Proceedings of the 57th Annual Convention of the American Association of Equine Practitioners - AAEP -

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1 Proceedings of the 57th Annual Convention of the American Association of Equine Practitioners - AAEP - November 18-22, 2011 San Antonio, Texas, USA Next Meeting : Dec. 1-5, Anaheim, CA, USA Reprinted in the IVIS website with the permission of the AAEP

2 How to Use Foot Casts to Manage Horses With Laminitis and Distal Phalanx Displacement Secondary to Systemic Disease Raul J. Bras, DVM Foot casts have been recommended for horses with distal phalanx displacement. 1 Stabilization of the hoof capsule and more uniform weight distribution by the cast may prevent additional damage. However, the prognosis for rehabilitating a horse with distal phalanx displacement remains poor after a palpable ledge or separation is evident around the entire coronary band. Author s address: Rood and Riddle Equine Hospital, PO Box 12070, Lexington, KY ; rbras@roodandriddle.com AAEP. 1. Introduction Despite significant research and recent findings over the past decade, a complete understanding of laminitis and its complex pathophysiologic processes remains unknown. Although preventative measurements and strategies to manage this devastating disease remain largely empirical and anecdotal, with little information from evidence-based medicine, recent technological advances offer some promise for the effective treatment and/or rehabilitation of the laminitic horse. Laminitis may result in failure of the attachment between the distal phalanx and the inner hoof wall, causing unrelenting pain and characteristic lameness. Distal displacement of the distal phalanx is a well-recognized and devastating complication that may develop. The mechanical collapse of the distal phalanx can occur at any point around the lamellar attachment of the bone to the hoof wall. Distal phalanx displacement occurs in three different patterns: dorsal rotation, symmetrical distal displacement, and uniaxial distal displacement. 2 During dorsal rotation, the distal phalanx separates from the dorsal hoof capsule and rotates about the distal interphalangeal joint (rotation). Symmetrical distal displacement or sinking occurs when the lamellae mechanically collapse evenly around the entire attachment to the hoof wall and the third phalanx displaces distally into the hoof capsule. Uniaxial distal displacement occurs when the lamellae mechanically collapse on only the medial or lateral aspect of the hoof capsule. Although each type of displacement may occur independently, a combination of the three types of displacement is often exhibited in many horses. 2 The region of the foot under the greatest load is usually the first area to become compromised. Most horses at stance phase load the medial toe region on the front feet and lateral toe on the hind feet. Therefore, horses suffering from laminitis on the forelimb usually rotate and sink medially, whereas in the hindlimb, they usually sink laterally and rotate. 3 NOTES AAEP PROCEEDINGS Vol

3 lanx displacement secondary to systemic disease. Foot casts extending from the hoof to just distal to the metacarpo/tarsophalangeal joint are believed to stabilize the entire foot, decreasing independent movement of the hoof capsule and bony column, with the goal of reducing shearing and twisting of the lamellar interface. Stabilization of the hoof capsule and more uniform weight distribution by the cast may prevent additional damage by reducing the likelihood that small areas of lamellar damage may propagate to adjacent areas as the hoof capsule independently moves, creating more diffuse areas of separation. The foot cast should include axial support and ease of breakover in all directions. 1 Fig. 1. The soft tissue immediately proximal to the coronary band becomes depressed (ledgy) inside the margin of the hoof capsule when the distal phalanx displaces within the hoof. The coronary indentation or depression can be palpated, and it should be assessed frequently in horses at risk for laminitis. In general, the specific objectives to limit displacement of the distal phalanx should include (1) reducing effective body weight, (2) recruiting all or parts of the sole and frog to bear and share weight, (3) redistributing weight-bearing from the most stressed portion of the wall to the least stressed portion of the wall, and (4) decreasing the moments around the distal interphalangeal joint. 