Wall Ablation for Severe Laminitis

"Laminitis remains one of the deadliest syndromes facing your athlete, companion, or brood stock," saids Ric Redden, DVM, host of the 16th annual Bluegrass Laminitis Symposium and founder of the International Equine Podiatry Center in Versailles, Ky. "When not fatal it can be a crippling disease; fortunately, progress in the field of podiatry is changing the fate of horses with this feared and often misunderstood syndrome."

"Laminitis is inflammation of the laminae; the integrity and direction of the inflammation results in a large range of damage," he continues. "Significant loss of the intricate attachment of laminae, bone, and hoof wall precipitates displacement of the coffin bone, which occurs in three planes--rotation around the axis of the coffin joint, swelling of the laminae that pushes the bone away from the wall toward the heel, and vertical displacement best described as sinking. Rotation is most commonly found and ranges from very minimal to penetration of the sole by the toe of the coffin bone. These cases are quite easy to predict and mange regardless of the degree of rotation. Mild to moderate swelling often is successfully managed and doesn't necessarily have to reach crippling levels. Severe swelling though, 6-10 millimeters, often tips the scale and sends the bone in a vertical plunge, many times within hours of onset. This classic high-scale sinker virtually loses the vital blood supply due to the tourniquet effect of the hoof capsule."

"It's only a sinker when the hoof is on it--the hoof on a sinker can shut you down and 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."

While this approach seems too severe for some on first glance, Redden has had success with it in several high-scale cases. 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.

"Most veterinarians and farriers see less than six cases a year, and many never see a high-scale case," he noted. "The low- to mid-scale cases fortunately make up the majority of cases across the board. These cases are responsive to a multitude of mechanical devices (and) offer a false sense of security to those responsible for treatment. When no effort is made to clearly define the degree of damage, disaster strikes when the higher-scale cases are treated in the same manner."


1-250 Grade I to IV lame, no rotation or sinking Very good for full recovery; recovery time 4-6 weeks minimum, maximum one year
250-500 Grade I to IV lame, up to 5 degrees rotation Good for full recovery; 6-8 months minimum, up to one year
500-750 Grade I to IV lame, 5-10 degree rotation Survival chances good; fair for riding soundness; eight months to one year minimum
750-1,000 Grade I to IV lame, most grade IV; many are down, 10-plus degrees rotation, all penetrated; 1 cm sinking Fair to guarded for salvage; years in recovering

So what exactly is a high-scale case? See the chart at right for Redden's laminitis severity scale. He described an example of a high-scale case that he sees during foaling season as a broodmare which has recently had a very difficult delivery, often because of a very large or malpositioned foal. When one of these mares comes to him, he said, they have been heavily stressed and have acute laminitis within hours of delivery.

"Most cases are very painful, grade 5/5 lame (non-weight-bearing), glued to the ground in front and treading water with the hind feet, which spells big trouble with this history," he described. "Placing her in Modified Ultimates (specially designed shoes) or in Styrofoam (both designed to decrease stress on the toe) doesn't alter the clinical picture as one normally finds with the lower-scale cases. Radiographic damage may be seen only as laminar swelling, which can be up to 25 mm and may be missed by looking only for rotation. Most cases will show very distinct thickening of the laminae within hours of a significant bout of laminitis. Very disciplined, methodical, repeatable soft tissue films are necessary to see these early changes. Rotation remains a popular radiographic sign, but be keenly attuned to what is happening at the horn-laminar (H-L) zone (space between the front face of the coffin bone and the inner hoof wall) as it is by far the most useful information. Films made only a few hours later (on a high-scale case) can clearly show an increase in the H-L zone, decrease in sole depth, and increase in the CE (coronary band-extensor process measurement).

"You have got to get that Day 1 film," he urged. "You need that baseline so badly. 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. And the venogram will show you if something's cooking in there."


"A venogram (a radiographic procedure for visualizing blood flow in the foot; for more info on these, see article #4076) is the only way that I can accurately assess the degree of damage at this or any other stage," Redden stated. "I strongly advise veterinarians to perfect the technique on normal horses before attempting a severely laminitic case. Film interpretation must be relative to what is normal. A large range of normal exists as well as a large range of pathology, making life or death decisions based on little or no experience high-risk ones that often spell disaster.

"The venograms on most of the mares previously described will have stark loss of contrast along the anterior (front) face of P3 (the coffin bone), stark loss along the circumflex zone (just beneath the toe of the coffin bone), and often little or no contrast in the terminal arch."

Redden again asked attendees to hone their venogram technique on normal horses in order to improve their practice of the procedure and learn to recognize artifacts (misleading information in the films caused by poor technique). "Avoid misinterpreting the artifacts found with poor technique, as it may decide the fate of your patient," he said. "Also, if you blow veins, you might do a lot of damage when the hoof is already compromised (a normal foot handles this fine, but a damaged foot needs all the blood flow it can get). Learn this technique-sensitive procedure before working on a client's horse. You have to do your homework--this is very serious business, highly detailed, and time is of the essence.

"When the venogram describes a foot that is 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," he stated.

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. The edema (fluid swelling) and pressure between the coffin bone and the inner hoof wall common to acute cases causes severe damage within hours to days. 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 and the bone is rapidly dying. "The wall becomes a tourniquet in these cases," Redden said. "When you have 10 mm of sinking and 5-10 mm of swelling in a rigid hoof capsule, it makes a pretty good tourniquet.

"I have 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 a reasonable degree of success," he continued. "Venograms during all stages of the syndrome on a large number of cases have convinced me that it was the degree of vascular (blood vessel) damage, the speed that it occurred, and the time lapse or chronicity of the compressive forces (that determined success or failure) with the high scale cases."

He noted that when the wall is removed he likes to see the laminae perfuse immediately. If the laminae don't fill and bleed profusely in 30 seconds, the horse might have too much damage to survive. "Some of these horses have white inner walls from the compression (which forces all the blood out), and they don't bleed at all at first. You strip a healthy foot like this, they'll need a transfusion."

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. Of the others, one did not respond well to the procedure due to irreversible damage, one responded but developed sepsis (infection) in the coffin joint, and one did well until developing renal (kidney) that resulted in euthanasia.

Following full wall ablation, he applies a walking cast built around transcortical pins (inserted through the cannon bone) for weight bearing. He has performed the entire procedure standing and under general anesthesia, and noted benefits and downsides to both. He described these, along with the procedures, in great detail to the symposium attendees. One of his cautions was that difficult horses which always fight you don't often make it. "They defeat themselves," he commented.


"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 severely damaged cases were actually treated much too late--they showed a good initial response and began to cornify the laminae, but plateaued out too early to reach a favorable response, he said. "Pins are normally pulled at three to seven weeks, once microfractures appear radiographically. Another cast is applied for three to four weeks, and occasionally new pins are put in depending on the degree of recovery. They are not as happy with the pins out, and are expected to be down more over the next two to three weeks, therefore bed (the stall) very heavily. After six to eight weeks, I may decide to cut the deep flexor tendon depending on the palmar angles; most have had a tenotomy at this stage.

"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; all have had some degree of bone damage, but all those surviving continue to show a steady response. They have good body condition and attitude. 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."

"There's not a foundered horse in the world that needs killing immediately," he stated. "It's a big decision to end a horse's life. I've seen colleagues kill horses because they didn't know what to do with them. Don't make hasty decisions." He concluded by telling attendees that they are more than welcome to call him for help with difficult cases.

About the Author

Christy M. West

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.

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