Cutting-Edge Hoof Education
Described by host Ric Redden, DVM, founder of the International Equine Podiatry Center in Versailles, Ky., as "probably the most harmonious learning event in the world," the Bluegrass Laminitis Symposium held annually in Louisville, Ky., is a mecca for farriers and veterinarians interested in expanding their knowledge of the pathological equine foot. "This is an intense, informal learning experience," he said in his opening remarks. Attendees (many of whom come every year) tend to be the most sought-after shoers and veterinarians in their geographic areas for foot problems because of their desire to learn and their exposure to the experience of those, like Redden, who make treating these problem horses their lives' work.
Their next goal is to spread the word about proven new techniques and proven principles, educating both colleagues and clients. "Everyone accepts the principle of 'no foot, no horse,' but they don't always practice it," said one attendee. "We've got to keep putting the information out there."
Club Foot Experience
The first presentation was on the club foot--a problem seen in all breeds. The club foot is characterized by higher hoof angle than is normal for that horse due to an increased pull of the deep digital flexor tendon (DDFT) on the bottom of the coffin bone.
Redden discussed the etiology of and his treatment experiences with club feet, beginning with an account of his grading system. "It makes no sense whatsoever to talk to anyone about a club foot without a reference point," he stated.
"A lot of people say they don't see low-grade club feet--but that's because they don't have their trifocals on," said Redden. "You've got to look at these feet for the early changes. The foot might be three to five degrees steeper than it was, the frog might be atrophying just a bit, the pastern might be getting just a little bit out of alignment, and the shape of the bars might be changing a bit."
Correcting the Club Foot--"The club-footed horse is bearing weight at the toe on tissues that aren't designed to be abused," he said. "The heel is designed to be abused, but isn't even used (for weight bearing) in the club foot. You can't change these things with a rasp. You want to load the back of the heel and unload the apex (of the coffin bone, also called P3). Think of going inside the foot and lifting the apex off the sole, not of making the foot look better.
"You have to take an X ray of the club foot to see what makes that foot look like it does," Redden recommended. He discussed various shoeing solutions, primarily focusing on his rock and roll shoe. Cutting the DDFT and/or its check ligament was also discussed for various situations. The biggest factor, Redden said, is shoeing treatment prior to surgery as well as subsequent resets. "You need shoeing mechanics to augment the tenotomy," he stated.
"The force of the DDFT affects every pathological problem in the foot," he explained. "Manipulate the forces of that tendon, and you can create a better healing environment for most any pathological problem." (For more information and drawings of the various club foot grades, see article #4073 online.)
High-Scale (Severe) Laminitis
"When the (coffin) bone sinks 15-20 mm, the hoof becomes a tourniquet that shuts down the vascular supply and can kill the horse," said Redden in his presentation "Treating High-Scale Laminitis With Wall Ablation and Transcortical Cast." Redden is known for his aggressive, groundbreaking treatment of severe foot problems, and this presentation certainly was in character. "Take (the wall) off, but first make sure the venogram shows you it's a good candidate." He detailed his approach in identifying candidates for hoof wall ablation (partial or complete removal), the procedure, and what can be expected in the aftermath.
"You have got to get that Day 1 film," he urged. "It's not that one that's so informative, it's the one you take a few hours or days later where you might see the changes."
Venograms--"A venogram is the only way I can accurately assess the degree of damage at this or any other stage," Redden stated. "When the venogram shows a foot that's basically depleted of the vital blood supply, the primary emergency goal is to restore adequate blood supply to the digit before irreversible damage has occurred."
Hoof Wall Ablation--Restoring blood flow to the damaged areas means removing whatever is restricting blood flow, which can mean taking off part or all of the hoof wall. With the edema (fluid swelling) and pressure between the coffin bone and the inner hoof wall common to acute cases, chronically non-responsive cases, chronic suppurative (oozing at the coronary band) cases, and in cases where the hoof is about to slough anyway, the damage has all but destroyed the attachment of the hoof to the bone, and the bone is rapidly dying. "When you have 10 mm of sinking and 5-10 mm of swelling in a rigid hoof capsule, it makes a pretty good tourniquet," Redden said.
"I've used my partial decompression technique to include lower wall resection, upper wall resection, and internal decompression technique (deep flexor tenotomy) followed by realigning the palmar surface of P3, all with reasonable success," he continued.
Redden has found that moving quickly to restore blood flow minimizes damage to P3 from the loss of blood flow; this damage drags down the prognosis substantially, he noted. He had removed entire hoof capsules on eight horses (13 feet) by the time of his presentation, and five were recovering.
