Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
MacLeay JM, Kohn CW.Quantitative urine cultures were performed on 11 male and 11 female healthy adult horses. Urine was collected by free catch and catheterization using standard methods. Results showed that all samples collected by free catch contained less than 20,000 colony-forming units (CFU)/mL. All samples collected by catheterization contained 500 CFU/mL or less. A significant difference was found between collection methods (P < .005), with catheterization having less contamination. In samples collected by free catch, females had significantly greater contamination than did males (P < .03). Predominant bac...
Foreman JH.Exhaustion occurs in most equestrian sports, but it is more frequent in events that require sustained endurance work such as endurance racing, three-day eventing, trial riding, and hunting. Exhaustion is also more likely when an unfit, unacclimatized, or unsound horse is exercised. Mechanisms that contribute to exhaustion include heat retention, fluid and electrolyte loss, acid-base imbalance, and intramuscular glycogen depletion. Clinical signs include elevated temperature, pulse, and respiratory rate; depression; anorexia; unwillingness to continue to exercise; dehydration; weakness; stiffne...
Sosa León LA.One of the most common consequences of prolonged exercise is fluid and electrolyte depletion. Fluid and electrolyte losses during exercise may limit the horse's performance and, in extreme cases, jeopardize its health. To avoid or treat the deleterious effects of dehydration, fluid and electrolyte supplementation is essential. This article provides recommendations for fluid and electrolyte supplementation for horses involved in endurance-related events.
Sternberg S.Swab samples were collected from the oral cavity of 174 horses in 10 farms and cultured selectively for Actinobacillus equuli. A. equuli could be isolated from 37% of all samples, varying between 12 and 88% in the different farms. Eight horses were sampled repeatedly for several days, with a variation in isolation frequency between 50 and 88%. Isolates were compared by restriction enzyme digestion and Pulsed-Field Gel Electrophoresis. A high degree of strain variability was found within each horse population as well as some variability over time between strains isolated from the same horse.
Belshan M, Harris ME, Shoemaker AE, Hope TJ, Carpenter S.Sequence analysis identified significant variation in the second exon of equine infectious anemia virus (EIAV) rev. Functional analysis indicated that limited amino acid variation in Rev significantly altered the export activity of the protein but did not affect Rev-dependent alternative splicing. EIAV Rev can mediate export through two independent cis-acting Rev-responsive elements (RREs), and differences among Rev variants were more pronounced when both RREs were present. Variation in Rev may be an important mechanism for regulation of virus replication in vivo and may contribute to changes ...
Okumura M, Asano M, Tagami M, Tsukiyama K, Fujinaga T.Serum concentrations of copper (Cu), zinc (Zn), manganese (Mn), calcium (Ca) and inorganic phosphorus (P), as well as antigenic ceruloplasmin (Cp) and oxidase activity as a functional index for copper metabolism, were measured in 10 foals (5 males and 5 females) and their dams. Samples were harvested from the foals within 1 wk after birth and monthly from 1 to 17 mo of age. Samples were collected from their dams in the perinatal period (monthly from 2 mo before delivery to 5 mo postpartum). Serum oxidase activity, antigenic Cp and Cu in foals were extremely low at 1 wk. Serum Cp had the lowest...
Kofler J, Kübber-Heiss A, Schilcher F.Clinical, ultrasonographic and pathological findings of a cutaneous, multilocular T-cell lymphosarcoma (malignant lymphoma) in a 13-year-old, brown Austrian warmblood mare are reported. The horse was under clinical observation, and the tumours were sonographically monitored over an 8 month period, revealing worsening of body condition, weight loss, lameness of the left hindlimb and a slight increase in the tumours size. Most of the tumours were covered by normal skin, one showed ulceration. Ultrasonography of the tumours allowed accurate anatomical localization in relation to the adjoining tis...
Jordana J, Folch P, Cuenca R.Twelve clinical biochemical parameters were determined in 97 animals of all age groups and both sexes of the endangered Catalonian donkey breed. Significant sex differences were observed for phospholipid concentration (P<0.01). Evaluating the effect of management practices on the various parameters showed significant differences for total bilirubin (P<0.001) and creatinine (P<0.05) concentrations and gamma-glutamyltransferase (P<0.05) activity. Moreover, it was observed that inorganic phosphorus concentration decreased with age (P<0.001), whereas albumin and triglyceride concent...
