Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Laviada MD, Arias M, Sánchez-Vizcaíno JM.The structural and non-structural proteins induced by African horsesickness virus serotype 4 (AHSV-4) in infected Vero cells were analysed by SDS-PAGE. Twenty-two virus-induced polypeptides were detected in infected cells by comparison with the polypeptides of mock-infected cells, of which four major (VP2, VP3, VP5 and VP7) and three minor (VP1, VP4 and VP6) structural proteins and four non-structural proteins (P58, P48, P21 and P20) were shown to be virus-coded, as deduced from electrophoretic and antigenic studies of purified virions and infected cells. The proteins that elicit the major ant...
Hank AM, Hoffmann WE, Sanecki RK, Schaeffer DJ, Dorner JL.Automated and semiautomated assays were developed and validated for the determination of equine alkaline phosphatase isoenzymes including intestinal (IALP), bone (BALP), and liver (LALP). The addition of levamisole selectively inhibited more than 97% of LALP while inhibiting only 55% of IALP. Because these percentages were highly reproducible in an automated system, the IALP activity could be calculated in a sample. Bone alkaline phosphatase isoenzyme was selectively precipitated by adding an equal volume of wheat germ agglutinin (5 mg/mL), incubating for 30 minutes at 37 degrees C, and centri...
Leidl W.1. At present there is a wide field of applications for ultrasonography in gynaecological examinations. 2. Pregnancy (under clinical conditions) may be diagnosed in mares from day 14, in cows from day 25/26, in small ruminants from day 35, in sows from day 28/30, in bitches from day 25/28 and in queens from day 20/25 on, either by demonstrating the embryonic vesicle or the embryo or fetus. 3. Control of ovulation is gaining importance in the mare, especially in artificial insemination. 4. The diagnosis of pathological processes in the uterus of mares, bitches and queens is improved considerabl...
Davies HM, McCarthy RN, Jeffcott LB.Stacked rectangular rosette strain gages were used to measure surface bone strain on the dorsomedial cortex of the third metacarpal bones in 6 adult Thoroughbred horses during treadmill exercise. The peak principal compressive and tensile strains, angle of the peak strains and strain rate during loading were calculated and compared with speed and gait. At speeds from 4 to 14 m/s loading on the metacarpus resulted in compression of the dorsomedial cortex. Tension only occurred consistently in 1 forelimb of 1 horse at the walk (2 m/s). The angle of peak compression was within 10 degrees of the l...
Hamra JG, Kamerling SG, Wolfsheimer KJ, Bagwell CA.Diurnal variation in nociceptive sensitivity and plasma immunoreactive beta-endorphin (ir-BEND) concentrations was examined in eight healthy Thoroughbred horses. Pain thresholds, ir-BEND concentrations, rectal temperature, heart rate, respiratory rate and pupil diameter were measured over a 24 hour period. Nociceptive sensitivity was determined using two objective measures of pain: the skin-twitch reflex latency and the hoof withdrawal reflex latency. Significant variation in both nociceptive thresholds and ir-BEND concentrations were noted over the 24 hour period, with elevated pain threshold...
Williams R, Du Plessis DH, Van Wyngaardt W.Group-reactive enzyme-linked immunosorbent assays (ELISAs) were developed to selectively detect antibodies to African horsesickness virus (AHSV) and equine encephalosis virus (EEV), 2 orbiviruses that infect equids. In indirect ELISA, guinea pig antisera to all known AHSV or EEV serotypes recognized immobilized AHSV serotype 3 or EEV Cascara, respectively. Antisera from naturally infected animals did not cross-react with their respective heterologous viruses. The ELISA was used in parallel with the complement fixation (CF) and agar gel immunodiffusion tests to detect antibodies in sera from an...
Burlacu GH, Voicu D, Voicu I, Nicolae M, Petrache E, Georgescu GH, Balan S.The present study focused on energy and protein metabolism in pregnant and lactating mares, including the suckling and weaned growing horses, in order to determine feed availability, as also the energy and protein requirements. The authors found that the feeding diets, consisting of alfalfa hay, oats and compounds, had different availability values in terms of energy and protein, according to animal physiological conditions and age. Thus, the pregnant mares utilized the metabolizable energy (ME) and digestible crude protein (DCP) intake in average proportions of 64.5 +/- 3.2%, 54.6 +/- 3.0%, r...
