Surgery for horses encompasses a range of procedures performed to diagnose, treat, or manage various medical conditions. These procedures may involve soft tissue or orthopedic interventions and require specialized techniques to accommodate the unique anatomical and physiological characteristics of equines. Common surgical procedures in horses include colic surgery, fracture repair, and arthroscopy. The success of equine surgery depends on numerous factors, including the type of procedure, the horse's overall health, and post-operative care. This page compiles peer-reviewed research studies and scholarly articles that explore surgical techniques, outcomes, and advancements in equine surgical practices.
Compostella F, Tremaine WH, Franklin SH.To investigate causes of respiratory noises in horses following prosthetic laryngoplasty (with or without a ventriculocordectomy) and to examine potential associations between degree of arytenoid abduction and the presence of other upper respiratory tract (URT) abnormalities, including right-sided collapse. Methods: Clinical records and dynamic videoendoscopic recordings were examined from horses presented between 1995 and 2010 for investigation of respiratory noise during exercise, following a prosthetic laryngoplasty (+/- a ventriculocordectomy). Relationships between the degree of left aryt...
Anderson SL, Blackford JT, Kelmer SG.This study describes the outcome and complications in horses that had a closed, one-stage, stapled, functional, end-to-end (COSFE) jejuno-ileal anastomosis (JIA) following resection of compromised small intestine. Medical records were reviewed to identify all horses that had a COSFE JIA performed during exploratory laparotomy and to determine post-operative complications and final outcome. All 5 horses that were identified had successful COSFE JIA with resection of various amounts of distal jejunum and proximal ileum. Post-operative ileus occurred in 1 of the 5 horses. All horses survived at l...
Tatz AJ, Segev G, Steinman A, Berlin D, Milgram J, Kelmer G.There is a consensus in the veterinary literature that Parascaris equorum (ascarid) impaction carries a poor prognosis. Hence surgery is often delayed and foals are often subjected to euthanasia after diagnosis of ascarid impaction is established. Our clinical impression was that ascarid impaction carries a better prognosis than previously reported. Objective: Our expectation was that manually evacuating the impaction into the caecum, thus refraining from opening the small intestine, would improve the prognosis for survival of horses with ascarid impaction. The aim of this study was to examine...
Lepage OM, Doumbia A, Perron-Lepage MF, Gangl M.Maggot debridement therapy is a long-established tool to promote wound healing. Objective: To describe and assess the results of this technique in equids with various lesions. Methods: Retrospective analysis performed on cases in which, depending on clinical case, type, size and location of the wound, maggots were applied either in direct or indirect contact with the wound. Results: Treated cases (n = 41) included horses with foot pathology (n = 9), laceration of the limbs (n = 15), other soft tissue abscesses or wounds (n = 6), fistulous withers (n = 5), other musculoskeletal infection (n = 2...
Janicek J, Lopes MA, Wilson DA, Reed S, Keegan KG.Fibrotic myopathy can cause incapacitating gait abnormalities. Transection of the fibrotic mass followed by early post operative exercise is the best treatment for fibrotic myopathy. A laser may be used to transect the fibrotic mass. Assessment of the effectiveness of therapies for fibrotic myopathy has been limited to subjective evaluation. Objective: To objectively assess gait abnormalities associated with fibrotic myopathy before and after laser fibrotomy followed by early post operative exercise. Methods: Kinematic evaluation of horses with fibrotic myopathy walking and trotting on a tread...
Velez IC, Arnold C, Jacobson CC, Norris JD, Choi YH, Edwards JF, Hayden SS, Hinrichs K.Transvaginal ultrasound-guided follicle aspiration (TVA) is performed clinically but there is little information available on complications associated with this procedure. Objective: It is possible that TVA is associated with damage to the ovary and may induce peritonitis or peritoneal adhesions. This study was conducted to determine the effect of repeated TVA on mare health and ovarian status. Methods: Thirty-two mares were used for oocyte recovery via repeated TVA over a 3 year period; different mares were used each year. In Year 1, ovarian status was monitored in 11 mares by transrectal pal...