Ruohoniemi M, Ryhänen V, Tulamo RM.Radiographic findings in the navicular bone and distal interphalangeal joint as well as the ossification status of the collateral cartilages of the distal phalanx were evaluated in 100 Finnhorse cadaver forefeet. The most common shapes of the proximal articular margin of the navicular bone were convex and straight. Remodeling of the navicular bone was common, especially on the lateral extremity. No bony fragments were identified at the distal flexor margin even though this area appeared irregular in several feet. Several large, rounded or lollipop-shaped synovial invaginations were identified ...
Warmerdam EP.Ultrasonography of the femoral artery in the horse, including color, power and spectral Doppler, provides morphologic and dynamic information. This paper describes the use of the techniques in six clinically normal horses and three with femoral artery thrombosis. Useful landmarks for orientation are the saphenous artery and the medial saphenous vein. The lateral circumflex femoral artery can not be visualized. Recognition of the genus descendens artery is complicated due to the presence of multiple distal caudal femoral arteries. The femoral artery feeds a high resistance bed. In normal horses...
Widmer WR, Blevins WE, Jakovljevic S, Levy M, Teclaw RF, Han CM, Hurd CD.A prospective clinical trial comparing adverse postmyelographic effects and myelographic quality of metrizamide and iohexol was conducted. Using a predetermined, randomized assignment, 24 horses exhibiting neurologic signs were administered either metrizamide (180 mgl/ml) or iohexol (180 mgl/ml) via cerebellomedullary puncture. Each horse was evaluated postmyelographically for adverse effects. Myelographic quality was assessed by a numerical scoring method. Adverse effects were observed more frequently with metrizamide (21) compared with iohexol (6) myelography (p < 0.05). Seizures, intensific...
Fischer AT, Vachon AM.Laparoscopic intra-abdominal ligation and removal of cryptorchid testes in horses was evaluated retrospectively in 50 horses that underwent the procedure between 1991 and 1996. Sixty-one cryptorchid testes were removed by one of the following methods; the use of 1) an endoscoping stapling and transection device, 2) an endoscopic clipping device, 3) an endoscopic ligating loop. Monopolar electrosurgery was combined with these methods to facilitate coagulation and cutting of tissue. In 8 horses, 9 testes were retained between the internal and external inguinal rings. The inguinal testes were rem...
Johnson KG, Tyrrell J, Rowe JB, Pethick DW.Abnormal behaviour commonly develops in intensively managed horses. A possible cause is the change in diet occurring when the horse is stabled. An experiment was performed to examine this possibility by manipulating the diet with the feed supplement virginiamycin, as Founderguard. During 4 weeks, 18 horses were fed diets ranging from hay alone to concentrate plus hay in the ratio of 3:1. The rations of half the horses given concentrate were supplemented with Founderguard. Horses eating high concentrate rations displayed abnormal oral behaviours at a higher frequency than those eating only hay....
Ross MW.To correlate scintigraphic and clinical findings of the metatarsophalangeal joint (MTPJ) in Standardbreds, radiographic findings in horses with confirmed MTPJ lameness, and determine if stress reaction and more advanced bone remodelling occurred in the MTPJ, medical records of 114 Standardbreds admitted between September 1993 and April 1995 in which bone scintigraphy included standing lateral and plantar views of the metatarsophalangeal joint (MTPJ) were reviewed. Images obtained using a large field of view gamma camera were evaluated visually for location, definition and intensity of increase...
Vandenput S, Duvivier DH, Votion D, Art T, Lekeux P.The objective of this study was to test the hypothesis that stabled COPD horses can be maintained in clinical remission by replacing hay by grass silage and bedding made of wood shavings (Period B) and of wheat straw (Period C) during 6 weeks, respectively. At the end of these different periods, the pulmonary function of the horses was assessed by mechanics of breathing and arterial blood analyses. These results were compared to those measured in clinical remission obtained after 2 months in pasture (Period A). No significant difference was observed between these 3 periods neither to values ob...
van Schaik AM, van der Pol BA, van der Linde-Sipman JS.A healthy, 10-day-old Welsh A pony colt was totally blind 1 day after arrival at a studfarm. Both eyes appeared normal on external inspection. The young animal had been very distressed during the 40-km journey to the studfarm. Intravenous corticosteroids were administered for 2 days, but did not result in any observable improvement. The animal was euthanized at the owner's request. Both eyes with the optic nerves were removed for histological examination. Both optic nerves showed Wallerian degeneration, a well-known response of peripheral nerves to trauma. The foal, which was not tethered duri...