4,5 The objective of this paper is to describe the use of foot casts for horses with laminitis and distal pha- 2. Materials and Methods Medical records from Rood and Riddle Equine Hospital from 2005 to 2011 were reviewed. Horses were selected for inclusion if they had a diagnosis of laminitis secondary to systemic illness and were treated with foot casts. Information recorded included age, sex, breed, use, primary systemic disease, feet affected with laminitis, treatment instituted before foot cast application, grade of lameness immediately before casting was performed, grade of lameness immediately after casting, grade of lameness when casts were removed, time from admission until foot cast application, time from onset of clinical signs until deep digital flexor tenotomy was performed, hospitalization status, and outcome. All of the horses were closely monitored daily for comfort level or any signs of lameness. Frequent examinations of the foot, including daily palpation of the coronary band and digital pulses, were evalu- Fig. 2. (A) Contrast medium being injected using a 21-gauge 0.75-in butterfly catheter a into the lateral digital vein at the level of the pastern. A tourniquet has been placed at the level of the proximal sesamoid bones. (B) Lateral-medial view radiographic contrast study (venogram) with evidence of perfusion deficits on the coronary plexus (arrowhead), parietal plexus, circumflex (long arrow), and solar plexus (short arrow). (C) Dorso-palmar view radiographic contrast study (venogram) with evidence of perfusion deficits on the medial and lateral coronary plexus (arrows) Vol. 57 AAEP PROCEEDINGS

4 Fig. 3. Coronary band grooving is performed by making a horizontal groove in the proximal hoof wall about 0.5-in below the hairline (arrow). The groove should extend the full length of the compromised region. ated to detect subtle signs of structural failure (Fig. 1). Standing lateral-medial and dorso-palmar/ plantar radiographs of the feet were taken on horses with clinical signs of laminitis for additional evaluation of the distal phalanx displacement. The initial type of distal phalanx displacement was determined by coronary band palpation and radiography before the feet were casted. Digital venography of the affected feet was performed on 29 horses to determine the presence or absence of perfusion deficits. After sterile preparation of the area, ml iodinated contrast were injected using a 21-gauge 0.75-in butterfly catheter a into the medial or lateral digital vein at the level of the pastern, with a tourniquet applied at the level of the proximal sesamoid bones. A three-way stopcock was used at the junction of the butterfly catheter and the syringe to prevent leakage of the contrast material after the injection was completed. Immediately after injection, standing lateral-medial and dorso-palmar/plantar radiographic images were obtained (Fig. 2). Foot casts were applied on horses with clinical signs of acute laminitis and evidence of displacement of the distal phalanx (sinking) based on radiographic evidence or digital palpation of a ledge at the coronary band. Before placement of the cast, the foot was trimmed flat, and the distal border of the hoof wall was heavily rolled or beveled. Subcoronary band grooving was performed in areas that showed signs of sinking. Sub-coronary band grooving was performed by making a groove in the proximal hoof wall about 0.5-in below the hairline using the edge of the rasp (Fig. 3). The groove extended through the stratum medium, and therefore, the pliable stratum internum was exposed and extended along the full length of the compromised region. Elastomer sole support material b was molded to the solar surface. A 0.5-in-thick piece of felt was applied on the ground surface of the foot to prevent unnecessary sole pressure from the cast, and taped in place with adhesive wrapping material c (Fig. 4). The foot was cast using a stockinette, cast padding d, and fiberglass casting tape e (Fig. 5). A piece of felt was used around the pastern region to prevent cast sores, and a total of two rolls of 4-in cast material and one roll of 3-in cast material was used. The cast extended from the sole to just distal to the metacarpo/tarsophalangeal joint (Fig. 6). The foot was placed on a firm flat surface until the cast cured. Five ounces methylmethacrylate f were used to create a dome-like contour on the ground surface of the cast (Fig. 7). The apex of the dome was located near the center of the distal interphalangeal joint (or at the widest part of the sole). This method allows the foot to breakover in all directions and loads the Fig. 4. Elastomer sole support material b (arrow) is molded to the sole surface and taped with a felt pad (arrowhead) in place with adhesive wrapping material c. AAEP PROCEEDINGS Vol