Corstvet RE, Gaunt SD, Karns PA, McBride JW, Battistini RA, Mauterer LA, Austin FW.An enzyme-linked immunosorbent assay (ELISA) was used to detect antigen in plasma and antibody in serum of 3 horses inoculated with Ehrlichia equi. Clinical signs, including rectal temperature, were correlated with the antigen and antibody detection. ELISA was very efficient in detection of serum antibody. Antigen detection using monoclonal antibodies to E. equi and ELISA should be considered as a diagnostic method.
Valberg S, Jönsson L, Lindholm A, Holmgren N.Six horses with a history of recurrent exertional rhabdomyolysis (RER) (Horses A-F) and 7 control horses performed a submaximal and later a near-maximal treadmill exercise test. Blood samples were obtained before, during and after exercise and muscle biopsies were taken before and after exercise. At rest, plasma aspartate aminotransferase (AST) activities in horses with RER were above 95% confidence intervals for control horses. During submaximal exercise, 3 horses with RER (A, B and C) had much greater increases in plasma AST, creatine kinase (CK) and myoglobin concentrations than did Horses ...
Bergentz SE.Jean Martin Charcot was the first to give a detailed description of intermittent claudication, and a correct interpretation of the mechanism behind the symptoms. He borrowed the name of the syndrome from the veterinarian literature, where it had been described to occur in horses, and caused by inflammatory changes in aorta at the origin of the large vessels to the extremities. The case presented by Charcot was a man with a traumatic pseudoaneurysm in his common iliac artery. He had in addition an arterio-enteric fistula, a condition which probably had not been described before.
Gift LJ, Gaughan EM, DeBowes RM, Pintchuk PA, Nickels FA, Foreman JH.Medical records of 11 adult horses with jejunal intussusception examined at 5 veterinary teaching hospitals between 1981 and 1991 were reviewed. Nine of 11 horses had signs of acute abdominal discomfort for < 24 hours, whereas 2 horses had a history of chronic signs. Five of 11 horses had an intraluminal or intramural mass associated with the jejunal intussusception. Two horses died or were euthanatized prior to surgery. Partial jejunal resection and jejunojejunal anastomosis were performed in 9 horses. One horse died during surgery and 2 were euthanatized prior to hospital discharge because o...
Back W, Barneveld A, van Weeren PR, van den Bogert AJ.Gait analysis plays a major role in the clinical evaluation of equine lameness. It is generally accepted that the clinician expresses the grade of lameness as a subjective score. In this study lameness was objectively assessed using a standardized transient lameness model, in which lameness was induced by intra-articular injection of bacterial endotoxin into the radiocarpal joint of ponies. Lameness was scored by an experienced clinician, and locomotion was recorded simultaneously using a CODA-3 apparatus. The obtained kinematic gait parameters correlated well with the clinical lameness score ...
Irvine CH, Alexander SL.We used our unique nonsurgical technique for collecting pituitary venous (pit) blood to study GnRH, FSH, and LH secretion patterns in midluteal phase mares. This method does not perturb endocrine function and allows continuous monitoring of GnRH and gonadotropin (Gn) secretion, determination of the amount of GnRH perfusing gonadotropes, and direct measurements of the amounts of Gn secreted. In a total of 80 h of 5-min sampling in four mares, eight Gn peaks occurred; however, more frequent sampling was needed to define secretory events precisely. Therefore, pit blood was collected continuously ...
Hunt RJ.Case records of 202 horses treated for laminitis were reviewed with the intent of determining the long-term outcome and correlating this with digital radiographic findings and with the degree of pain associated with the laminitis. At long-term follow-up 57 horses had returned to athletic soundness (Group 1), 20 horses were intermittently lame (Group 2), 19 horses had permanent severe lameness (Group 3), 97 were dead (Group 4), and 9 were lost to follow up. Using simple regression analysis, functional outcome did not correlate with the degree of rotation (R2 = 0.004) or the presence of distal d...
Leach DH.Cells of the intertubular horn of the stratum medium of the equine hoof wall are joined by three types of junctions. Desmosomes and gap junctions were present in all strata. Septate-like junctions and an intercellular line were seen in the distal stratum spinosum subsequent to extrusion of the contents of membrane-coating granules. At a later stage of keratinization, non-membrane-bound acid phosphatase reaction product appeared to leak into the intercellular space except into areas occupied by septate-like junctions and the intercellular line. It is proposed that the formation of septate-like ...