Manohar M, Goetz TE, Sullivan E, Griffin R.The present study was carried out to examine the effects of phenylbutazone treatment on the pulmonary haemodynamic effects of frusemide in strenuously exercising horses. Using catheter mounted manometers, whose in vivo signals were referenced at the point of the shoulder, heart rate, right atrial, right ventricular and pulmonary vascular pressures were measured in 3 different sets of experiments. Seven Thoroughbreds were subjected to 1) control (no medications), 2) frusemide control and 3) phenylbutazone + frusemide. The experiments were carried out in random order and were separated by 7 days...
La Perle KM, Piercy RJ, Long JF, Blomme EA.Multisystemic, eosinophilic, epitheliotropic disease and intestinal lymphosarcoma were diagnosed in a Paso Fino mare that presented with anorexia and weight loss. The stomach, ileum, cecum, colon, pancreas, and lungs were infiltrated by large numbers of eosinophils forming prominent eosinophilic granulomas, as well as lymphocytes and plasma cells. Two jejunal masses composed of solid sheets of neoplastic lymphocytes were present. In contrast to the regions of inflammation, the infiltrates in these masses did not contain plasma cells, eosinophils, and eosinophilic granulomas. Immunohistochemica...
Bailey SR, Elliott J.Cumulative concentration response curves to 5-hydroxytryptamine (5-HT; 10(-10)-10(-4) mol/l) were constructed using isolated rings of equine digital, facial, tail and coronary arteries (endothelium intact). 5-HT was 17.7 and 41 times more potent as a vasoconstrictor of digital arteries than facial and tail arteries respectively. Removal of the endothelium increased the vasoconstrictor potency of 5-HT in the facial artery by 3.7-fold (P<0.05) but did not alter the sensitivity of digital arteries to 5-HT. Coronary arteries failed to contract to 5-HT. Coronary arteries pre-contracted with U440...
Young LE, Scott GR.In order to assess the reliability and repeatability of transthoracic echocardiography for detecting serial changes in cardiac function in horses, day to day variability of a number of echocardiographic indices of ventricular function were studied. The variables investigated were, from 2-dimensional (2-D) and M-mode echocardiography - aortic diameter in systole (Aos), pulmonary artery diameter in systole (Pas), left ventricular internal diameter in systole (LLVIDs) and diastole (LLVIDd), and left ventricular fractional shortening (%FS) and estimated ejection fraction (EF). From pulsed Doppler ...
Rahmanian MS, Thompson DL, Melrose PA.Gonadotropin-specific primary antisera and gold-conjugated secondary antibodies were used to immunocytochemically localize gonadotropins in the anterior pituitary of intact pony mares. Electron microscopy was then used to characterize the ultrastructure and immunoreactive staining characteristics of equine gonadotropes. Cells containing LH were morphologically indistinguishable from those containing FSH. Gonadotropes were relatively large and commonly had eccentric nuclei. The rough endoplasmic reticulum was well developed and dilated. Secretory granules were present in two morphologically dis...
Nagata S, Miyake YI, Nambo Y, Nagamine N, Watanabe G, Tsunoda N, Taniyama H, Hondo E, Yamada J, Taya K.To examine the physiological role of inhibin in the stallion, a heterologous radioimmunoassay (RIA) based on a bovine RIA was validated and used to measure immunoreactive (ir)-inhibin concentrations in plasma and testicular homogenates. The bioactivity of equine testicular inhibin was also examined using an assay for suppression of FSH secretion from rat anterior pituitary cells. In addition, to identify the cell responsible for secreting testicular inhibin, the localisation of inhibin in the testis was investigated by an immunohistochemical method using a polyclonal antibody against (Tyr30)-p...