5 Fig. 5. (A) The foot is prepared using a stockinette (long arrow) and taped felt (arrowhead). (B) Procell cast padding d (arrow) is applied over the stockinette and felt to prevent cast sores. axial regions of the foot while unloading the hoof wall perimeter. 1 The foot cast was left in place and changed every 30 days. After the casts were removed, the coronary bands were evaluated by digital palpation, and radiographs were taken for additional information. Final cast removal was performed when no additional distal phalanx displacement was evident. After the casts were removed and no evidence of complications, such as additional distal displacement, was evident, boots or therapeutic shoes for Fig. 6. The foot is cast using fiberglass casting tape e, and it extends up to the level just distal to the metacarpophalangeal joint. Fig. 7. Acrylic f is used to create a dome-like contour on the ground surface of the cast, allowing the foot to breakover in all directions Vol. 57 AAEP PROCEEDINGS

6 chronic laminitis were applied for support and protection. Horses were allowed to go to a small restricted area (i.e., square pen) for a short period of time if no or minimal lameness was evident without the use of anti-inflammatory drugs, and area and time of turn out gradually increased if continued to improve. Transection of the deep digital flexor tendon was performed on horses that developed severe rotational displacement during or after treatment with the phalangeal casts. Realignment shoeing, also known as derotation shoeing, was applied in these cases to allow for immediate realignment of the coffin bone relative to the ground surface, which was described by Morrison. 6 Long-term follow-up of at least 2 yr on all the horses was done by routine reevaluations, direct contact with referring veterinarians, and phone conversations with the current owners of the surviving horses. The outcome was considered successful if the horses became pasture-sound after treatment. 3. Results Forty-three horses met the criteria for inclusion in the study (Table 1). Most of the horses (34/43) were admitted to the hospital with a history of systemic disease. Twenty-one horses presented with colitis, but horses also presented with metritis because of post-foaling complications (dystocia or retained placenta; 8/34), pneumonia (5/34), acute renal failure (3/34), or combinations of disease. After diagnosis of the inciting cause, treatment was initiated accordingly. Nine horses diagnosed with metritis (abortion or retained placenta) were treated at the farm without hospital admission. Twenty-six horses were diagnosed with laminitis in the forelimbs only. Seventeen horses were diagnosed with laminitis in both fore- and hindlimbs. Eighteen horses were in the acute phase with no evidence of radiographic displacement, and twentyfive horses were diagnosed in the early chronic phase with evidence of radiographic displacement. Based on a combination of digital palpation and radiographs, 22 horses were determined to have primarily symmetrical distal displacement, and 21 horses were determined to have primarily asymmetrical displacement. Horses with asymmetrical displacement were determined to have primarily medial distal displacement in the front feet, with four horses having lateral displacement in the hind feet as well (Table 2). Venograms were not analyzed quantitatively; however, there were some horses with poor perfusion patterns that survived, whereas others with apparently good perfusion patterns were eventually euthanized. Foot support including boots i with pads were applied to 53% (23/43) of the horses, and cryotherapy was performed on 28% (12/43) of the cases for at least 3 days after presentation (Fig. 8). All four feet were casted on 17 (40%) horses, and 26 (60%) horses had the front feet casted with boots with sole support applied to the hind feet. Twenty-one horses required a total of one set of casts, sixteen horses required two sets, five horses required three sets, and one horse required four sets. Lameness was graded using the obel grading system before and after casting was determined. Three horses had an obel grade two, twenty-two horses had an obel grade three, and eighteen horses had an obel grade 4 before casting. Thirty-eight horses improved at least one obel grade immediately after casting, whereas five horses remained at the same obel grade level (Table 2). Horses that improved immediately after casting continued to improve during the time wearing the casts until minimal or no lameness was evident. A total of 23 horses developed marked rotation (dorsal distal displacement while cast or after casting). Thirteen of these horses required deep digital flexor tenotomy; nine horses survived, and four horses were euthanized. Six of thirteen horses were