ARCHIVE - ARTICLES 2008

Dec 08 - The impact of modern materials on 21st century farriery?

 

Archive - Forge Magazine - December 2008
The impact of modern materials on 21st century farriery?

By Andrew Poynton, FWCF

Down through the centuries farriers have been innovative and creative in their work to keep horses sound and in work. Admirable and effective techniques to not only shoe, but to repair compromised hooves have been practised and proven. The mentality of the progressive farrier has not changed. With the development of, in plastics and adhesives these age old problems can now be treated in simpler and more effective ways.
Rather than trimming and shoeing limited primarily to the bearing surface of the horse’s foot, the realm of the farrier/practitioner’s operation has developed to involve all the structures of the hoof; he or she can have greater influence on recovery of deformed or broken hooves and generally weak, problematic feet. So, when using lightweight materials that can be moulded and sculpted to the hoof, which more closely assimilate the structure and function of the hoof capsule, not surprisingly, the results and the scope are much wider.
To illustrate this, Andrew Poynton, FWCF, presents the farriery treatment of three case studies where modern materials are employed to achieve an effective safe and often, he says, accelerated recovery. The three cases involve a chronic laminitic, dorsal hoof wall separation and corrective shoeing in a foal.

CASE 1 - Condition: Severe chronic laminitis; Patient: Tilly, 9-year old Welsh cob mare

Brief History

The mare suffered acute laminitis in March 2007; she was approximately eight months pregnant. The hind feet were most severely affected, possibly due to the extra weight of the foal. The foal died at birth; the mare spent 12 weeks on a wood shaving bed, much of the time recumbent. She had extensive infections in both hind feet. The feet were x-rayed in June 2007. The prognosis was poor and euthanasia was considered.
The veterinary surgeon, Kate May of Stable Close Equine Practice, asked AP for an opinion. The owner wanted to try any option that may save the mare. While the case was severe it was the opinion of AP that it need not be a terminal case; all parties were committed to give it their best, subject to being able to manage the infections and pain level of the mare. Cases similar to this may well recover, but recovery could be described as a roller-coaster ride, with a somewhat undefined destination until some way into the journey.

Materials

Surgical spirit, sugardine, wound dressing, antibacterial wax putty, Imprint First low melt thermoplastic shoes, Imprint Structural Adhesive Methylmethacrylate type (MMA), low melt thermoplastic granules, refrigerant spray, farrier’s tools and a high-speed cutter.

Treatment

After referring to the radiographs (see page 5) the right foot was trimmed to re orientate P3 to more ideal balance; the detached toe forward of P3 was cut back at 45 degrees to remove leverage, and medicated bandages and gauze with sugardine were placed over the sole where pedal bone had perforated. The shoe was then moulded on. The attachment was to the side walls only. This was carried out in a gentle manner without the need for nails. This provided restored phalangeal alignment, elevation and protection to the perforated sole and a frog cast to support P3.
Just distal to the coronary border, in the front half of the hoof, a horizontal resection approximately 15 mm deep was made from where the wall had already detached but was jamming the coronary corium; this would alleviate the constriction and allow new horn growth. The mid section of the dorsal wall was not removed, as in doing so at this stage the whole hoof capsule would become destabilized; it still had a use in forming a bridging arc to hold the two sides of the hoof together.
The left hind had different problems – under-run sole and infection running up the dorsal wall. Infection had blown out of the lateral heel bulb. The whole sole had dropped and perforated. The coronary border had not broken but there was a depression there so no horn was removed in this area, but the toe was cut back on the horizontal plane by up to 50 mm. The mare was given some sedation for the second half of the treatment. The front shoes were taken off and feet trimmed, this was sufficient.

Initial result

Cautious optimism as the mare had to grow two new hind feet. Once the shoes were in place the mare seemed to stand relatively comfortably. Overall it was an epic job.
On the second visit the remainder of right hind detaching hoof wall was removed. After thorough debridement and disinfecting with surgical spirit it was rebuilt using the Imprint Structural Adhesive (MMA) and low melt thermoplastic. When this was cured the shoe was welded onto the plastic hoof. This provided a replacement hoof capsule while the new horn grew down and the sole regenerated.
The left hind had scant wall remaining, so it was rebuilt in a similar fashion. When applied, the plastic is hand warm and only cools as it hardens making it safe and useful for substantial hoof rebuilds.
On subsequent visits the feet went through various stages of recovery interspersed with infections deep at the toe and into P3; these were dealt with using good drainage, nursing and antibiotics. The mare is a plucky fighter, and remained bright most of the time. For seven months she spent most of the time in her stable, walking out occasionally. She then progressed to being turned out in a small short cropped paddock for an hour or so most days.
The second radiographs (May 2008) were taken just prior to re shoeing. They reveal a healthier position of P3 but also show marked degeneration to the lateral toe quarter of the bone due to the deep recurring infections. There is also some remodeling to the extensor process. Despite this, both feet healed and the mare is happy to canter around the paddock. The case was handed back to her regular farrier Mark Barton after almost exactly one year, and he continued her care with the Imprint First shoes and then progressed onto the Imprint Sport shoes as her owner wanted to get her back driving again. It was recommended that Tilly should remain in shoes with frog support, and minimising concussion would also be beneficial. She is currently shod in front with steel shoes and Imprint Sport on the hinds. It was very pleasing to see her trotting out boldly in October, 2008.