Huszar G, Patrizio P, Vigue L, Willets M, Wilker C, Adhoot D, Johnson L.Although in several species there is a relationship between epididymal sperm transport and fertility, in human in vitro fertilization (IVF), spermatozoa recovered from the caput epididymidis or even the rete testis are fertile. We studied two objective markers of sperm maturity in the sperm of men and stallions: creatine kinase (CK) concentrations, which are a measure of cytoplasmic retention in immature spermatozoa, and the ratio of CK-M and CK-B isoforms (% CK-M/[CK-M + CK-B]), which is proportional to the incidence of mature sperm. The CK markers and the fertilizing function are closely rel...
Ammann VJ, Vrins AA, Lavoie JP.The effects of beclomethasone dipropionate on pulmonary function and arterial blood gas values were investigated in horses with chronic obstructive pulmonary disease (COPD). Six mature mares, diagnosed as having COPD based on clinical signs, cytological examination of bronchoalveolar lavage and pulmonary function testing, were used. Beclomethasone dipropionate (3750 microg) was administered b.i.d. for a 2 week period with a metered dose inhaler using a mask. Pulmonary function tests and arterial blood gas analyses were performed at weekly intervals, starting before beclomethasone administratio...
Malecki TM, Jillson GP, Thilsted JP, Elrod J, Torrez-Martinez N, Hjelle B.To determine whether animals had serologic evidence of infection with Sin Nombre virus (SNV). Methods: Prospective serosurvey. Methods: Serum samples were obtained from 145 cats, 85 dogs, 120 horses, and 24 cattle between April 1993 and August 1994 and 54 coyotes between December 1994 and February 1995. Methods: Serum samples were analyzed by western immunoblot assays for reaction with SNV nucleocapsid antigen. Samples with reactivity to SNV nucleocapsid proteins were used to probe multiple-antigen blots containing recombinant fusion proteins derived from prototypic hantaviruses. Lung tissue o...
Cornick JL.A 2-year-old Trakehner filly with pulmonary histoplasmosis is presented. Clinical signs included weight loss, intermittent fever, dyspnea and depression. Diagnosis was based on thoracic radiography, transtracheal wash cytology and lung aspirate cytology. A 5-week regimen of Amphotercin-B administered intravenously resulted in clinical recovery and return of the animal to normal activity. A brief review of histoplasmosis in man and animal is included.
Mackenzie CJ, Carslake HB, Robin M, Kent RJ, Malalana F.An 8-year-old mare was presented for investigation of a 1-month history of blepharospasm, eyelid swelling, corneal edema, and ocular discharge of the right eye (OD). Ophthalmic examination confirmed mucopurulent ocular discharge, conjunctival hyperemia, and a dry, dull appearance to the cornea OD. Schirmer tear test results confirmed an absence of tear production OD (0 mm/min) consistent with keratoconjunctivitis sicca. Treatment with topical 0.2% cyclosporine A resulted in an improvement in clinical signs. An episcleral cyclosporine A implant was placed under standing sedation 5 days after in...
Wyse CA, Nixon C, McLaughlin M, Dowell FJ, Philbey AW.The aim of this study was to characterise the expression of haem oxygenase-1 (HO-1) in healthy lung tissue from horses and to measure its activity. Samples of lung tissue were collected from six horses euthanased for reasons other than respiratory disease. HO-1 expression and activity were detected in type II alveolar epithelial cells, macrophages and neutrophils in all the samples examined. The activity was dependent on the presence of NADPH and inhibited quantitatively by the addition of increasing concentrations of a competitive inhibitor of HO-1, tin mesoporphyrin IX.
Stoughton WB, Begin S, Outman S, Stryhn H, Yu J, Conboy G, Nielsen MK.Widespread overuse of anthelmintics has produced a growing population of intestinal parasites resistant to control measures. A paradigm shift in equine parasite control is warranted to prevent continued resistance development and maintain equine health. Small strongyles, which are ubiquitous in horses, are currently the most important intestinal parasites of adult horses. Sustainable management programs consider the variation in egg shedding by individual horses, and varied risks associated with age, use, density, climate, and environment. To develop regional recommendations for Prince Edward ...