Following full wall ablation, he applies a walking cast built around transcortical pins (inserted through the cannon bone) for weight bearing.
Prognosis--"All cases have shown immediate clinical relief, and most cases have cornified the laminae (developed horn tissue over the sensitive laminae) within the first three weeks," he reported. "The response is always relative to the degree of damage that's already present."
"Five to six months is required for the majority of the primary horn tubules to grow from coronary band to the sole surface," he went on. "The sole and frog regenerate very quickly. It is very obvious that timely decompression of high-scale cases is a viable option, especially when cases are facing euthanasia as the only other option." (For more information, see article #4247 online.)
Understanding the Venogram
The venogram (a procedure for visualizing blood flow within the foot) has been acclaimed as an essential tool for treating lame horses, especially laminitic ones. In "Aspects of Normal Digital Venograms: Anatomy, Parameters, and Variations," Amy Rucker, DVM, of the University of Missouri, discussed this procedure with clear illustrations, venogram images, and video to provide what one attendee described as "exactly what we need in order to understand this better."
"The venogram is a very simple procedure that allows you to assess a horse, develop a tailored treatment program, and assess the horse's progress," she said.
She used several cases to illustrate the initial presentation, venogram appearance, and follow-up venograms' value in assessing the healing process. She also presented tips for taking consistent, ideal venograms.
Venogram Safety--Some people have voiced concern about the safety of injecting the concentrated radio-opaque solution into the foot of a horse which might already have circulatory problems. Several informal safety studies done by Rucker at the University of Missouri suggested that they were safe. Also, they apparently did not affect hoof growth on normal horses, although Redden believes that they might stimulate growth in some problem feet.
"Our goal is to understand the relationship of the bone, soft tissue, and blood supply," Rucker concluded. "Then we can discuss the wide variations of normal." (For more information, see article #4076 online.)
Venogram Technique and Artifacts--Rucker later discussed venogram technique and artifacts (misleading elements) that can be seen with poor technique. For a full description of these with images, and a step-by-step procedure for taking a venogram, see articles #4248 and 4249 online.
"If a horse needs an amputation or he's not going to live, that's not much of a choice," began Redden. "Horses with catastrophic injury or disease of the lower limb are most often euthanized as there is irreversible vascular, soft tissue, and bone damage. Amputating the limb well above the dysfunctional area and fitting the horse with a prosthesis is a viable option."
Selecting a Case--The ideal candidate is a young horse with catastrophic laceration and/or fracture of the hind limb where the injury is less than four weeks old, Redden said. Less ideal candidates have chronic septic joints of more than eight weeks duration, chronic forelimb injury or disease, and cases of unilateral (one limb) injury with contralateral (opposing front/hind) limb laminitis. He added that catastrophically injured young racehorses, with their fitness, would likely be good candidates.
Amputation Procedure--"The procedure is quite simple, requires very few surgical tools, and can be performed in most any location," Redden explained. "Using a sling for induction (of anesthesia) and recovery certainly reduces the risk of injury during recovery (and cast changes)."
With lower limb amputations, if the coronary groove, digital cushion, and frog can be sutured to the existing tendon and skin, this "provides the stump with a tough pad," he said. This procedure allows frog and sometimes hoof wall tissue to grow over the end of the stump, which is much tougher and more able to withstand weight bearing on a prosthesis than normal skin.
If the amputation site is higher on the leg, Redden harvests a small "donation" of germinal frog tissue from a foot on the opposite end of the horse for implantation throughout the stump.
Post-Operative Care--Following the amputation, pins are placed through the cannon bone above the amputation site, and a cast is built around the pins for weight bearing. The stump is thus not loaded and better able to heal.
"A temporary prosthesis can be made in a typical shop using a variety of materials," he said. "The goal is simply to replace leg length and secure it to the limb so it doesn't twist or fall off." He also recommended that the opposite foot be protected to avoid contralateral limb laminitis. (For more information, see article #4243 online.)
Hock Joint Mechanics
"One of the most frequent sites of lameness is the hock joint," said Hilary Clayton, BVMS, PhD, MRCVS, Mary Anne McPhail Dressage Chair in Equine Sports Medicine at Michigan State University (MSU), when presenting "A New Look at the Hock Joint."
Normal Hock Function--Clayton presented the results of several MSU hock studies, beginning with a description of normal hock motion. The hock, she explained, is a very complex joint with several smaller joints between its many bones. Aside from the primary motions of flexion and extension when viewed from the side, "the distal tarsal joints are thought to undergo small amounts of movement during normal locomotion, and these movements may be important in the etiology of hock lameness, such as bone spavin," she said.