Step DL, Cummings JF, de Lahunta A, Valentine BA, Summers BA, Rowland PH, Mohammed HO, Eckerlin RH, Rebhun WC.A 9-year-old Quarter Horse mare was examined because of progressive weight loss, weakness, muscle atrophy and tremors, and behavioral change. Selenium and glutathione peroxidase assays, blood lead analysis, erythrocyte transketolase analysis, pseudorabies and Borrelia burgdorferi serology, electromyography, and CSF analysis were performed. Motor neuron degeneration was diagnosed by microscopic examination of neural tissues. The cause of the disease was not substantiated, but several possibilities were excluded via diagnostic testing. Diagnosis of motor neuron degeneration in horses may be made...
Jones JH, Lindstedt SL.Body size fundamentally affects maximal locomotor performance in mammals. Comparisons of performances of different-sized animals yield different results if made using relative, rather than absolute scales. Absolute speed may be a reasonable way to evaluate the locomotor performance of an animal that must escape predators in real time. However, comparisons of metabolic power in animals of different size can only be made meaningfully on a mass-specific basis. Numerous factors associated with the mechanics, energetics, and storage of elastic energy during locomotion change with body size, which r...
Colahan P, Lindsey E, Nunier C.The pressure exerted on a flat level surface by recently trimmed, unshod hoofs of the front limbs of 23 sound, adult horses was measured using pressure-sensitive film and a specially built cassette. The horses were tranquilized and stood with one foot on the 2.9-cm-thick cassette and the other on a block of equal height. The hoofs were observed for motion during the measurement, and the developed film was examined for improper alignment of the film or slipping of the hoof. The center of pressure was located using the method of weighted proportions of Barrey. This static measurement system with...
Hawkins JF, Schumacher JS, McClure SR, Light GS.Small intestinal incarceration through the lateral ligament of the urinary bladder was diagnosed in a 14-year-old, 569-kg, castrated Quarter Horse. The incarceration was corrected by ventral midline celiotomy. Approximately 70 cm of the middle portion of the jejunum was resected and end-to-end, single-layer anastomosis was performed. After surgery, the horse developed signs of adynamic ileus and lameness in the right forelimb. The horse developed laminitis in all 4 feet within 24 hours of surgery. The horse was euthanatized because of poor prognosis for survival. At necropsy, a 4.5-cm rent was...
Ratzlaff MH, Wilson PD, Hyde ML, Balch OK, Grant BD.Three methods were used simultaneously to determine the relationships between the vertical forces exerted on the hooves and the positions of the limbs and hooves at the times of peak vertical forces from 2 horses galloping on a track straightaway. Vertical forces were recorded from an instrumented shoe, fetlock joint motion was measured with an electrogoniometer and the angles of the carpus, fetlock and hoof were determined from slow-motion films. At hoof contact, the mean angles of the carpus and fetlock were 181-182 degrees and 199-206 degrees, respectively. Peak vertical forces on the heel ...
van Weeren PR, van den Bogert AJ, Back W, Bruin G, Barneveld A.A kinematic study was performed on a group of 8 Standardbred stallions. Recordings were done using a modified CODA-3 optoelectronic kinematic analysis system with the horses running on a treadmill at speeds of 6, 7, 8, or 9 m/s. Linear and temporal gait characteristics, joint angle diagrams and the trajectories of the hoof in a plane perpendicular to the direction of movement were studied. Two consecutive recording sessions were held at an age of 21-23 months, and a third was held 5 months later after an intensive training period. Joint angle diagrams appeared to show a similar pattern for all...
Uzal FA, Robles CA.Mal seco is a grass sickness-like syndrome of horses which has mainly been observed in Patagonia, Argentina, although some reports indicate that the disease may exist in other Argentinian provinces and in the south of Chile. The aetiology of mal seco remains unknown but the disease seems to be restricted to animals grazing on natural pastures and not receiving supplementary feeding. Mal seco is clinically characterized by total or partial bowel stasis and the main findings at post-mortem examination are almost exclusively restricted to the bowel. The most striking histopathological changes fou...