McCormick JD, Valdez R, Rakestraw PC, Varner DD, Blanchard TL, Cavinder CA, Sudderth AK, Kiser A, Love CC.Management decisions on unilateral orchiectomy are often influenced by the potential for post operative return to successful breeding. The effects of 2 surgical methods (first intention [FI] vs. second intention [SI] incision healing) for unilateral orchiectomy on resulting semen quality and scrotal temperature were evaluated. Objective: To evaluate the effects of 2 surgical unilateral orchiectomy techniques on scrotal healing, size of the remaining testis and post operative sperm quality. Methods: Unilateral orchiectomy was performed on mature Miniature Horse stallions. Semen was collected pr...
Barnett TP, O'Leary JM, Parkin TD, Dixon PM, Barakzai SZ.To (1) assess long-term maintenance of arytenoid cartilage abduction (ACA) after laryngoplasty (LP); and (2) correlate the residual grade of ACA and postoperative abductory loss with arytenoid cartilage stability (ACS) during exercise. Methods: Case series. Methods: Horses re-examined after laryngoplasty (n = 33). Methods: Of 89 LP horses (2005-2010), 33 had historic ACA data available and upper airway endoscopy at rest and during over-ground exercise (mean, 33 months; range, 4-71 months) after surgery. ACA grade at 1 and 6 weeks postoperatively were correlated to long-term ACA grade. Effects ...
Kilcoyne I, Watson JL, Kass PH, Spier SJ.To determine the incidence of complications and identify risk factors associated with development of complications following routine castration of equids. Methods: Retrospective case series. Animals-311 horses, 10 mules, and 3 donkeys. Methods: Medical records of equids undergoing routine castration were reviewed. Age, breed, surgical techniques (closed vs semiclosed castration and use of ligatures), anesthesia method (general IV anesthesia vs standing sedation with local anesthesia) and repeated administration of IV anesthetic agents, administration of antimicrobials and anti-inflammatory dru...
Boyce MK, Trumble TN, Carlson CS, Groschen DM, Merritt KA, Brown MP.Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA). Methods: An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) ...
Cadby JA, David F, van de Lest C, Bosch G, van Weeren PR, Snedeker JG, van Schie HT.Injuries in energy-storing tendons are common in both horses and man. The high prevalence of reinjury and the relatively poor prognosis for returning to preinjury performance levels warrant further research, for which well characterised models would be very helpful. Objective: Given the clinical similarities in tendinopathy of energy-storing tendons, we hypothesised that a recently developed experimental model of equine tendon injury would display many of the characteristics of clinical tendinopathy and could therefore be of use for both species, thus providing comparative insight to the human...
Ahern BJ, Showalter BL, Elliott DM, Richardson DW, Getman LM.To compare the in vitro biomechanical properties of a 4.5 mm narrow locking compression plate (PIP-LCP) with 2 abaxially located transarticular screws and a 4.5 mm limited contact dynamic compression plate (LC-DCP) with 2 abaxially located transarticular screws using equine pasterns. Methods: Experimental. Paired in vitro biomechanical testing of 2 methods for stabilizing adult equine forelimb PIP joints. Methods: Adult equine forelimbs (n = 8 pairs). Methods: Each pair of PIP joints were randomly instrumented with either a PIP-LCP or LC-DCP plate axially and 2 parasagitally positioned 5.5 mm ...
Bischofberger AS, Hadidane I, Wereszka MM, Perkins NR, Jeffcott LB, Dart AJ.To determine the effect of horse age and laryngeal prosthesis location on rima glottidis area in cadaveric larynges. Methods: Experimental study. Methods: Cadaveric equine larynges (n = 40). Methods: Specimens were grouped by age: group 1, ≤5 years (n = 18); group 2, >5 to ≤10 years (n = 12); group 3, >10 years (n = 10). A cranial prosthesis was placed through the dorsal cricoid spine at 70% of the distance of the total cricoid length measured from the caudal rim. A dorsal prosthesis was placed through the caudal rim of the cricoid on the dorsal midline. A lateral prosthesis was plac...
