Regression analysis is a statistical method used to examine the relationship between variables, often employed to predict outcomes or understand associations in equine studies. In the context of horses, regression analysis can be applied to a variety of research areas, including performance metrics, health parameters, and genetic traits. By analyzing data, researchers can identify patterns or correlations that may inform breeding decisions, training regimens, or health interventions. This page compiles peer-reviewed research studies and scholarly articles that explore the application of regression analysis in equine research, focusing on methodologies, findings, and implications for horse management and care.
Sampson SN, Tucker RL, Bayly WM.We evaluated the relationships of heart score (HS) and echocardiographic measures to maximal oxygen consumption (VO2max), maximal cardiac output (Qmax), and maximal stroke volume (SVmax). Six fit, mature Thoroughbred horses weighing (mean +/- s.e.) 487 +/- 11 kg were run 4 times on an inclined (10%) treadmill. Each run consisted of a 3 min warm-up at 4 m/s followed by completion of an incremental exercise test in which each horse ran until VO2max was reached. Arterial and mixed venous blood was collected to determine arteriovenous oxygen content difference C(a-v)O2[ in the last 15 s of exercis...
Bowers JR, Slocombe RF.Eight horses were exercised at speeds to produce 80% of maximal heart rates, on 4 occasions using a randomised block design, and girthed at tensions of approximately 5, 10, 15 or 20 kg using a standard canvas girth attached to a racing saddle. Tension was recorded continuously using an in-line load cell connected to a physiograph. Horses ran until fatigued on a treadmill inclined at 10% slope. Tensions were measured at peak inhalation (T/inh) and exhalation (T/exh), recorded at rest (rest) and during exercise (ex). Data were analysed by ANOVA and, in addition, least squares linear regression w...
Hanzawa K, Kai M, Hiraga A, Watanabe S.We examined the relationship in horses between osmotic fragility of erythrocytes (OFE) measured as the red cell haemolysis rates (HLR) in 0.56% NaCl and certain physiological characters. Animals were exercised on a treadmill: warmed up at 30% VO2max for 5 min or at 105% VO2max for 1 min, given an exercise test at 80 or 105% VO2max until fatigued, and then cooled down. The pH and temperature of the blood had a significant correlation for the HLR: r = 0.93 and 0.92 (P < 0.01) on arterial and mixed venous blood, respectively. In multiple regression analysis, heart rate and packed cell volume s...
Kohn CW, Hinchcliff KW, McKeever KH.Six healthy Thoroughbred mares were trained to run on a high-speed treadmill and were conditioned for approximately 5 weeks. Each horse performed 6 identical standardised exercise tests (SET) 5 to 7 days apart. Each SET was performed under different ambient laboratory conditions: low temperature/low humidity (LL) 20.2 degrees +/- 0.6 degree C, 53.6 +/- 4.1%; low temperature/high humidity (LH) 19.7 +/- 0.6 degrees C, 86.7 +/- 4.2%; medium temperature/low humidity (ML) 24.6 +/- 0.2 degrees C, 58.7 +/- 3.7%; medium temperature/high humidity (MH) 24.7 +/- 0.3 degrees C, 87.5 +/- 1.4%; high tempera...
Kobayashi M, Kuribara K, Amada A.The purpose of this investigation was to study, under field conditions, the usefulness of an incremental exercise test to measure V200 (running velocity [V] at heart rate HR[ of 200 beats/min) for evaluation of training effects in the young Thoroughbred. Five to 112 two-year-old Thoroughbreds were used over 4 years to investigate the correlation between HR and V, the influence of the track and rider's weight to V200, reproducibility of V200 and the changes of V200 as training progresses. The high correlation coefficient between HR and V, and V200 were obtained in horses that exercised smoothly...
Kronfeld DS, Ferrante PL, Taylor LE, Tiegs W.Increases in blood [H+] and lactic acid [La-] attend fatigue. We applied Stewart's physiological model of acid-base status and simple regressions to assess the importance of independent variables and [La-] on [H+] during repeated sprints. Eight well-conditioned Arabians performed 9 sprints. Plasma from jugular vein samples was analysed for pH, PCO2, Na+, K+ and Cl-. Plasma [La-] was calculated from blood [La-], plasma [H+] from pH, SID from Na+, K+, Cl- and La-, Atot from pH, PCO2 and SID. Peaks for SID, PCO2 and [H+] were reached at sprint 1, -2 and -3, respectively. At sprint 3, the 5.7 nmol...
Couroucé A, Corde R, Valette JP, Cassiat G, Hodgson DR, Rose RJ.The purpose of this study was to determine the optimal treadmill slope for trotters to produce the same heart rate and blood lactate responses as on the track during a standardized exercise test. Nine 2-year-old French trotters performed exercise tests on a training track and on a treadmill set at an incline of 0, 2 or 4%. For all horses, track testing was performed on day 1 and then on the treadmill according to a Latin-square design. The track test utilized three steps each of 3 min at speeds of 470, 530, 590 m/min and the same speeds were used on the treadmill. Derived physiological variabl...