initially symmetrical distal phalanx displacement, and seven horses were asymmetrical distal phalanx displacement (six horses, medially; one horse, laterally). Horse 1 had bilateral tenotomies on the hindlimbs, and horse 8 required a second tenotomy at the pastern region because of additional dorsal displacement 3 mo later after the first tenotomy. Both of these horses survived. If some degree of distal displacement remained at this stage (unstable), a foot cast was applied over the derotational shoe, which was required on 46% (6/13) of the horses. Tenotomies were performed on horses that had evidence of severe dorsal displacement after the casts were removed, and these horses were considered to be in the stable chronic stage of the disease. The overall survival rate of horses with distal phalanx displacement (sinkers) treated with foot casts for laminitis secondary to systemic disease was 47% (20/43); 38% (8/21) of horses had symmetrical distal displacement, 57% (12/21) of horses had asymmetrical displacement survived (one horse presented with a combination of patterns), and 53% (23/43) of horses were humanely euthanized, because they showed no improvement or complications developed after treatment. Of the horses that survived, 60% (12/20) initially had asymmetrical distal phalanx displacement (all medial except for one horse that also had lateral displacement in the hind feet), and 40% (8/20) initially had symmetrical distal displacement. Of the horses that were euthanized, 61% (14/23) initially had symmetrical distal phalanx displacement, and 39% (9/23) initially had medial distal phalanx displacement (three horses had lateral distal displacement in the hindlimbs). The majority of the horses were broodmares (32/43), and these survivors returned to successful broodmare careers. AAEP PROCEEDINGS Vol

7 Table 1. Clinical Description: 43 Horses With Laminitis Secondary to Systemic Disease Horse Breed Age (Yr) Gender Previous Use Before Laminitis Primary Systemic Disease Diagnosed Feet Affected With Laminitis Time From Admission Until Foot Cast Application Total Number of Casts Treatment Instituted Before Cast Application Time From Admission Until DDF Tenotomy Admission Outcome 1 Morgan Adult Gelding Show ARF, enteritis All four 5 days F/H 3 Boots 2 mo, L/RH Hospital Survived 2 TB 20 Mare Broodmare Colitis L/RF 11 days L/RF 4 Boots 3 mo, RF; Hospital Survived 4 mo, LF 3 Gypsy 14 Mare Show Metritis L/RF 7 days L/RF 2 Boots 3 mo, L/RF Hospital Survived 4 QH 11 Gelding Show Colitis L/RF 40 days 1 Ultimates, 8 days Hospital Survived 5 TB Adult Mare Broodmare Metritis L/RF 58 days 1 Boots, 8 days 3 mo, L/RF Hospital Survived 6 Tennessee Walker Adult Gelding Show Colitis L/RF 15 days 2 Ultimates, 2 days 1 mo Farm Survived 7 TB Adult Mare Broodmare Pneumonia, metritis L/RF 33 days 2 Ice and boots Hospital Survived 8 TB 15 Mare Broodmare Metritis L/RF 10 days 2 Boots 2 mo, L/RF; 5 mo, Farm Survived 2nd DDF tendon RF 9 Morgan 8 Gelding Show Colitis All four L/RF, 1 day; L/RH, 2 days 2 N/A Hospital Survived 10 TB 4 Mare Broodmare Colitis All four 2 days 1 Ice Hospital Survived 11 TB 17 Mare Broodmare Metritis, ARF L/RF 16 days 1 Ice Hospital Survived 12 TB 7 Mare Broodmare Colitis L/RF 2 days 3 Boots Hospital Survived 13 TB 15 Mare Broodmare Metritis L/RF 5 days 2 Boots 3 mo, LF Farm Survived 14 TB 3 Mare Racing Colitis All four 1 day 1 Ice Hospital Survived 15 Morgan 3 Stallion Show Colitis All four 4 days 1 N/A Hospital Survived 16 TB 13 Mare Broodmare Metritis L/RF 3 days 2 N/A Farm Survived 17 TB 17 Mare Broodmare Metritis L/RF 2 days 1 Boots Farm Survived 18 TB 6 Mare Broodmare Metritis All four 3 days 2 N/A 1 mo, LF Farm Survived 19 TB Adult Mare Broodmare Metritis L/RF 8 days 1 Boots Farm Survived 20 TB 15 Mare Broodmare Colitis All four 3 days 1 Boots 6 mo, LF Hospital Survived 21 QH 10 Mare Broodmare Colitis L/RF 13 days 1 Ice and boots 1 mo, L/RF Hospital Euthanized 22 TB 17 Mare Broodmare Colitis L/RF 1 N/A Hospital Euthanized 23 TB 7 Mare Broodmare Pleuroneumonia L/RF 12 days 1 N/A Hospital Euthanized 24 TB 8 Mare Broodmare Colitis, pneumonia All four L/RF, 4 days; L/RH, 5 days 1 Ice and boots Hospital Euthanized 25 QH 8 Gelding Show Pneumonia All four L/RF, 2 days; L/RH, 4 days 1 Boots 2 days, L/RF Hospital Euthanized 26 TB 26 Mare Broodmare Metritis L/RF 6 days 2 N/A Hospital Euthanized 27 TB Adult Mare Broodmare Metritis All four 1 day 3 N/A 2 mo, RH Hospital Euthanized 28 QH 14 Mare Show Colitis L/RF 2 days 1 Boots Hospital Euthanized 29 Arabian 11 Stallion Show Colitis/pneumonia L/RF 10 days 2 N/A Hospital Euthanized 30 TB 6 Mare Broodmare ARF, Colitis/ L/RF 15 days 1 N/A Hospital Euthanized pneumonia 31 TB 15 Mare Broodmare