Anderson SL, Bracamonte JL, Hendrick S, Carmalt JL, Wilson DG.To compare bursting strength and failure mode between ventral median celiotomies closed with USP 7 braided polydioxanone (7PD) or USP 2 polyglactin 910 (2PG). Methods: Ex vivo experimental. Methods: Equine cadavers (n = 10). Methods: A 25 cm ventral median celiotomy was created in fresh equine cadavers. A 200 L polyurethane bladder was inserted into the abdomen. Celiotomies were closed in a simple continuous pattern with 2 sections of 7PD or 2PG. The bladder was inflated with compressed air until construct failure. The horses' signalment, body weight, suture type, failure mode (suture or abdom...
Arnold CE, Taylor T, Chaffin MK, Schott HC, Caron JP.To report technique for, and outcome after, nephrectomy through a ventral median celiotomy in equids. Methods: Case series. Methods: Equids with unilateral renal disease (n = 6), aged 2 months to 18 years, weighing 90-434 kg. Methods: A ventral median celiotomy was used to access the left or right kidney. To facilitate surgical exposure, the small intestine was reflected towards the diaphragm using laparotomy sponges and the ascending colon was exteriorized and in some cases evacuated. The peritoneum over the affected kidney was incised and blunt dissection used to free the kidney from the ret...
Carmalt JL, Linn KA.To describe a large segmental (sub-total) mandibulectomy for removal of an undifferentiated sarcoma in a horse. Methods: Clinical report. Methods: A 10-year-old mare. Methods: A combination of methods including computed tomography (CT) were used to diagnose a large undifferentiated sarcoma of the right mandible. A large segmental mandibulectomy extending from 3 cm below the right temporomandibular joint to immediately caudal to tooth 407 was used to perform an en-bloc resection of the mass under general anesthesia. Results: Surgery time was 11 hours and 35 minutes and total anesthesia time, 12...
Anderson SL, Bracamonte JL, Hendrick S, Carmalt JL, Wilson DG.To compare bursting strength and failure mode between ventral median (VM) and right ventral paramedian (RVP) celiotomies closed with 1 section of USP 7 braided polydioxanone (7PD). Methods: Ex vivo experimental. Methods: Equine cadavers (n = 12). Methods: A 25 cm VM or RVP (positioned 5 cm lateral to the linea alba) celiotomy was created in fresh equine cadavers. A 200 L polyurethane bladder was inserted into the abdomen. Celiotomies were closed in a simple continuous pattern with 1 section of 7PD. The bladder was inflated with compressed air until construct failure. Horse signalment, body wei...
Borg H, Carmalt JL.To determine the frequency of postoperative septic arthritis after elective arthroscopy in the absence of prophylactic antimicrobial therapy and to report complication rate of 444 consecutive equine arthroscopies. Methods: Retrospective case series. Methods: Horses (n = 444). Methods: Medical records of 444 consecutive elective equine arthroscopies (2008-2010) were reviewed. Horses that had septic arthritis on admission or those admitted for tenoscopy and bursoscopy, or had arthroscopic assisted internal fracture fixation were not included. Age and sex of horse, duration of anesthesia, joint e...
Olstad K, Hendrickson EH, Carlson CS, Ekman S, Dolvik NI.To transect blood vessels within epiphyseal cartilage canals and observe whether this resulted in ischaemic chondronecrosis, an associated focal delay in enchondral ossification [osteochondrosis (OC)] and pathological cartilage fracture [osteochondrosis dissecans (OCD)] in the distal femur of foals, with potential translational value to the pathogenesis of juvenile osteochondritis dissecans (JOCD) in children. Methods: Ten Norwegian Fjord Pony foals were operated at the age of 13-15 days. Two vessels supplying the epiphyseal growth cartilage of the lateral trochlear ridge of the left distal fe...
Arnold CE, Love CC.Intraluminal masses in the oviduct might cause infertility and/or subfertility in mares by preventing transport of ova, sperm, or both, to the site of fertilization or the embryo into the uterus. Currently, there is no clinical test for oviductal patency in mares. The objective was to determine if the passage of microspheres from the oviduct to the uterus was associated with the presence or absence of intraluminal masses. In this trial, a standing laparoscopic technique was used to cannulate the oviducts and instill 15-μm fluorescent beads in 16 light-breed mares. At 48 hours after surgery, u...