Hoffman RM, Lawrence LA, Kronfeld DS, Cooper WL, Sklan DJ, Dascanio JJ, Harris PA.Hydrolyzable carbohydrate intake in horse diets may become excessive when rapidly growing pastures are supplemented with grain-based concentrates. The substitution of fat and fiber for hydrolyzable carbohydrate in concentrates has been explored in exercising horses but not in young, growing horses. Our objective was to compare bone development in foals that were fed pasture and concentrates rich in sugar and starch (corn, molasses) or fat and fiber (corn oil, beet pulp, soybean hulls, oat straw). Forty foals were examined, 20 each in 1994 and 1995. In each year, 10 mares and their foals were f...
Nequin LG, King SS, Roser JF, Soderstrom BL, Carnevale EM, Neumann KR.The reproductive activity of light horse mares (n=12) was monitored each day from 3 September until 29 January, or until the mares entered anoestrus, by behaviour evaluation, ultrasonography and blood sampling. Follicles, corpora lutea and ovulation, as well as oestradiol, progesterone, and LH and FSH concentrations, were analysed to determine a reproductive profile for the transition into anoestrus. The results of the present study indicate that light horse mares progress through four phases during the autumn transition into anoestrus: (i) normal cycles; (ii) aberrant cycles; (iii) anovulatio...
Greaves HE, Porter MB, Sharp DC.Long-term ovariectomized Pony mares were treated with oestradiol (0.2-5.0 mg; i.m.) at 12 h intervals for 10 days. Blood samples were collected by jugular venepuncture three times a day throughout the experiment and additional blood samples were collected at 15 min intervals for 12 h on days 0 and 10 (sampling periods 1 and 2, respectively). There were significant effects of oestradiol treatment (P < 0.05) and oestradiol treatment x day (P < 0.0001) on the mean LH concentrations each day. Regression analysis of LH time trends each day indicates that there is heterogeneity (P < 0.001) ...
Fubini SL, Erb HN, Freeman KP, Todhunter RJ.Between July 1, 1983 and December 31, 1990, risk factors were determined for all horses with joint disease presented to a referral center, of being discharged, of ever becoming sound, or of being alive at 3 mo follow-up. Logistic multiple-regression models were done separately for foals (< or = 4 mo), yearlings (> 4-24 mo) and racing or nonracing adult horses (> 24 mo). The breakdown in this study was 53 foals, 87 yearlings, 141 nonracing adults, and 226 racing adults. Thirty-one foals (58%), 68 yearlings (78%), 119 non-racing adults (84%), and 213 racing adults (94%) were discharged. Foals wi...
Cripps PJ, Eustace RA.The significance of clinical and radiological parameters as prognostic indicators for laminitis, 'founder' and 'sinking syndrome' was studied using case records of 216 horses and ponies. Five animals were destroyed without treatment and were not included in the results of the study. One hundred and sixty-two (77%) animals returned to athletic soundness; 7 animals (3%) did not regain full athletic function, 42 animals (20%) died or were destroyed. Cases were assigned to 4 groups on the basis of initial clinical examination alone. These groups were laminitis, acute founder, 'sinker' and chronic ...
Luescher UA, McKeown DB, Dean H.A researcher-administered survey study was performed involving 769 horses from 32 Thoroughbred, Standardbred, and pleasure horse stables in southwestern Ontario. Data were gathered on individuals (breed, age, and sex) and at the stable level (housing, management). The effects of these factors on cribbing, stall-walking, weaving, stall-kicking, tongue playing, and pawing were assessed by unconditional analysis (Chi-square, t test) and conditionally using stepwise logistic regression. Individual level factors had significant effects on most compulsive behaviours. Some stable level factors, in mo...
Gross DK, Morley PS, Hinchcliff KW, Wittum TE.To determine the effect of furosemide on performance of Thoroughbreds racing on dirt surfaces at tracks in the United States and Canada. Methods: Cross-sectional study. Methods: All Thoroughbreds (n = 22,589) that finished a race on dirt surfaces at tracks in the United States and Canada between June 28 and July 13, 1997 in jurisdictions that allowed the use of furosemide. Methods: Race records were analyzed by use of multivariable ANOVA procedures and logistic regression analyses to determine the effect of furosemide on estimated 6-furlong race time, estimated racing speed, race earnings, and...