Schulman ML, Marlow CH, Nurton JP.The data and an analysis of the statistical summaries from the 'Return of Mares' of the General Stud Book of The Jockey Club of Southern Africa from 1975-1999 are presented. The total number of mares covered per season ranged from 7393 (1992) to 5180 (1995). The total living produce in the period surveyed was 95 317 foals. The categories of data examined include: the total number of mares covered per season; the total numbers and percentage of their living produce; the total numbers and percentage dead produce, 'slips' and foals born dead, barren and 'no return' mares; and the total number of ...
Galuppo LD, Stover SM, Jensen DG, Willits NH.To compare drilling, tapping, and screw-insertion torque, force, and time for the 4.5-mm AO and 6.5-mm Acutrak Plus (AP) bone screws, and to compare the mechanical shear strength and stiffness of a simulated complete lateral condylar fracture of the equine third metacarpal bone (MC3) stabilized with either an AO or AP screw. Methods: In vitro biomechanical assessment of screw-insertion variables, and shear failure tests of a bone-screw-stabilized simulated lateral condylar fracture. Methods: Eight pairs of cadaveric equine MC3s Methods: Metacarpi were placed in a fixture and centered on a biax...
Kernot N, Butler R, Randle H.Conditions of the equine caudal neck (C5-C7) are thought to be associated with various clinical signs. However, little investigation has been undertaken to isolate clinical indicators associated with specific conditions of the equine caudal cervical spine. This systematic review aimed to evaluate associations of clinical signs with anatomical malformation of caudal cervical vertebrae, spinal cord compression of the caudal cervical spine, and arthropathy of the caudal cervical articular process joints (APJs). A literature search was carried out using Google Scholar in accordance with PRISMA (Pr...
Brinsko SP, Squires EL, Pickett BW, Nett TM.The objective of this study was to determine if prolonged pulsatile administration of homologous gonadotropin-releasing hormone (GnRH) at therapeutic or 5x therapeutic doses would cause down-regulation of the stallion's hypothalamic-pituitary-testicular axis. Fifteen stallions were randomly assigned to three treatment groups (n=5/group) and received a 0.5 ml subcutaneous dose of saline (group 1), 50 microg GnRH (group 2), or 250 microg GnRH (group 3) every 2 hours for 75 days. Weekly evaluations of follicle stimulating hormone, luteinizing hormone, and testosterone and monthly evaluations of d...
Arden WA, Stick JA, Parks AH, Chou CC, Slocombe RF.Physiologic effects of 1 hour of ischemia and 1 hour of reperfusion on equine jejunum and protective effects of systemic administration of dimethyl sulfoxide (DMSO, 1 g/kg of body weight) were investigated in 18 ponies, using neurally intact segments of jejunum perfused at constant flow with heparinized blood. Ponies were allotted to 4 groups: group 1, saline solution administered (control, n = 3); group 2, DMSO administered (DMSO, n = 3); group 3, ischemia induced and saline solution administered (ischemia, n = 6); and group 4, ischemia induced and DMSO administered (ischemia-DMSO, n = 6). In...
O'Donnell MM, Harris HM, O'Toole PW, Ross RP.We report the draft genome sequence of Lactobacillus equi strain DPC6820, isolated from equine feces. L. equi is a predominant Lactobacillus species in the horse hindgut microbiota. An examination of the genome identified genes and enzymes highlighting L. equi adaptations to the herbivorous gastrointestinal tract of the horse, including fructan hydrolases. This genome sequence may help us further understand the microbial ecology of the equine hindgut and the influence lactobacilli have on it.
Smith CM, Steffey EP, Baggot JD, Dunlop CI, Farver TB.Inhalation anesthetics decrease the clearance of some drugs that are eliminated by renal excretion. The purpose of the study reported here was to investigate the effects of halothane anesthesia on the pharmacokinetics and urinary excretion of gentamicin sulfate, using the horse as a model. Using a crossover design, pharmacokinetic values after a single IV dose of gentamicin (4 mg/kg) were compared in halothane-anesthetized and unanesthetized horses. Compared with unanesthetized horses, the anesthetized horses had significant decreases in total body clearance (P less than 0.01) and apparent vol...