Renzi S, Riccò S, Dotti S, Sesso L, Grolli S, Cornali M, Carlin S, Patruno M, Cinotti S, Ferrari M.The use of Mesenchymal Stromal Cells (MSCs) in orthopedic practice has recently and rapidly acquired an important role. Therapies based on the use of MSCs for the treatment of acute injuries as well as chronic inflammatory disorders are gradually becoming clinical routine. These cells have demonstrated intriguing therapeutic potentialities (i.e.: inflammation control, tissue regeneration and pathological scar prevention), that have been taken into consideration for use in both human and veterinary medicine. In particular, horses represent high performance athletes considered models for human p...
Snyder LB, Wendt-Hornickle E.The purpose of this article is to update the community of veterinarians performing general anesthesia in horses on fluid therapy. The rationale behind intraoperative fluid therapy, fluid dynamics, and various fluid options (crystalloids, hypertonic saline, colloids) is discussed. Additionally, electrolytes (calcium, potassium, and sodium) are included in the discussion in relation to general anesthesia and intraoperative fluid management.
Moens Y.The mechanical ventilation of horses during anesthesia remains a crucial option for optimal anesthetic management, if the possible negative cardiovascular side effects are managed, because this species is prone to hypercapnia and hypoxemia. The combined use of capnography and pitot-based spirometry provide complementary information on ventilation and respiratory mechanics, respectively. This facilitates management of mechanical ventilation in conditions of changing respiratory system compliance (ie, laparoscopy) and when investigating new ventilatory strategies including alveolar recruitment m...
Woodhouse KJ, Brosnan RJ, Nguyen KQ, Moniz GW, Galuppo LD.To test the hypothesis that postanesthetic sedation with romifidine would dose-dependently improve recovery quality of recovery from isoflurane anesthesia in horses more than postanesthetic sedation with xylazine. Methods: Prospective, randomized, blinded clinical trial. Methods: 101 healthy adult horses examined at the University of California-Davis Veterinary Medical Teaching Hospital from 2007 to 2009. Methods: Horses were sedated with xylazine, and anesthesia was induced with guaifenesin, diazepam, and ketamine via a standardized drug protocol. Anesthesia for surgical or diagnostic procedu...
Link KA, Koenig JB, Silveira A, Plattner BL, Lillie BN.To compare the effect of extracorporeal shock wave therapy (ESWT) on expression of fibroblast growth factor-7 (FGF-7), transforming growth factor-β1 (TGF-β1), insulin-like growth factor-1 (IGF-1), platelet-derived growth factor-A (PDGF), and vascular endothelial growth factor-A (VEGF) in skin with surgically created skin wounds and intact skin in horses. Methods: 14 healthy horses. Methods: 8 horses were treated with ESWT at 6 locations along the neck at 36, 24, 12, 6, 2, or 1 hour prior to collection of full-thickness biopsy specimens from each location; a control specimen was collected fro...
Easley JT, Freeman DE.To describe successful surgical treatment of bilateral mucocele in an American Miniature horse using a single bone flap to approach right and left paranasal sinuses simultaneously. Methods: Clinical report. Methods: A castrated 6-year-old American Miniature Horse with a bilateral mucocele of the paranasal sinuses. Methods: A single bilateral frontonasal sinus flap was used in a standing procedure to access the left and right conchofrontal sinuses simultaneously to remove the mucous contents and to establish permanent drainage into the nasal cavities. Results: The novel procedure used in this h...
Kümmerle JM, Kummer MR.To describe the arthroscopically accessible anatomy of the tarsal collateral ligaments in the horse. Methods: Descriptive study. Methods: Cadaveric equine hind limbs (n = 24) obtained from horses without tarsal disease. Methods: Two pairs of tarsal joints were used to obtain silicone models of the tarsocrural joint and dissect the tarsal collateral ligaments (CLs). Ten pairs of tarsocrural joints had arthroscopic exploration and the accessible parts of the tarsal CLs were marked with an arthroscopic hook knife. Subsequently, the limbs were dissected and the marked positions were allocated to t...
Bischofberger AS, Wereszka MM, Hadidane I, Perkins NR, Jeffcott LB, Dart AJ.To evaluate the effect of 3 laryngeal prostheses alone or in combination on rima glottidis area in horses. Methods: Experimental randomized design. Methods: Cadaveric equine larynges (n = 22). Methods: Three prostheses were preplaced in each of 14 larynges. Rima glottidis area was measured after loading each suture in 5 Newton (N) increments from 0 N to 35 N. In 8 larynges, the 3 prostheses were tied alone or in combination at a fixed load of 15 N and rima glottidis area measured. Results: Rima glottidis cross-sectional area increased as the load on each prosthesis increased with maximum area ...