Chiappe A, Gonzalez G, Fradinger E, Iorio G, Ferretti JL, Zanchetta J.In this study, we assessed the potential value of free serum osteocalcin or bone gla protein (BGP), the most abundant non collagenous matrix protein found in bone and dentin, to reflect changes of bone turnover in thoroughbred horses. Levels of osteocalcin were analyzed in serum samples of 54 clinically normal animals divided into three groups (A, B, C) according to age: 8, 16-18 and 24-36 months, in order to determine the standard for young horses of different age and sex. Serum BGP was measured by an in-house developed double antibody radioimmunoassay using bovine antigen. The mean BGP level...
Toews AR, Bailey JV, Townsend HG, Barber SM.To examine the amount of heat generated in equine cortical bone by a 6.2-mm drill, using low- and high-speed and controlled feed rate drilling. Methods: 10 metacarpal bones harvested from five 2-year-old draft-type horses. Methods: Drilling on metacarpal bones was done using a machine shop mill with which the feed rate and drill speed could be precisely controlled. Bones were drilled, using 6 combinations of feed rate (1, 2, and 3 mm advance/s) and drill speed (317 and 1,242 revolutions/min [rpm], with maximal temperatures recorded by thermocouples placed 1, 1.5, and 2 mm from the drill. Maxim...
Rodriguez MH, Chavez B, Hernandez-Avila JE, Orozco A, Arredondo-Jimenez JI.Light and scanning electron microscopy were used to compare the eggs of Anopheles vestitipennis Dyar & Knab females collected from human and animal baits in 9 villages of southern Mexico. An. vestitipennis eggs are boat-shaped, with lateral floats extending the length of the egg. Both the deck and dorsal surface are covered with hexagonal and pentagonal chorionic cells that contain round tubercles in the cell field. Crowns that enclose 3-5 lobed tubercles are present at both egg poles. By light microscopy, the mean length/width ratio of eggs of females caught at human bait were statistical...
Thomas HL, Zaruby JF, Smith CL, Livesey MA.Castration of horses is considered a common and routine surgical procedure, but the potential for complications is high. By far the most serious of these is eventration. The objectives of this study were to determine the long-term survival of horses undergoing surgical treatment of indirect (1) inguinal eventration of the small intestine following castration, and to identify prognostic indicators for survival. The case records of 18 horses undergoing surgical treatment of postcastration eventration (PCE) between 1985 and 1995 were reviewed. Follow-up information was obtained by telephone inter...
Sorrell-Raschi LA, Tomasic M.To evaluate the accuracy of 3 automated methods of determining Hct and hemoglobin (Hb) concentration, compared with manual methods. Animals-22 clinically normal adult horses of various breeds. Methods: A blood sample was obtained from each horse. Six dilutions (representing Hct of 0, 10, 20, 40, 60, or 70%) were prepared from each sample and analyzed, using 1 of 2 blood gas analyzers or a hemoximeter (for automated determinations) or the Wintrobe macrohematocrit and cyanmethemoglobin methods (for manual determinations). Regression analysis was used to determine mean slope relationships between...
Dyke TM, Sams RA, Hinchcliff KW.To determine the effects of acute exercise on hepatic blood flow by studying hepatic clearance of bromsulphalein for several submaximal exercise intensities. Methods: 8 adult Standardbred mares. Methods: Horses were subjected to 4 submaximal exercise intensities (resting and 40, 60, and 80% maximal oxygen consumption). After horses had been running at the required treadmill speed for 1 minute, bromsulphalein (BSP; 5 mg/kg of body weight, IV) was administered during a 45- to 60-second period, and horses continued at the desired speed for an additional 15 minutes. Blood samples were collected at...
Galisteo AM, Cano MR, Morales JL, Vivo J, Miró F.The influence of speed and height at the withers on some biokinematic stride parameters (linear, temporal and angular) was measured in 15 Spanish Thoroughbreds (Andalusian Purebred) trotted hand-led along a track; analysis was made of the correlation between speed and height at the withers and of some biokinematic parameters of equine locomotion. Both height at the withers and speed were positively and significantly correlated to the linear parameters examined. Temporal parameters did not reveal a significant correlation with the height at the withers. The correlations with the angular paramet...
Hullinger PJ, Wilson WD, Rossitto PV, Patton JF, Thurmond MC, MacLachlan NJ.To determine rate of decay of passively acquired antibodies in Standardbred foals on a farm with a high seroprevalence to equine arteritis virus (EAV) and to determine whether vertical or horizontal transmission of the virus was responsible for infection on the farm. Methods: Repeated-measures study. Methods: 46 Standardbred horses (15 brood mares and their foals, 5 stallions, and 11 young horses). Methods: Serum samples obtained from horses on the farm were evaluated by serum neutralization and western immunoblot analysis to detect EAV-specific antibodies. The half-life of passively acquired ...