She also described the forces on the hock, its mechanical functions, and the structures that move it. She discussed normal motion patterns and variations between horses, as well as three-dimensional motion studies.
Hock-Lame Horses--Another MSU study evaluated the mechanical effects of synovitis of the distal hock joints, which could precede bone spavin. Clayton reported that horses with grade 1-2 hock lameness showed a decrease in hock flexion of about 2.5 degrees, which is about 20% of the total stance phase flexion. They also exhibited decreased forward sliding of the cannon bone relative to the tibia during the stance phase, which "might result in repetitive loading on a focal area of articular cartilage, which may lead to the development of osteoarthritis," she suggested.
She added that the horses "moved with less vertical motion in the gait, or a flatter gait. This is very important because horses become lame when the pain gets to a certain point. Before that, subclinical lameness may take the form of a deterioration in gait quality, so the flatter gait is the initial method of compensation."
Clayton also discussed a study presented at the 2002 American Association of Equine Practitioners convention on the effects of Corta-Flx, an equine joint supplement, on hock lameness. (For more on this study, see article #4050 online.)
Shoeing for the Hocks--"Shoeing methods that prevent the hoof sliding forward at impact may increase the longitudinal deceleration forces," Clayton suggested. "Transmission of these forces through the hock joint may increase sliding motion at the distal joints." (For more information, see article #4143 online.)
She also presented several studies on biomechanics of the lower limb. (For more information, see article #4105 online.)
Pat Parelli--Anvil Side Manner
"For seven years in a row, I've been voted the world's worst shoer," joked world-renowned clinician Pat Parelli to begin a discussion on "Anvil Side Manner."
"You guys showing up on the scene are often in the world's worst scenario," he said. "Let's say your first appointment is at 6 a.m. When you get there, what if the horse isn't even caught? Prior proper preparation (PPP) prevents p***-poor performance, but you haven't gotten any PPP from the owner. If you aren't part of the solution, you're part of the problem. It's the owner's responsibility to ensure that the time you spend shoeing a horse is the only time you spend on the horse."
With the audience's help, Parelli estimated about 45 minutes for shoeing the average, behaving horse. Much beyond that, he suggested billing for extra time. "Suggest to your client that you bill them for your time over one hour on each horse that's misbehaving," he said. "You might lose clients, but those were probably the ones you wanted to lose. But that won't happen if you're a wuss and keep shoeing horses for $100 that take two to three hours." Also, he noted that owners with well-behaved horses wouldn't get into this pricing issue.
"You never have time to do it right (train a horse to stand for shoeing), but you have the time to do it over and over (training the horse a few minutes at a time every six to eight weeks when shoeing)," he said. "A lot of people get sucked into bad situations because they didn't set them up right."
Horse Psychology--"Horses aren't horses, they're prey animals," he said, beginning the kind of horse psychology discussion for which he is well known. "We can't use predator psychology (humans are predators) to make prey behave. Punishment doesn't work for prey animals--that makes them act like super prey animals! Many trained horses put up with some of this stuff, but it's not instinctive.
"You have to be gentle without being a sissy, which is hard to teach." (For more information, see article #4250 online.)
Parelli--Shoeing Difficult Horses
"Usually you shoe horses that are against you, right?" asked Parelli in his second presentation. "You're on opposite teams. And when push comes to shove, the horse wins when it comes to shove."
Survival Instincts--"If he's afraid, don't try to dominate him, as this will panic him," Parelli said. "If he's being stubborn, not scared, then you need to dominate him."
Reiterating a theme from his earlier presentation, he listed the main behavioral problems with horses as being afraid, disrespectful, and/or full of oats. "Which kind of horse is it?" he asked. "If you know, you can work out a solution with the owner. If he's full of oats, ask to have him worked before you get there. Try never to put yourself into a situation where you could be the loser. It's all about preparation."
Scared Horses--"Think about horses from their perception and forget about yours," Parelli said. "When a horse acts like a prey animal, we cannot act like predators in any way, shape, or form," he continued. "A nervous horse has a lot of adrenaline going, and if it can get Grandma to pick up a car off her grandson, think what it can do to a scared horse," he laughed.
"The opposite of fear is curiosity," he explained. "Rather than walking up to a scared horse, if you can get him to follow you, you can change his perception. You'll be amazed at the difference that one little thing can make. It's better to work on this at the front end than at the back (when you and the horse are already frustrated)."