Richardson DW.The common conditions affecting the urogenital tract of the neonatal foal and their medical and surgical management are described. Early recognition and treatment of serious abnormalities are necessary for a successful outcome in the equine neonate.
Saulez MN, Burton A, Steyl JC, Williams JH, Clift SJ.The medical records of four horses whose intestines had been perforated by metallic wires were reviewed. Three of the horses developed acute colic, and the other progressively lost weight and became inappetent and pyrexic. Metallic wires were detected either by exploratory laparotomy or postmortem examination. In three of the horses there were adhesions containing an encapsulated metallic wire in the small intestine, and in the other the wire was contained within an abscess with multiple adhesions involving the liver, spleen and mesentery.
Scruton C, Baxter GM, Cross MW, Frisbie DD.Anecdotal reports suggest that laser-facilitated arthrodesis of the distal tarsal joints improves the prognosis compared with intra-articular drilling but no objective comparisons have been performed. Objective: To evaluate intra-articular drilling and laser-facilitated arthrodesis using in situ and in vivo techniques. Methods: Fourteen cadaver limbs were evaluated in situ for chondrocyte viability after both surgical techniques. In vivo, one randomly selected limb was subjected to laser-facilitated arthrodesis and the other underwent intra-articular drilling in 6 normal horses. Clinical exami...
Kelmer G.In recent years important advancements in colic surgery have led to improved prediction of survival rates, better survival rates, and decreased complication rates. This article describes several modalities to combat and prevent incisional hernia and intestinal adhesion formation in horses undergoing colic surgery. These modalities have had a positive impact on reducing complications in horses after surgery.
Firth EC.The clinical and necropsy findings of three cases of diaphragmatic hernia admitted to Ontario Veterinary College between September 1973 and August 1974 are described. The physical signs of these and other reported cases are discussed, as are methods of diagnosis. Definitive diagnosis is best arrived at by exploratory laparotomy.
Christman C.A 19-year-old, Arabian gelding was presented for left hindlimb lameness and deviation of the hoof wall. Radiographs revealed a semicircular, radiolucent area in the lateral edge of the distal phalanx. Three distinct keratomas were successfully removed following hoof wall resection. Kératomes multiples sur le pied d’un cheval. Un cheval Arabe hongre âgé de 19 ans a été présenté pour une boiterie du membre postérieur gauche et une déviation de la paroi du sabot. La radiographie a révélé une région semi-circulaire radiotransparente au niveau du bord latéral de la phalange distale....
Ragle CA.The equine head is especially prone to trauma from kicks, collisions, entrapments, and falls. The specialized structures of the equine head are important in both function and appearance. When injury causes either loss of function or cosmesis, timely treatment is paramount. This article discusses the occurrence and therapy of trauma to the equine head, including fractures of the mandible and premaxilla, facial bone, hyoid apparatus, and skull base.
Jardine JE, Nesbit JW.A large abdominal mass in a 3-year-old filly was discovered clinically and removed and examined after the horse had been humanely killed. Histologically, three different tissue types were noted, occurring in equal amounts: epithelium largely in the form of well-differentiated tubules, multifocally distributed cell-dense foci of blastema, and myxoid to fibrous stroma. A diagnosis of triphasic nephroblastoma, a rare tumour in the horse, was made on the basis of microscopical findings. The finding of numerous glomeruloid structures confirmed the diagnosis and assisted in distinguishing the tumour...
Tnibar MA.To describe a surgical technique for splitting the proximal third of the medial patellar ligament (MPL) in horses and ponies with upward fixation of the patella (UFP), and to report outcome. Methods: Prospective clinical study. Methods: Four horses and 3 Shetland ponies. Methods: With ultrasound guidance, the proximal third of the MPL was split by percutaneous use of a no. 15 scalpel blade. The rationale for this surgical procedure was to induce a localized desmitis with subsequent ligament thickening. No anti-inflammatory drugs were administered, and horses and ponies were exercised the day a...