Clayton HM.This study was designed to test the hypothesis that there is no significant difference in selected temporal and linear stride variables of the extended canter in horses bred and trained for dressage or racing. Nine advanced-level dressage horses and 7 Thoroughbred racehorses were filmed at a frame rate of 200 Hz at an extended canter on a sand track. Two strides were recorded per trial, and each horse performed 6 or 7 trials. Temporal and linear data were determined from the films, and descriptive statistics (mean, SD) were calculated. Strides were selected for analysis on the basis of having ...
Pethick DW, Rose RJ, Bryden WL, Gooden JM.Nutrient uptake by the hindlimb was investigated utilising the arteriovenous difference technique in 5 Thoroughbred horses fed to maintenance a diet of 100% roughage or 52% oat grain and 48% roughage. Arterial blood was obtained from a catheter inserted into the carotid artery while venous blood was simultaneously collected from a catheter placed into the iliac vein via the medial saphenous vein. The arteriovenous difference for glucose was significant and represented a mean extraction of 10 +/- 1% with no effect of diet. If fully oxidised, glucose uptake (corrected for lactate and pyruvate ar...
Herzog B, Lindner A, Sommer H.To compare the career profiles of thoroughbred racehorses in Germany in different decades all horses which raced for the last time in the years 1966/67, 1976/77 and 1986/87 were selected from the annual report of the German Thoroughbred Racing Association. The number of racing horses increased within decades while the percentage of the horses which raced for the last time was equal in all years. It amounted yearly to about 30%. Most of the horses finished racing at three and four years of age. In 1966, 1967, 1976 and 1977 more than 50% of the horses began their career at the age of two years, ...
Jehle MC, Biermann NM, Haltmayer E.This retrospective case series aims to highlight the advantages and disadvantages of different treatment options for sinus disease in horses, with a special focus on surgical approaches. The medical records of 25 horses with sinusitis which presented to the equine hospital, Vetmeduni Vienna, between August 2020 and January 2022 were analysed. In 11 cases, conservative treatment by the transnasal endoscopic lavage of the affected sinuses through the sinonasal channel or through a developed, pre-existing sinonasal fistula was performed. In the remaining 14 cases, openings into the sinus for subs...
Forsman C, Jonsson BH, Lindskog S.The 250 MHz 1H-NMR spectrum of horse carbonic anhydrase I (or B) (carbonate hydro-lyase, EC 4.2.1.1) was measured as a function of pH under various conditions. Eight resonances corresponding to histidine C-2 protons and four resonances corresponding to histidine C-4 protons were identified and assigned to individual histidine residues in the enzyme molecule. Substantial similarities between horse and human carbonic anhydrases I were demonstrated. While the human enzyme has three titratable histidine residues in its active site, the horse enzyme has only two, His-67 in the human enzyme being re...
Pool-Anderson K, Raub RH, Warren JA.Six pairs of full-sibling Quarter Horse foals were produced by non-surgical embryo transfer and immediate rebreeding of donor mares. Each pair of donor/recipient mares consisted of one multiparous (donor) and one nulliparous (recipient) mare of similar body type and size. Milk yield was determined within 2 d of 8, 15, 22, 29 d (early lactation); 45, 60 d (midlactation); and 90, 120 d (late lactation) postpartum by the weigh-suckle-weigh method. On the following day, milk samples were collected, and foals were weighed and measured for wither height, heart girth, metacarpal length, metatarsal le...
Hagedorn HW, Schulz R.The use of diuretics in horses subject to doping control is prohibited. Thus, a sensitive screening procedure is required to identify the chemically different diuretics. We communicate here a method to detect three commonly employed acidic diuretics: bumetanide, ethacrynic acid, and furosemide. A liquid-liquid extraction on Extrelut 3 was performed at weak acidic and basic conditions using ethyl acetate as organic solvent. For analysis by GC, the diuretics were methylated on-column in the presence of MSTFA/TMAH, avoiding the commonly employed highly toxic derivatizing agent methyl iodide. For ...
Sparks HD, Nixon AJ, Bogenrief DS.3 horses were referred for treatment of subchondral cystic lesions of 1 or both medial femoral condyles. Results: All horses had clinically apparent lameness confirmed to be due to a radiographically evident subchondral cystic lesion of the medial femoral condyle with a large articular component (> 15 mm) and shallow subchondral depth (< 10 mm). Arthroscopic assessment of affected cartilage revealed undulating cartilage with a relatively smooth surface and extensive residual perimeter attachment. Results: Resorbable polydioxanone pins were used arthroscopically to reattach the cartilage ...
