The pony's first keratoma surgery removed a section of hoof wall and the tumor beneath. The first surgery was done with the horse standing. (World Horse Welfare photo)
What's a keratoma? An irritation in the hoof wall, or perhaps trauma or some other cause, can disrupt the keratinization pattern in the wall. The horn tubules grow abnormally and form what could be called a horn-filled, non-cancerous tumor. Since it is caught under the hard wall, it presses against the soft tissue of the laminae that surround the coffin bone, or may press against the coronary band and disrupt growth. And it would probably cause a horse a lot of pain.
Yet many horses have keratomas and never show signs of lameness. When a radiograph suggests a keratoma may be present in a lame horse's foot, the horse will have minor surgery to remove it; in most cases the horse improves. The cause and treatment of keratomas seem to be of mild interest to most vet practices.
But if you can read the vet journals and farrier books from Europe, you might think we're missing something. Just as the Eskimos have 100 words for snow, they have a word for every specific condition in the foot and keratomas are classified into groups so that they start to sound pretty interesting.
You will agree if you ever attend a lecture by Dr Hans Castelijns of Italy on keratoma surgery; it is a “don’t miss” opportunity. He says that the German vets and farriers differentiate strongly between a regular keratoma, which he says originates at the sole, and a strand-like tumor that runs the entire length of the wall and originates at the coronary band.
Dutch author Rob Van Nassau in his outstanding book Hoof Problems, classifies equine foot keratomas into three types: fan-shaped, toe, and side wall.
In the nipper jaws you can see the vertical strands of the keratoma that was removed in the initial surgery.
Today’s case involves what is probably a strand-like tumor in a foundered pony named Toby that was rescued by our friends at World Horse Welfare (formerly the International League for the Protection of Horses) in England. It took two surgeries to remove the entire keratoma.
As an introduction, the pony was severely overweight and laminitic; when the laminitis pain was relieved, he still had pain in his toe, and radiography showed a defect that was attributed to a keratoma, so surgery was performed (top photo). The process involves removing a strip of hoof wall. Most horses recover quickly and fully. Surgery is usually conservative because removal of hoof wall at the toe can de-stablize the foot.
After he had recovered and the hoof wall healed, Toby started to develop a bulge around his coronary band so the decision was made to go a bit higher with the surgery and remove more tissue and get to the root of the keratoma.
This is probably the strand type of keratoma referred to by Dr. Castelijns. A similar but more worm-like non-horny growth was featured in Hoofcare & Lameness 78 in an article by Andrew Poynton FWCF. While working on that article with Andrew, I found an old 1800s paper that suggested that these strands really were worms that were lodged beneath the hoof wall and were eating the soft tissue, causing great pain.
Settle down for a few minutes and watch Toby go through his surgery under the capable care of vet Andy Williamson at World Horse Welfare's Hall Farm in the United Kingdom. This might be a great video for horse owners to learn about surgery and anesthesia, too. The first surgery was done with Toby standing, but this one was more involved.
It looks like a simple affair to make a video like this but for Mr Williamson to perform surgery with a camera crew hovering over him and all the while speaking into a microphone and sounding coherent is quite an accomplishment.
World Horse Welfare takes their role in educating people about the best possible care of horses very seriously, whether they are working in the scrapheaps of Soweto in South Africa or keeping an eye on horse welfare at a posh three-day event. When they take time out to make educational videos that will help with hoofcare education and offer them to Hoofcare and Lameness readers, I am amazed at the scope of their mission and their service to the horse. And their generosity.
Please take some time to visit their web site and look around; their laminitis prevention work is wonderful. They need your support...they certainly have mine.
To learn more about keratomas:
Click here to see a 3-D cat scan of a hoof with a keratoma.
Click here to download Hoof Wall Resection and Reconstruction for a Tubular Defect by Andrew Poynton FWCF as published in Hoofcare and Lameness Issue 78 as a free file from www.hoofcare.com.
Click here to order Hoof Problems by Rob Van Nassau and study the three types of keratomas.
© Fran Jurga and Hoofcare Publishing. No use without permission. You only need to ask. Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. 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 email@example.com.