Tuesday, July 05, 2011

On the Case with Austin Edens: Engineering Prevention of Support Limb Laminitis with a Removable Clog Screwed to a Shoe

The plywood "clog" shoe used to treat laminitis can be a tool in itself or it can be a component of a limb extension and support package, as illustrated in this article about a removable clog used as part of a plan to prevent support limb laminitis. The system was designed by Texas farrier Austin Edens.

The Steward Clog was developed by Dr. Mike Steward in Shawnee, Oklahoma as an economical way for him to treat the rampant laminitis cases in his area.

Standard Steward Clog screwed into foot
He wanted an alternative for the horses of owners who couldn’t afford hand-forged heart-bar or glue-on elevator shoes and tenotomy surgery. He succeeded with a disk of plywood that he literally screwed into a horse’s foot. He charged the client $50. When the clog succeeded and he started telling people about it, farriers and veterinarians had to start adding their own high-tech touches to the world’s most low-tech shoe, whether it was casting tape, non-slip bottoms, shock- absorbing soles, impression material, or even plastic strap-on, strap-off versions.

Before we knew it, the once-lowly Steward Clog was turning into a designer horseshoe with a price to match. Not only that: in a few years' time, the clog design has gone full circle: the same concept can be utilized for both preventing and treating laminitis.

My eyes lit up when I saw a photo of a Steward clog of the latter type that looks like it has been to engineering school. And graduated at the head of the class.

Farrier Austin Edens probably chuckled as he set out to build a three-piece system out of a shoe that was conceived as the anti-system shoe. Consider Austin's illogical but ultimately functional design: he added not one, but two actual horseshoes, of two different metals, to a device that was meant to replace the horseshoe. Are three shoes better than one? The horse will decide.

Attaching the clog to a horseshoe so that the clog can be altered, replaced or removed--using a simple Phillips-head screwdriver and without re-shoeing the horse or disturbing its foot--is the bonus that an engineer-oriented mind like Austin’s can bring to the challenge of preventing laminitis.

Remember that the prospects for fine-tuning a shoe on the "good" foot of a horse with an injured limb are limited after the initial shoeing is done with the horse under anesthesia. The horse is not likely to be able to cooperate much in terms of lifting the good foot for shoe adjustment once he is standing. A removable device that screws onto a shoe and can be slid out from under the foot (and back on again) is a practical solution.

Some people still love a challenge; that is what this business is all about. Thank goodness Austin and people like him (and probably like many of you reading this article) are On the Case.
--Fran Jurga


1. I arrived at the vet clinic to find that surgical treatment for lacerated tendons on the injured left front leg of the horse had been completed. The horse was still under anesthesia and the “good” foot had been measured for the application of a support limb laminitis prevention shoe package. The surgeons asked me to add two inches of length to the horse’s right front, or “good” foot to aid in the prevention of support limb laminitis in that foot.


2. The surgeon asked me to elevate the "good limb" two inches so that it was the same length as the limb in the cast. The cast and its wear material on the near fore added almost two inches of length. My job was to extend the contralateral limb beyond the length of the cast limb and to prevent support limb laminitis. Using wood was the best way for me to elevate the limb.

The first step in creating the appliance was a beveled aluminum shoe with side clips, which I made from 1/2” x 1” aluminum bar stock.


 3. The aluminum shoe was nailed on--not an easy thing to do on a leg that is dangling in the air and bouncing whenever the hammer touches it.


4. When I forged the shoe, I made six holes around the perimeter of the shoe, countersunk at 45 degrees. A block of wood (clog) 1.5 inches thick was shaped to the shoe, and also tapered behind the toe of the shoe for ease of breakover. I screwed in six 1 5/8” long wood screws through those holes into the wood. They held in the wood at 45 degrees, giving a good hold across the clog. A simple Delta Challenger horseshoe was nailed (with horseshoe nails) into the clog to prevent the soft wood from wearing.


5. One of the final steps was to pour Vettec’s Equipak into the cavity of the sole, filling up any space that existed between the foot and the plywood. This was a little awkward to do. I used Play-Doh for a dam to hold it in the foot.


6. This closeup shows the countersunk screw insets at the toe; there were also two at the heel and two at the quarters, all set at 45 degrees, to anchor the wood onto the shoe.

7. The final step, once the EquiPak was set up, was just for insurance. I wrapped the extension in Equicast casting tape.

 About support limb laminitis

Laminitis is usually thought of as a disease with a medical basis, but it can also be caused by mechanical conditions. Both excess concussion, known as road founder, and lack of movement can result in a disruption in the metabolism of one of more of a horse’s feet. The most common scenario is when a horse injures a leg and the opposite, or contralateral, limb bears more than its share of weight. The horse may not shift weight regularly off the “good” leg, or there may be some circulatory or other reason why the laminar junction of of the hoof wall-coffin bone interface becomes compromised. Because the horse may be unable to shift its weight away from the pain of the laminitis, support limb laminitis is especially painful for a horse.

In order to prevent support (contralateral) limb laminitis, many equine hospitals routinely apply heart-bar shoes or go through a special protocol to pre-emptively shoe or cast the good foot when the horse is in surgery for an injury.

 About Austin Edens

Austin Edens is a farrier who is based in Dripping Springs, Texas, and Wellington, Florida, but you might run into him almost anywhere in the world. He is widely known as one of the most successful and consistent international farrier competitors in history (including being World Champion) and a popular judge. Austin’s farrier work today is centered on a sport horse client list and challenging veterinary collaborations such as the one illustrated in these photos. He is also a product consultant and clinician with Delta Mustad Hoofcare in the United States.

On the Case is a new feature of the Hoof Blog. Brief photo- or media-based problem-solving reports on cases from subscribers will be featured. Text and photographs © 2011 Hoofcare Publishing.

© Fran Jurga and Hoofcare Publishing; Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission. You only need to ask. This blog may be read online at the blog page, checked via RSS feed, or received via a digest-type email (requires signup in box at top right of blog page). To subscribe to Hoofcare and Lameness (the journal), please visit the main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found. Questions or problems with this blog? Send email to blog@hoofcare.com.  
Follow Hoofcare + Lameness on Twitter: @HoofcareJournal
Read special Facebook-only news on the Hoofcare + Lameness Facebook Page
Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.