Kilcoyne I, Nieto JE, Knych HK, Dechant JE.OBJECTIVE To determine the maximum concentration (Cmax) of amikacin and time to Cmax (Tmax) in the distal interphalangeal (DIP) joint in horses after IV regional limb perfusion (IVRLP) by use of the cephalic vein. ANIMALS 9 adult horses. PROCEDURES Horses were sedated and restrained in a standing position and then subjected to IVRLP (2 g of amikacin sulfate diluted to 60 mL with saline [0.9% NaCl] solution) by use of the cephalic vein. A pneumatic tourniquet was placed 10 cm proximal to the accessory carpal bone. Perfusate was instilled with a peristaltic pump over a 3-minute period. Synovial ...
Younkin JT, Santschi EM, Kukanich B, Lubbers BV, Warner M.Penicillin is administered intravenously (IV) or intramuscularly (IM) to horses for the prevention and treatment of infections, and both routes have disadvantages. To minimize these shortcomings, a 24-hr hybrid administration protocol (HPP) was developed. Our objective was to determine penicillin plasma concentrations in horses administered via HPP. Venous blood was collected from seven healthy horses administered IV potassium penicillin G at 0 and 6 hr and IM procaine penicillin G at 12 hr. Blood was collected at 2-hr intervals from 0 to 20 hr and at 24 hr. Plasma penicillin concentration...
Fenger CK, Bertone JJ, Biller D, Merryman J.Generalized medullary infarction of the long bones was diagnosed in a 12-year-old Tennessee Walking Horse mare. The mare was referred after a 6-week course of shifting weight on her hind limbs, and kicking. Physical examination revealed mild stifle joint distention and withdrawal reactions to digital pressure over the long bones. Radiography revealed patchy areas of medullary sclerosis in the distal portion of each femur and proximal portion of each tibia. A full-thickness cortical and cancellous tibial biopsy revealed infarcted bone marrow, with cortical and periosteal osteonecrosis. The caus...
MacLeod JN, Kalbfleisch TS.The first equine reference genome was completed in 2007 and published in 2009. This major accomplishment has enabled equine science to advance in ways that broadly parallel the transformative impact that genomics has had on many animal species including humans. A conceptual overview of reference genomes, genome annotation, and the major implications for equine science is presented. The relationship between genomic sequencing and the accelerating application of precision P4 medicine is discussed in the context of human and equine patients. Emergent technologies built on the foundation of genomi...
Province CA, Amann RP, Pickett BW, Squires EL.Two experiments were conducted to evaluate the effects of six extenders and three glycerol levels on the motility of sperm stored at 5 degrees C. Using a split-ejaculated design, semen from 10 dogs and 12 stallions was extended with egg-yolk-tris (EYT), egg-yolk-bicarbonate (EGB), Beltsville F-3 (BF-3), Cornell University (CUE), caprogen (CAP) and heated skim milk (SM) extenders. After cooling to 5 degrees C, additional extender containing 0% to 12% glycerol was added to provide a final concentration of 0%, 3% or 6% glycerol. Regardless of glycerol level, a higher (P<0.05) percentage of can...
Zoll WM, Prakoso D, Dark M, Liu J, Stockdale-Walden H, Long MT.Eosinophils within the central nervous system are abnormal and are usually associated with fungal or parasitic infections in horses. Causative agents include Halicephalobus gingivalis, Sarcocystis neurona, and Neospora hughesi. Confirmation of these organisms via specific testing is typically not performed, and final diagnoses are often presumptive. With molecular technology, many of these organisms can now be confirmed. This is important for emerging and zoonotic pathogens, including Angiostrongylus cantonensis, an emerging parasite of interest in the southeastern United States. We retrospect...
Curnow B, Rich AF, Ireland J, Correa DC, Dunn J, Jenkins D, Carslake H, Ressel L.Although the equine sarcoid is the most common skin neoplasm in domesticated horses, histopathological characteristics have not previously been evaluated for association with recurrence. The aim of this retrospective cohort study was to investigate clinical and histopathological features of excised equine sarcoids and to evaluate their association with recurrence at the original surgical site and at new sites. Clinical records and excisional biopsies from 106 equine sarcoids from 64 horses referred to Leahurst Equine Hospital, University of Liverpool, between March 2010 and February 2015 were ...