Metritis All four 1 day 1 N/A Hospital Euthanized 32 TB Adult Stallion Broodmare Metritis All four 3 days 2 Ice Hospital Euthanized 33 TB 7 Mare Broodmare Colitis All four 4 days 2 Boots Hospital Euthanized 34 TB 5 Mare Racing Colitis L/RF 7 days L/RF 1 Boots and ultimates Hospital Euthanized 35 TB 6 Mare Broodmare Colitis All four 1 day 3 N/A Hospital Euthanized 36 TB 9 Mare Broodmare Peritonitis All four 2 days 3 Ice and boots Hospital Euthanized 37 TB 4 Stallion Racing Post-throat surgery All four 3 days 1 Boots Hospital Euthanized 38 TB 22 Mare Broodmare Metritis L/RF 10 days 2 Ice and boots Hospital Euthanized 39 TB 18 Mare Broodmare Metritis L/RF 38 days 2 N/A 1 mo, L/RF Farm Euthanized 40 TB 16 Mare Broodmare Metritis L/RF 3 days 2 Boots Farm Euthanized 41 TB 3 Stallion Racing Colitis L/RF 2 days 2 Ice Hospital Euthanized 42 Paint 4 Gelding Show Colitis L/RF 3 days 1 Ice and boots Hospital Euthanized 43 QH 8 Mare Show Colitis All four 7 days 1 Ice and boots Hospital Euthanized DDF, deep digital flexor; ARF, acute renal failure; Boots, Soft Ride g boots with pads for sole support; Ultimates, wedged cuff shoe with sole support from Nanric h ; N/A, foot casts were applied within 1 day of presentation Vol. 57 AAEP PROCEEDINGS

8 Table 2. Clinical Description of the Type of Distal Phalanx Displacement and Grade of Lameness Horse Venograms Type of Distal Phalanx Displacement Obel Grade Before Casting Obel Grade After Casting 1 Yes Medial L/RF, lateral L/RH Yes Symmetrical No Symmetrical Yes Medial Yes Medial Yes Symmetrical No Medial Yes Medial Yes Symmetrical No Symmetrical No Medial Yes Medial Yes Medial No Medial Yes Medial Yes Medial Yes Symmetrical Yes Medial Yes Symmetrical Yes Symmetrical Yes Symmetrical Yes Symmetrical Yes Symmetrical Yes Symmetrical Yes Medial No Symmetrical No Symmetrical Yes Symmetrical No Symmetrical No Symmetrical No Symmetrical No Medial Yes Medial L/RF symmetrical Yes Medial Yes Medial Yes Medial No Symmetrical No Symmetrical Yes Medial Yes Medial Yes Symmetrical No Medial Yes Medial Discussion Distal displacement of the distal phalanx has been well-described. 2 The early diagnosis of distal displacement requires experience and regular examination. As previously documented by Baxter, 10 distal displacement may be clinically apparent before it is visible radiographically, which emphasizes the importance of repeated clinical examination. Techniques of applying phalangeal casts similar to those casts used by the author have been described, but this paper represents a novel use for them. 7 9 Foot cast application was decided on clinical signs of laminitis such as lameness, elevated digital pulses, digital palpation of a ledge over the coronary band, and radiographic evidence of distal phalanx displacement (sinking) secondary to systemic illness. Lameness at the time of casting varied depending on the degree or severity of the laminitis. In most of the cases, the lameness grade improved on a daily basis if not immediately after casting. One of the complications encountered with foot casts was cast sores around the pastern region that caused lameness, although these sores were considered minor if appropriate protection was applied before casting. The same foot cast application technique with the center of the dome on the ground surface was applied on all of the cases instead of trying to adjust the position of the dome to the distal phalanx with different types of distal displacements, because fre- AAEP PROCEEDINGS Vol

9 Fig. 8. (A) Cryotherapy in a horse suffering from proximal enteritis using a surcingle and bungee cords to hold the ice bags in place. (B) Boots i with pads (C) for sole support. quently, it is a combination. In the author s experience, adjusting the center of the dome on the ground surface of the casts in horses with acute and early chronic laminitis has not proven effective. After distal displacement was considered stable and casts were removed, therapeutic shoes with mechanics were adjusted depending on the type of displacement. The management of distal phalanx displacement with foot cast for laminitis secondary to systemic illness can be a technique used to stabilize the hoof capsule and prevent additional damage. The results of this technique are comparable with or better than those results previously reported for horses with distal displacement. 10,11 This technique offers some promise to the effective treatment or rehabilitation process of the laminitic horse. The technique used presents a potentially important aspect in the management of horses with acute and/or early chronic laminitis. Other casting techniques have been used for laminitis foot care and the chronic laminitis horses. 