The Evolution of the Horseshoe: Nail Holes of Antiquity

Would anyone care to comment on these 12th century horseshoes from the Museum of London? Yes, that's right: 12th century. That means these shoes were hammered out not long after the Battle of Hastings (1066) when the Normans beat the local Brits.

I have a terrific little booklet call "Old Horseshoes" by Ivan G. Sparkes, and it creates a timeline of horseshoe shapes and details, but it certainly doesn't have any nail holes like these shoes have, although he does reference wavy-rimmed shoes to the Saxon period of British history. (Horseshoes are mentioned in the Domesday Book of 1086.)

According to Sparkes, there is evidence that horseshoes were not deviced to protect horses' hooves, as is so often put forward. He claims that the nails were like keys, and were only nailed halfway into the hoof, in order to provide traction; the heel calks were built up to the same height as the protruding nail heads.

What you see in these nail holes is, of course, a spent hole that looks like it was made by a t-shaped punch, but an argument could be made for a t-shaped nail head wearing down into the soft iron of the shoe. If Sparkes' theory holds, the shoe would last much longer than the nails and go through a sequence of nails as they wore down.

If a modern design nail sat in that hole, you'd end up with a semi-fullered (creased) shoe. Various historical references quoted by Sparkes place the introduction of fullering in the mid-16th or 17th century.

Photo courtesy Museum of London.

The Circus Farrier

Check out this detail from an old photo for sale on eBay this week. It's from a collection of photos of the Ringling Brothers Barnum and Bailey Circus in the late 1930s or early 1940s. The credit is given to a photographer in Chicago.

The entire image includes a performer perched on the horse's back while he's being trimmed!

Leading Hoof Researcher Doug Leach Has Died

Dr. Leach leading a discussion group at the 1987 Bluegrass Laminitis Symposium

The leading contributing researcher and author on the equine hoof of the 20th century died on February 10th in Lexington, Kentucky.

Douglas H. Leach PhD authored major studies on the basic mechanics and anatomy of the hoof in the 1980s, and went on to write about racetrack surfaces, exercise physiology, equine locomotion and a dozen aspects of the hoof's physiology. His name is probably the most often seen in reference lists and research citations.

Leach believed that basic studies of the normal hoof were tantamount to studying laminitis or the function of certain shoes, so his papers created a very valuable base on which more specific studies could be built.

A native of Canada, Leach received his Bachelor and Masters of Science degrees at the University of Guelph and Ontario Veterinary College, then proceeded to the University of Saskatchewan to complete his PhD on the equine hoof, which he earned in 1980.

While at Saskatoon, he co-authored papers with Dr. Hilary Clayton, who was conducting research at the Equine Locomotion Laboratory there and also spent a sabbatical year at the Animal Health Trust in Newmarket, England, where he pursued studies of the function of the navicular bone with collaborating researchers Chris Colles and Sue Dyson there.

Leach was so intent on studying the hoof that he learned to read German so he could reference old shoeing and anatomy texts. He collaborated with researchers at Utrecht, Vienna and Uppsala and cheerfully corresponded with veterinarians and farriers from all over the world.

Dr. Leach played a major role in the First International Seminar on Navicular Disease in 1984 and authored a monograph summary of the papers presented there for Hoofcare and Lameness Journal. He was a key contributor to Hoofcare and Lameness in its early years.

In 1990, Leach was appointed to the John S. and Elizabeth A. Knight Professorship in Equine Veterinary Science at the University of Kentucky. The professorship was expressly created to study causes and prevention of equine lameness.

Soon after moving to Kentucky with his wife, Jane, and their three sons, Dr. Leach became ill and was ultimately diagnosed with Pick's disease, a rare and incurable degenerative brain condition.

Reading Dr. Leach's papers today, it is hard to believe that most are 20 years old. The best collection of his papers is in the University of Sydney's 1990 proceedings book Equine Lameness and Foot Conditions; it contains six of Leach's last papers, and a seventh on racetrack surfaces co-authored with Dr. Bill Moyer.

Dr. Leach was 56 years old when he died. There is no way to estimate how different veterinary medicine and farriery might be if he had been able to continue his study of the foot. What he accomplished in ten short years is an impressive mass of work that will be studied and referenced for years and years to come, but which was only the beginning of a brilliant career cut tragically short.

Laminitis Research from the Field to the Feed Room

Research by Bridgett Byrd (M.S., PhD candidate) at Virginia Tech, was used to create this graph. It shows that pastures at certain times of year have specific times of the day when plants contain high levels of non-structural carbohydrates (NSC). This is effectively mirrored by the insulin concentrations of the horses grazing on such pastures, in a similar way to the feeding of high starch and sugar diets. While this research has been available for the past few years, many horses owners have not been informed of the cumulative effects of long-term high-sugar diets on horses, particularly on sedentary recreational horses. (Graph and caption credit Virginia Tech.)

Remember the image in that graph. We have just turned the calendars to March, so spring will soon be here and the time is here to start planning how horses will be managed on spring grass.

This year, thanks to increased educational efforts, many horse owners are seeking advice on how to avoid laminitis caused by spring grazing. Many horses suffer annual bouts of laminitis that can adversely affect the horse’s soundness for months, or may develop into serious chronic laminitis with its many problems.

Nutritional experts, however, caution that laminitis and insulin resistance are year-round problems and that a horse's entire feeding program should be scrutinized, not just the turnout on pasture.

