documentalist, the Hoof architect recommends a trim protocol which adjusts the toe plane to counteract the medial roll of P3 and a heel trim to counteract the shunting of the medial heel.  That protocol is behind a pay wall so won’t be fully explained here, but it’s worth subscribing to the webinar to go through the detail.  

Suffice to say that it’s an unusual trim, because it chooses to not put the foot on a single plane.

In this post trim photo you can see one aspect of the approach – how the shunted heel is trimmed to a lower  plane than the remainder of the foot.  When the limb is loaded then the heel can descend.

Right fore, trim applied

In a case like this, it’s a voyage into the unknown in terms of whether making big changes to her hoof, joint and limb balance is of benefit to the horse or not.  Because the mare is in such a high level of work, with such a skilled aware rider,  the EP and her owner used how she felt in her schooling as a measure of success.  Had she shown issues or reluctance to work then we would have rethought the approach.

Results: The results were encouraging, with the disparity of the heels improving, and the distortions at the toe reducing.  Crucially her willingness to work in the school improved – shortly after these photo’s were taken the mare was able to offer her rider the first attempts at two times tempi changes.     

Since the overload pattern is set by her conformation, this isn’t a ‘recover’ situation, but we’re pleased to have figured out a better set up for this mare. She is now trimmed every three weeks to maintain the balance we’ve achieved.