He then went on to discuss the next step--touching the scared horse. "You can touch most foals easiest on the hip," he said. "With mature horses it's the withers. Read the signs and let the horse tell you when you can go further. Approach and retreat, and you might have to work on areas other than the feet first. Something most people don't do is contact to make the horse feel good, like massaging."
"The real key is that you need to get your clients to do this stuff," he concluded. "They have a lot more interaction with the horse than you can once every six weeks." (For more information, see article #4251 online.)
Shoeing in the Frontal and Horizontal Planes
When evaluating horseshoeing, many people don't look at the hoof correctly, according to Hans Castelijns, DVM, a farrier based in Italy. "There are the sagittal, frontal, and horizontal planes," he said in his presentation "Shoeing in the Frontal and Horizontal Planes." "You can have conformational problems in all planes."
One of his first bits of advice was to be careful about drawing conclusions regarding how a domestic horse's hooves should be shaped based on information from wild horses. "Feral horses are not wild, just horses that escaped from humans that were once bred for a purpose, and conformation has much to do with breeds," he explained. "And you can't run a 1:48 mile with a feral horse. They are adapted for survival in the wild, not athletic pursuits."
If a young horse has hoof/leg conformation problems, Castelijns said you must act quickly. "The way they're raised has tremendous influence on their feet," he said. "Adapt shoeing and trimming as needed when they're young (less than a year old)."
Adult Horses--Castelijns first discussed angular and rotational deviations (ADs and RDs), noting that, "The first can best be evaluated by viewing the horse from the front or the back (in the frontal plane), the second by looking down the limb when standing close to the horse (in the horizontal plane). ADs and RDs are often associated and can occur at multiple sites (joints) in the same limb." These problems also affect stress on the joints and flight path of the limbs, he said.
Conformation Problems/Hoof Shape--The result of ADs and RDs, Castelijns stated, is usually atrophy of the side of the hoof opposite the deviation. This appears to be an adaptation to even out stresses on these poorly conformed limbs
Shoe Problem Limbs (Not Just Hooves)--Castelijns said that correction of these joints with shoeing isn't possible in adult horses, but noted that minimizing abnormal stress in the affected joints (and thus improving the likelihood of soundness) is possible.
"Trim and shoe the horse with conformational defects in the frontal and horizontal planes so that the joint spaces remain even," he said. "To obtain this, it's usually appropriate to recognize and respect hoof shape, even though in severe deviations this shape looks out of the ordinary. Horseshoes that bring lateromedial breakover closer to the hoof's center will diminish joint stress and should perhaps be used preventively."
"When holding an asymmetrical hoof, it is good practice to put it down and take the time to analyze the conformation of the limb it is attached to," he said. "Beware of the urge to always obtain nice, symmetrical, 'normal' feet, which might be more pleasant to behold, but which might not respond to the biomechanical needs of a horse affected with angular or rotational deviations." (For more information, see article #4252 online.)
Self-Adjusting Palmar Angles
"How do we use the palmar angle (the angle the wings of the coffin bone make with the ground) to influence the mechanics of the foot?" asked Redden in his presentation "How to Use Self-Adjusting Palmar Angles to Treat Heel Pain."
First, you have to define which palmar angle you're discussing--the one between the coffin bone and the ground surface of the foot, and/or the one between the coffin bone and the ground. On a barefoot horse, or one with a flat shoe, they'll be the same; however, with a wedge pad or other non-flat shoe, the angles could be very different.
Next, consider the mechanics already at work inside the hoof. The foot's equilibrium "is based on the fact that all structures of the support mechanism perform as a healthy, fully functional unit," he added. "When one member fails, the next one is challenged, and soon a cascading series of events is well on its way."
Treatment--"You want to be able to let the horse shift his weight away from the hot spot," he explained. "It's amazing how fast they can heal if you relieve the hot spots and increase perfusion (blood supply)." Modifying stresses starting with the bony column and the inner hoof environment--not just the outer hoof capsule--has yielded improvement in many tough cases, he said.
The palmar angle (with the ground) will be 3-5ï¿½ on normal, strong front feet, and the plantar angle (hind foot's palmar angle) should be 5-8ï¿½ on hind feet, he said. However, many equine athletes have heel compression and thus a decreased palmar angle. But what's often seen and what's healthy aren't necessarily the same thing, he added.
Redden's shoeing system for improving the heel environment allows a standing horse to adjust his hoof angle to a comfortable spot. If a horse is shod so breakover is moved back to directly beneath the center of articulation of the coffin joint (with a shoe that has a curved ground surface), he said that the horse can sleep standing up all day without moving and still provide a better healing environment. The little movements of balancing and conscious weight shifting shift the tendons and thus change the load on the inner structures, massaging the circulation within the foot that is necessary for healing and tissue growth.