The Waltham® Equine Studies Group, led by Dr Pat Harris MA PhD, VetMB DipECVCN MRCVS, offers this summarized explanation: “Turning certain ponies out onto lush pasture in the spring and autumn is a common triggering factor for the development of laminitis. It is currently thought that high levels of water soluble carbohydrates, (which include simple sugars as well as Fructan – the more complex storage carbohydrate) – and/or starch may be involved in this process.

"Previous research carried out in collaboration with Virginia Tech by the Waltham® Equine Studies Group in 2004 confirmed a link between insulin resistance and laminitis. This work demonstrated that a high starch and sugar diet, that causes corresponding peaks and troughs in glucose and insulin, increases the degree of insulin resistance.

Dr Harris continues: “The new revelations linking pasture directly to the potential risk of insulin resistance have important consequences for certain horses and ponies prone to laminitis and tying up, as well as obese animals that will already have a greater degree of insulin resistance. For these animals it is likely to be safer to feed alternative sources of forage at key times of year.”

Last month, Florida-based Seminole Feeds announced that it would no longer be the US distributor for Spillers brand feed products, which are developed with Waltham research principles. “Happy Hoof”, a high-fiber alternative to high-sugar hay, was one of the products sold by Seminole in the USA. Seminole has launched a new line of low-starch feeds under its “Wellness” label.

Hoofcare and Lameness does not have much information at present for horse owners "orphaned" by the dearth of Spillers products in the USA.

Maine-based Lucerne Farms, makers of the Dengie product lines of alfalfa-based chopped hay in the USA, is now offering high-fiber, low-sugar products for horses at risk for laminitis. The company also offers excellent customer support.

Farrier Convention Update: Competition Alive with New Faces

Farrier competition at Peterborough, England's Shire Horse Show painted by Michael Murfin graces the cover of out 2008 AFA Survival Guide. Everyone thinks it's a photo, but it's a painting!

My energy is fading after standing up for six hours in our booth at the trade show, but the American Farrier's Association today made some history that I thought I would share.

A big part of this convention is the forging and shoeing competition, which this year is being held at a remote location in the big arena at the Kentucky Horse Park, while the convention lectures and trade show are in downtown Lexington.

But you can almost hear the hammers across the miles.

Some joyous faces stopped at my booth tonight to say hello. Today was the preliminary forging (horseshoe making, no horses), which count towards a farrier's qualification (or disqualification) from the "live" shoeing finals tomorrow.

The happy faces belonged to supporters of the Japanese team. For the first time, two Japanese farriers made it to the finals. Also in the finals: two women (congratulations, Raleigh and Sarah!), one American and one Scottish. There is at least one British male in there too. There were lots of new names and faces on the list, which is encouraging.

Competition chairman Myron McLane also told me tonight that the contest went very well and he is looking forward to tomorrow. Sadly, one of the USA's top competitors, former World Champion Austin Edens of Texas, had to scratch today because of a back injury, but said he hopes to compete in just the draft horse class tomorrow.

The convention is an international event even moreso than usual this year. I saw a European plastic shoe company's booth located next to an Amish booth and wondered, as always, about the way that this event brings people from diverse backgrounds under one roof.

A special highlight last night comes to mind. How many conventions have a "jam session" night? So many musicians showed up to play that they didn't even all fit on the ballroom stage. And many of them were superb musicians. There's no group quite like farriers!

From the AFA Convention: Dr Scott Morrison on Hoof Capsule Injury/Distortion

Dr Scott Morrison of Rood and Riddle Equine Hospital in Lexington, KY was the AFA convention's first speaker.

Predictors of a low turnout at this year's AFA Convention could not have been more wrong, if attendance at the convention's first lecture this morning is an indicator of how many people are here.

Kentucky is coated in snow/ice and I know some people were not able to get here, but many hundreds braved the elements!

I attended the kickoff lecture this morning, wedged into a crowded lecture hall. I was privileged to sit next to Blaine Chapman of Lubbock, Texas, son of the late-great heart bar expert farrier, Burney Chapman. Blaine's running commentary at a low whisper was approving as Dr Morrison sprinted through a 90-minute narrated slide show of interesting cases from the Podiatry Clinic at Rood and Riddle Equine Hospital here in Lexington,Kentucky.

Cases that drew the most comments and questions were the ones where he showed correction of negative palmar angles with roller motion shoes and his preference for the use of hoof casts on hoof wall avulsion and heel bulb injuries.

Much of the wall/bulb injury lecture really was based on the encourage of new growth, what Dr Morrison calls the foot's ability to "epithelialize" (generate new epithelial tissue, as in skin; epithelial simply means cells that form the outer lining of an organ or body structure. Endothelium is the inner lining.).

He recommended using tissue-friendly antiseptics, rather than iodine "...and not kerosene" he added with a chuckle.

Inventing another verb, Morrison said he "domes" the foot surface of his foot casts. Under the casting padding on the wall is povidene creme or a similar antiseptic, covered with gauze, with carpet felt under the sole. He also "domed" a wet leather pad before shoeing, inserted hoof packing from a gun, so the pad bubbled outward, forming a domed ground surface.

While some criticize the use of casts, Morrison saw no problem with leaving them on, and was confident in the healthy growth that he would find what it was removed. He said that if the coronary band is not under pressure from weightbearing, the growth will be more rapid.

A big hit was his slide of a racehorse with an interference injury: the front shoe was imbeddedin the coronet of the hind foot. Also food for thought: he showed a severely neglected miniature horse with grossly overgrown hooves.After a cleanup trim, the horse required extension shoes to stand because the collateral ligaments of the coffin joint (and probably the fetlock joint as well), had been so stretched by the deformity.

At the end of the lecture, a line formed to ask questions.