Gerlach K, Vervuert I, Gittel C, Köhler L, Schmidt N, Winter K, Berner D, Troillet A, Schulz-Kornas E.Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports considering the morphology of nasal conchal bullae in small horse breeds such as Shetland ponies. The aim of the present study was to evaluate the size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reco...
Comino F, Giusto G, Caramello V, Gandini M.The Serra and Reimer emasculators are frequently used in equine orchiectomy. They differ in jaw profile and the mechanism by which they achieve haemostasis. Objective: To investigate whether the haemostatic capacities of the Reimer and Serra emasculators in open and closed castration differ, to compare the haemostatic capacities of each emasculator in both open and closed castration, and to assess whether the tensile strength of the parietal tunic in closed castration differs according to whether a Reimer or Serra emasculator is used. Methods: Ex vivo randomised study. Methods: Eighty equine c...
Camus AC, Burba DJ, Valdes MA, Taylor HW.A 21-year-old female American Saddle Horse with a prominent swelling on the ventral aspect of the right hemimandible and radiographic evidence of a bone cyst was examined. The cyst cavity was surgically explored and was found to contain mucinous fluid and sheets of keratin. Microscopically, the cyst was lined by well-differentiated squamous epithelium characterized by various degrees of hyperkeratosis and parakeratosis. The stromal component varied from scant areas in which epithelium was closely apposed to bone to wide regions of dense connective tissue that contained fragments of keratin sur...
Bertone AL, McIlwraith CW, Powers BE, Trotter GW, Stashak TS.Osteochondritis dissecans (OCD) and subchondral cyst-like lesions in 13 shoulders of 11 horses were treated arthroscopically by curettage and lavage. Lameness decreased in all 11 horses. Nine horses were sound, five of them athletically sound, after 5 to 20 months. Complications included the development of subchondral cyst-like lesions and signs of degenerative joint disease. Arthroscopic surgery of the equine shoulder can be done through two portals, one for the arthroscope and one for an instrument. A few hand instruments such as a probe, Ferris-Smith rongeurs, and small, large, and right-an...
Thomas HL, Livesey MA, Caswell JL.Multiple aneurysmal bone cysts (ABCs) are previously unreported in horses. An ABC was diagnosed in the left 3rd metacarpal of a Thoroughbred foal, which partially resolved following surgical curettage. A 2nd ABC developed in the left tibia, 7 wk postoperatively, and the foal was euthanized.
Moore CP, Grevan VL, Champagne ES, Collins BK, Collier LL.Five horses presented with unilateral pink, smooth, nonulcerated conjunctival masses with histologic features characteristic of inflammatory pseudotumors, i.e. proliferative inflammatory lesions clinically resembling true neoplasia. Although causes for the inflammatory lesions were not determined, based on the presence histologically of mononuclear (predominantly lymphocytic) inflammatory cell infiltrates and the absence of infectious agents, parasites or foreign bodies, an immune-mediated pathogenesis was suspected. Affected horses ranged from 5 to 8 years of age with no apparent breed or sex...
Anderson SL, Panizzi L, Bracamonte J.An 8-month-old Andalusian filly was treated for jejunal perforations due to ingestion of a porcupine quill. During exploratory laparotomy, 2 separate stapled side-to-side jejunojejunal resection and anastomoses were performed. Post-operative complications after 2 years follow-up included mild incisional herniation following incisional infection and chronic intermittent colic. Perforation jéjunale causée par l’ingestion d’une aiguille de porc-épic chez un cheval. Une pouliche d’Andalousie âgée de 8 mois a été traitée pour des perforations jéjunales causées par l’ingestion d’...
Fretz PB, Donecker JM.The outcome of surgical treatment of angular limb deformities in 29 foals was evaluated through long-term monitoring of athletic performance. Foals were placed into 1 of 2 groups, depending on the site of the angular limb deformity. In group 1 foals, the deformity involved the carpus of distal end of the radius. In group 2 foals, the deformity involved the distal end of the 3rd metacarpal or metatarsal bone. Group 1 contained 20 foals and group 2 contained 11 foals. Two foals were in both groups. Sixteen foals in group 1 and 4 foals in group 2 progressed to some form of athletic use. The under...