7 A half-limb cast with an open sole has been used in horses that were not responsive to conventional treatment and were affected with subsolar abscesses. A plaster cast of the hoof only was described and was aimed at diminishing laminar interface tension in the dorsal aspect of the hoof because of the raised heels, which reduces the deep digital flexor tendon pull. 8 However, raising the heels in a horse with distal displacement (sinking) is controversial, because there are concerns that it will promote or cause additional distal displacement. The application of a fiberglass foot cast with compliant impression material against the sole was previously described and used for cases with chronic laminitis that had poor quality and poor integrity hoof wall that was continually suffering from bruising of the feet. 9 Only one roll of 3- or 4-in cast material was applied to the foot. No mechanics on the ground surface of the cast were used on the three previously described techniques to facilitate the breakover in all directions. Venograms performed revealed different degrees of perfusion deficits depending on the individual case and the severity of the distal phalanx displacement. Venograms are helpful in determining whether a horse is developing distal displacement or when palpation of the coronary band is questionable based on the pattern of perfusion deficits such as compromised areas at the coronary and solar plexus in the horses with symmetrical displacement. However, horses with moderate to severe perfusion deficits could respond positively to treatments and start to reperfuse again, whereas other horses with mild perfusion deficits continued to displace and deteriorate with additional compromised perfusion deficits. Therefore, venograms should be interpreted in conjunction with a complete assessment of each individual case and the corresponding clinical and other diagnostic findings. The tenotomies were not performed in horses with dorsal displacement (rotation) until they were considered to be in the stable chronic stage of the disease, because the technique is potentially deleterious in horses that have had distal displacement and are unstable. This use is because a tenotomy causes the weight to be transferred to the caudal aspect of the foot (quarters and heels), which may make the horse prone to sink even more, leading to shearing or separating the coronary band from the hoof capsule Vol. 57 AAEP PROCEEDINGS

10 The most likely reason behind the effectiveness of the foot casts application described in this paper is the stabilization of the hoof capsule and support of the foot. This stabilization and support reduces movement between the hoof capsule and the bony column, and therefore, it acts more as a whole unit in hopes of decreasing the shearing forces in the laminar interface during twisting and turning, preventing additional damage. Reducing the stress on the lamellae would decrease the pain associated with the disease and enhance the return to stability of the hoof/distal phalanx interface. References and Footnotes 1. Morrison S. Foot management. Clin Tech Equine Pract 2004;3: Parks AH. Patterns of displacement of the distal phalanx and its sequel, in Proceedings. 46th Annual Beva Congress 2007; Morrison S. Rehabilitating the laminitic foot (Part I & II), in Proceedings. New Zealand Equine Veterinary Association Meeting 2006; Parks AH. Prevent and/or manage distal phalanx displacement in the acute stages of laminitis, in Proceedings. 46th Annual Beva Congress 2007; Baxter GM, Morrison S. Complications of unilateral weight bearing. Vet Clin North Am [Equine Pract] 2008;24: Morrison S. Long-term prognosis using deep digital flexor tenotomy and realignment shoeing for treatment of chronic laminitis. J Equine Vet Sci 2011;31: Belknap JK, Gomez J. How to use an open sole cast in cases of laminitis, in Proceedings. Am Assoc Equine Prac 2008;54: Castelijns HH. How to apply a (plaster) cast in cases of acute laminitis, in Proceedings. Am Assoc Equine Prac 2008;54: Hunt RJ. Equine laminits: practical clinical considerations, in Proceedings. Am Assoc Equine Prac 2008;54: Baxter GM. Equine laminitis caused by distal displacement of the distal phalanx. J Am Vet Med Assoc 1986;189: Cripps PJ, Eustace RA. Factors involved in the prognosis of equine laminitis in the UK. Equine Vet J 1999;31: a Terumo, Elkton, MD b Advance Cushion Support, Nanric, Lawrenceburg, KY c Vetrap, 3M, St. Paul, MN d Gore Procel, Newark, DE e Scotchcast, 3M, St. Paul, MN f Equilox Adhesive System, Pine Island, MN g Boots, Soft Ride, Bacliff, TX h Ultimates, Nanric, Nanric, Lawrenceburg, KY i Soft-Ride Gel Equine Comfort Boot, Bacliff, TX AAEP PROCEEDINGS Vol