Srivastava SK, Barnum DA.The ability of either formalin-treated or heat-inactivated whole Streptococcus equi cell vaccines or partially purified M-protein of S. equi to give rise to protective antibody levels was studied in Standardbred foals by serological means. Two commercial preparations, i.e. a beta-propiolactone killed whole S. equi cell bacterin and a cell-free extract of S. equi cells were included in the study. The mean passive hemagglutination antibody titers (10 X log2) in sera of foals given either four doses of formalin-treated whole cell vaccine or an initial dose of formalin-treated followed by three do...
Jungeblut CW.1. A flocculation reaction has been described which occurs between alcoholic extracts of pneumococci and antipneumococcus serum. 2. The reaction appears to be species-specific. It is not strictly type-specific, as slight or moderate cross-reactions occurred between Type I serums and Type II and Type III extracts. 3. The flocculating power of the serum from five horses undergoing immunization with pneumococcus, Type I, did not develop to any extent before the end of the 4th or 5th month. 4. In the case of two of these horses in which it was possible to carry out parallel tests on a larger numbe...
Johnston JK, Freeman DE, Gillette D, Soma LR.Sheets of mucosa from the jejunum of healthy horses were mounted in incubation chambers and bathed with Krebs-Ringer bicarbonate solution. Changes in tissue function and histologic appearance were compared after the following conditions: (1) control conditions for 30 minutes with 95% O2/5% CO2 in the gas phase; (2) same conditions as control, except incubation with superoxide dismutase (300 U/ml) during the last 18 minutes; (3) anoxia for 15 minutes with 95% N2/5% CO2, followed by reoxygenation for 15 minutes; (4) same conditions as 3, except incubation with superoxide dismutase during reoxyge...
Camargo Ferreira J, Linhares Boakari Y, Sousa Rocha N, Saules Ignácio F, Barbosa da Costa G, de Meira C.The present study characterized the luteal status and the dynamic of the conceptus during the first 20 days of gestation in mares with different ages and degrees of endometrial degeneration. Total area of the corpus luteum (CL), luteal vascularity, CL area with blood signals, progesterone concentrations (P4), embryonic vesicle diameter, number of embryonic location changes, embryonic fixation position and uterine contractility were evaluated. In Experiment 1, mares ≤6 years of age (Young group, 5.6 ± 0.2 years, n = 7 mares) and mares ≥15 years of age (Old group, 17.2 ± 0.9 yea...
Peham C, Schobesberger H.Knowledge of load effects is crucial for the understanding of the aetiology and pathogenesis of equine back problems. Objective: To investigate different load scenarios of the equine back, such as being ridden or increased muscle tone, using biomechanical simulations. Methods: Kinetic and kinematic data of 15 sound horses and the electromyelograph of their long back muscles were recorded. A biomechanical simulation model was used for simulations under different biomechanical scenarios (ridden/unridden, localised increased stiffness) using ADAMS. Results: The vertical forces acting through a ri...
Hébert L, Rincé I, Sanna C, Laugier C, Rincé A, Petry S.The genus Taylorella is composed of two species: (i) Taylorella equigenitalis, the causative agent of CEM, a venereally transmitted infection of Equidae and (ii) Taylorella asinigenitalis, a closely related species considered to be nonpathogenic, although experimental infection of mares with this bacterium resulted in clinical signs of vaginitis, cervicitis or endometritis. Currently, there is a need for an alternative host model to further study the taylorellae species. In this context, we explored Galleria mellonella larvae as potential alternative model hosts for taylorellae. Our results sh...
Erichsen C, Eksell P, Widström C, Berger M, Holm KR, Johnston C.The sacroiliac region in 33 clinically normal riding horses was examined with scintigraphy to determine the normal scintigraphic appearance, to evaluate a semiquantitative method used to calculate a sacroiliac joint (SI joint) ratio, and to identify factors that affect the scintigraphic appearance of the pelvis. The scintigraphic examination included dorsal views of each SI joint region and one lateral view of the urinary bladder. Two predefined areas (the SI joint and the area between the tuber sacrale and the SI joint) were evaluated subjectively by comparing the intensity in each area to th...