"The venograms show clear evidence to support this concept; it's not just a theory," Redden said. "Instead of pushing the heel into place with a wedge, we're letting him pull his foot into place with the rock and roll shoe. It's 24-hour healing."
The bone angles with a tailored shoe might be the same as those with a wedge pad, but they are created by the horse using his tendons, not compressive force on the heels brought on by static shoes. This, along with the air space beneath the heels of the curved shoe, spares the blood vessels and digital cushion in this area and thus allows heel growth to improve.
He noted that this shoeing style is useful in horses with crushed heels, long-toe/low-heel conformation, heel pain, sole pain from internal bruising (such as crushing of the sole under P3), pedal osteitis, laminitis, toe cracks, thin soles, and quarter cracks. "You need film (X rays) before and after shoeing these horses; otherwise, you don't know what you've done," he cautioned. (For more information, see article #4245 online.)
The Owner's Perspective
Not forgetting the client in all this hoof care information, Redden had Deborah Mihaloff Kirshner, an Arabian racehorse breeder from Doswell, Va., discuss her experiences with severe foot problems in her racehorses. Her experiences with two top-quality fillies with foot problems, both of which were saved with Redden's concepts, led her to state, "I urge all of you as responsible owners and caretakers to open your minds and get another opinion. Tap into the resources offered to all of us today by professional people such as Dr. Redden."
Redden said after her presentation, "The message is that owners are real people. We're all guilty of forgetting the owner in all this. We might ask why anyone would want to pay to fix this horse, but the owner looks at him in a whole different way. When there is any, we have to offer hope--not a guarantee of results, but hope. This meeting is here to open eyes and minds, and offer challenges. There are ways to offer hope, and most clients really want to know them."
Every year, Redden brings several horses into the Galt House Hotel for an afternoon of shoeing demonstrations to wrap up the symposium. The demonstrations are professionally videotaped and televised in the nearby meeting room, thereby allowing all attendees to see what's going on without crowding around a horse. Anything can happen, from a simple balance correction to a deep digital flexor tenotomy and casting right there in the hotel.
Radiographs are a big part of the learning experience, as are the scheduled presentations by several different educators. This year, presentations included the following:
- Shoeing the Laminitic Horse With Heel Pain (Hans Castelijns, DVM, farrier);
- Super Team on a Lame Horse (Julie Grohs, DVM, Alaska Equine and Small Animal Hospital in Chugiak, Alaska; and John Arkley, Certified Journeyman Farrier);
- Performing Venograms (Rucker); and
- Manipulating the Palmar Angle (Redden).
All of the cutting-edge hoof information presented at this symposium is very helpful to the fledgling field of equine podiatry. Equally valuable is the open, helpful atmosphere in which everyone is learning and helping each other understand new concepts. Equine podiatry is vitally important to improving the soundness of our horses, and advances benefit us all.
CASE STUDY: MISPLACED NAIL ON A THOROUGHBRED MARE
"Who here has never stuck a horse (driven a nail into sensitive areas when shoeing)?" asked Redden. Very few out of the 550-plus attendees (mostly farriers) raised their hands, showing that the following problem could happen to anyone.
Julie Grohs, DVM, of the Alaska Equine and Small Animal Hospital in Chugiak, Alaska, presented a case study of complications following a misplaced nail in a Thoroughbred hunter/jumper mare. Initially the 7-year-old mare was in excellent physical condition with no history of lameness, but became sore the evening of a reset in spring of 2002 with commonly used, very wide-web shoes. The farrier returned that evening to reset the shoes and lower the nail holes.
One nail hole bled at this time, though this wasn't discovered until later. This missing fact led to misdirected initial veterinary treatment, and thus began a story filled with complications that is still going on. Sage initially suffered contamination of the inner structures of the left front hoof from the misplaced nail (requiring surgery to clean out the infection and damaged bone), but later developed laminitis in the right front because of the increased load. The right front hoof required aggressive treatment (inset), but is improving as well. The mare is now nearing fitness for light longeing. For the full story and photos, see article #4244 online.
MORE LAMINITIS SYMPOSIUM REPORTS: www.TheHorse.com/BGLS
About the Author
Christy West has a BS in Equine Science from the University of Kentucky, and an MS in Agricultural Journalism from the University of Wisconsin-Madison.
POLL: Tack Shopping Choices