Wauters J, Pille F, Martens A, Franck T, Serteyn D, Gasthuys F, Meyer E.Equine joint infection is a life-threatening disorder, and confirmation of the diagnosis can be difficult. Synovial fluid biomarkers may assist the discrimination between infectious and noninfectious joint disease. Objective: This study investigates whether the immunological detection of total and enzymatically active myeloperoxidase (MPO) assists the diagnosis of joint infection in horses. Methods: The following 4 sample groups were included: healthy; osteochondritis dissecans (OCD); traumatic synovitis; and culture-confirmed infected joints. Synovial fluid was analysed for total MPO by a hor...
Dunkel BM, Wilkins PA.A nutritional plan should be incorporated into every treatment plan of the critically ill patient. Weight loss and cachexia are the result of prevalence of catabolic processes over anabolic processes in addition to absolute or relative increased demands and decreased food intake.
Every LJ, Hostnik ET, Hostnik LD, Yardley J, Shore-Khirallah AT, Thompson A, Linn SC.Tracheal collapse in horses is reportedly uncommon; however, American Miniature Horses are more commonly affected. There is no description of the tracheal luminal diameter of American Miniature Horses, making early detection of tracheal luminal narrowing difficult. Objective: To 1) describe radiographic tracheal luminal diameter in clinically normal American Miniature Horses, 2) report the prevalence of subclinical tracheal collapse in a population of American Miniature Horses, and 3) use tracheal videofluoroscopy to quantify variation in tracheal luminal diameter throughout the respiratory c...
Michlik KM, Biazik AK, Henklewski RZ, Szmigielska MA, Nicpoń JM, Pasławska U.Quadricuspid aortic valve (QAV) and ventricular septal defect (VSD) are congenital heart defects and have been described in both human and veterinary medical literature. Methods: A 5-year-old half-bred bay stallion was referred for surgical castration. Cardiac murmurs were heard on the presurgical clinical examination and the cardiac examination revealed subcutaneous oedema, tachycardia with a precodrial thrill and a grade 5/6 pansystolic murmur, which was heard on auscultation of the right and left side of the chest. Examination of the B-mode echocardiograms revealed the presence of a QAV (on...
Buntenkötter K, Osmers M, Schenk I, Schänzer W, Machnik M, Düe M, Kietzmann M.Although acetylsalicylic acid (ASA) is not frequently used as a therapeutic agent in horses, its metabolite SA is of special interest in equestrianism since it is a natural component of many plants used as horse feed. This led to the establishment of thresholds by horse sport organizations for SA in urine and plasma. The aim of this study was to investigate plasma and urine concentrations of salicylic acid (SA) after oral administration of three different single dosages (12.5 mg/kg, 25 mg/kg and 50 mg/kg) of acetylsalicylic acid (ASA) to eight horses in a cross-over designed study. Results:...
Boldt E.Horses 15 years of age and older now account for a significant portion of the equine population. Integrative therapies can provide important diagnostic and treatment tools for managing and maintaining the health of geriatric horses. Aged horses are often afflicted with chronic disease processes that are difficult to effectively manage with conventional medicinal approaches, such as laminitis and osteoarthritis. Diagnostic and therapeutic approaches using integrative therapies, such as acupuncture and spinal manipulation, are presented in this article for managing aged horses with metabolic dis...
Yovich JV, Turner AS, Stashak TS, McIlwraith CW.Lateral or medial luxation of the metacarpophalangeal or metatarsophalangeal (fetlock) joint in 10 horses is presented. Closed and open fetlock luxation each occurred in five horses. Horses were treated by cast immobilisation after debridement of soft tissue and joint lavage in cases of open luxations. Suture apposition of a ruptured collateral ligament was attempted in three cases. Antibiotic therapy was used in all cases of open fetlock luxation but non-steroidal anti-inflammatory medication was used inconsistently. Whether closed or open, fetlock luxations had a good prognosis for return to...
Lescun TB, Hawkins JF, Siems JJ.A 6-month-old warmblood filly had traumatic rupture in the gastrocnemius and superficial digital flexor muscles of the left hind limb. A modified Thomas splint-cast combination, which was custom fitted to the limb, was placed to prevent further disruption of the caudal reciprocal apparatus. The external coaptation device was removed after 21 days. The horse developed lesions consistent with osteochondrosis of the femoropatellar articulation within 8 weeks of the initial injury. Examination of the horse 6 months after injury revealed fibrous healing of the muscles and restoration of caudal reci...