 

Captions from left to right, top to bottom: 1. Tilly; 2. First radiograph; 3. Fitting first shoe; 4. Solar view Imprint first shoe;
5. Left hind second visit; 6. Left hind ten months later; 7. Left hind; 8. Radiograph 11 months later prior to shoeing;
9. DP View showing P3 damage; 10. Right hind second visit, before work; 11. Second visit hoof rebuilt.

 

CASE 2 - Condition: Dorsal hoog wall separation; Patient: 2 year old thoroughbred coltMaterials

Imprint Sport shoe, Imprint Granules, Imprint Structural Adhesive Methylmethacrylate type (MMA), low melt thermoplastic granules, refrigerant spray, farriers tools, high-speed cutter. Keratex wax hoof putty, surgical spirit and cotton wool.

Report

This colt had a right fore hoof defect, which undermined the hoof wall to within 25 mm of the coronary border of the hoof to the ground border, affecting the lateral toe quarter to the centre. The hoof was becoming upright; the coronary border bulging forward at the centre of the toe, with a crease at mid wall level, and the hoof wall was overlapping causing laminal trauma. The hoof flared medially and was upright on the lateral side. This colt was lame in training.

Treatment

The area was debrided and the meshing edges divided. When the preparation was virtually complete, a blood vessel was caught at the toe of the hoof, so that area then needed to be left open. It was isolated using Keratex putty to keep it free from adhesive or other contamination. The hoof wall was reconstructed leaving a small area where the foot was bleeding, and an Imprint Sport shoe was fitted. The shoe was fitted slightly full on the lateral side and close on the medial side to achieve a central base of support.
To balance that the left fore was shod with the same size shoe. The trainer was advised not to work the horse, certainly until the horse was comfortable and concentrate on his hoof recovering and reforming into a normal shape before going back into full work.

Four weeks later
Report

After discussion with the veterinary surgeon, AP discovered that the colt had had five days off work following the first visit. The colt had gone back straight into work, on the horse-walker and on the gallop and as far as the trainer was concerned he was in full work. The horse is sound and the foot is growing out. AP expressed some concern at the level of work.

Treatment

AP removed about 80 to 90 per cent of the hoof rebuild, as it seemed to be getting partially undermined and moisture was trapped and running up behind. It was excavated and replaced and the complete defect filled. Keratex putty was only used in the very deep crevice near the centre of the toe but it was filled over with Imprint granules and sealed within the hoof. The shoes were then fitted. What was noteworthy was that both shoes were firmly in place, minimal signs of wear and no sign at all of any breaking away at the rim; the horse continues sound in work on a gel track, all-weather surface. The hoof shape has improved, the buttress angle has receded becoming closer to a straight line in the dorsal hoof wall.

Result

The horse is sound, having been shod once a month and the defect is growing out quickly. The trainer is pleased.

Captions from left to right, top to bottom: 1. Before treatment; 2. Foot debrided with adhesive and sensitive area isolated;
3. Plastic moulded in place and wall keyed for shoe attachment; 4. Work complete, first pair of shoes;
5. Hoof rebuilt and stabilised, with drainage.

 

CASE 3 - Condition: Flacid flexors - hind limbs; Patient: 3 week old Warmblood filly foal

Materials

Imprint foal shoes with caudal extensions of 60 mm – Imprint Structural Adhesive Methylmethacrylate type (MMA), Imprint Granules low melt thermoplastic granules, refrigerant spray, farrier’s tools, high-speed cutter, surgical spirit.

Report

The filly was weak in the hind limbs from birth. Although they had strengthened to some degree, they needed help to ensure she developed normally without permanent hyperextension of the flexors. The foal walked with the toes in the air, bearing on the heels only.

Treatment

No sedation was used. The foal was quite boisterous, but containable. The hooves were trimmed then multiple micro indents were made in the lower hoof wall with a 2 mm high-speed burr; the feet were then cleaned using surgical spirit. Adhesive was applied to the hoof, before the shoe (with softened foot mating parts) was moulded on and cooled. The caudal extensions were aligned with the spine as opposed to the feet, and the sides were sloped (to reduce the chance of being trodden off).

Result

Immediately the shoes were in place the foal stood with toes on the ground and a reasonable hoof pastern alignment. Two pairs of shoes were fitted to effect a satisfactory result at three-week intervals. The shoes remained well attached until they were removed. The lightweight plastic reduces chance of interference injury.

Captions Left to Right, Top to Bottom - 1. Before treatment; 2. Hoof preparation; 3. Shoe fitted with extension;
4. Showing caudal extension, left hind; 5. Hind stance with extensions fitted; 6. Right hind solar view.