Doherr MG, Carpenter TE, Hanson KM, Wilson WD, Gardner IA.A case-control study was designed using equine medical records from the UC Davis Veterinary Medical Teaching Hospital (VMTH) and data derived through a mailed survey. The objective was to evaluate the associations between horse demographics, horse-management factors, and equine Corynebacterium pseudotuberculosis infection in California. Horses admitted to the VMTH between July 1 1992 and June 30 1994 served as the study base for case identification and simple random sampling of 800 controls. A questionnaire was mailed to the owners of all horses enrolled in the study to collect data on demogra...
Constable PD, Hinchcliff KW, Muir WW.To compare the accuracy of anion gap (AG) and strong ion gap (SIG) for predicting unmeasured strong ion concentration in plasma and serum from horses. Methods: 6 well-trained Standardbred horses undergoing high-intensity exercise (experimental study) and 78 horses and ponies that underwent i.v. administration of lactic acid or endotoxin, and endurance, submaximal, or high-intensity exercise. Methods: Anion gap was calculated as AG = (Na+ + K+) - (Cl- + HCO3-), and SIG was calculated, using the simplified strong ion model, whereby SIG (mEq/L) = 2.24 x total protein (g/dl)/(1 + 10(6.65-pH)) - AG...
Weber Polack E, King JM, Cummings JF, de Lahunta A, Divers TJ, Mohammed HO.The mean number of motor neurons was assessed in the C7 spinal cord segment of 5 EMND and 5 control horses. Mean number per section in EMND horses was reduced significantly (P<0.001). The mean neuronal loss was estimated at 31%. Each of the 5 affected horses had a mean neuronal count below the 95% confidence interval for control horses. The statistically significant difference between the 2 groups was consistent in the cranial, middle and caudal thirds of the C7 segment (P<0.001). The results of regression analysis indicated an association between neuronal reduction in EMND horses and th...
Gayle JM, Cohen ND, Chaffin MK.In order to identify variables obtained at admission that could be used to predict survival in septicemic foals, medical records of 65 foals diagnosed with septicemia were reviewed. Initially, variables were analyzed independently (univariate analysis) for association with survival. Of the physical examination and historical data examined using univariate analysis, the ability to stand at admission, respiratory rate > or = 60 breaths per minute (bpm), and normal-appearing mucous membranes were significantly associated with survival. Foals with history of induced parturition were significant...
Vaidyanathan R, Edman JD.To estimate human exposure to potential vectors of eastern equine encephalomyelitis (EEE) virus, we compared collections of putative EEE virus vectors from human biting collections with collections from CDC, AB (American Biophysics), and New Jersey light traps and resting boxes in enzootic/epidemic foci of EEE virus in southeastern Massachusetts. Human biting collections caught significantly more host-seeking females than resting boxes or unbaited light traps (P < 0.05). Regression analysis of human biting collections to AB traps supplemented with CO2 could predict 60-70% of the actual human b...
de la Rúa-Domènech R, Mohammed HO, Cummings JF, Divers TJ, de Lahunta A, Summers BA.To identify intrinsic, management, nutritional, and environmental risk factors associated with equine motor neuron disease (EMND) and to determine whether epidemiologic evidence supports oxidative stress as a risk factor for developing EMND. Methods: Case-control study. Methods: 87 horses with EMND and 259 control horses. Methods: Information concerning each horse's history of exposure to multiple environmental factors prior to developing EMND was obtained by means of a questionnaire or personal interview. Exposure histories of horses with EMND and control horses were compared, and the associa...
Sams RA, Gerken DF, Dyke TM, Reed SM, Ashcraft SM.Cimetidine was administered intravenously and by the intragastric route to six mares at a dose of 4.0 mg/kg of body weight (bw). Specific and sensitive high performance liquid chromatographic methods for the determination of cimetidine in horse plasma and urine and cimetidine sulfoxide in urine are described. Plasma cimetidine concentration vs. time data were analysed by non-linear least squares regression analysis to determine pharmacokinetic parameter estimates. The median (range) plasma clearance (Cl) was 8.20 (4.96-10.2) mL/min.kg of body weight, that of the steady-state volume of distribu...
Barwick RS, Mohammed HO, McDonough PL, White ME.To determine and quantify risk factors associated with exposure of horses to the following serovars of Leptospira interrogans: pomona, autumnalis, and bratislava. Methods: 2,551 horses were randomly selected from a target population during the period of May 1991 to August 1993. Methods: Blood was collected from the horses and tested for antibodies to serovars, using the microscopic agglutination test. A titer > or = 1:100 indicated seropositivity. Information was collected on each horse, its environment, and each farm's management practices. Logistic regression analysis was used to develop a m...
Dhand NK, Sergeant ES.The aim of this preliminary study was to estimate the proportions of seropositive horses on infected premises (IPs) in order to assess the attack risk of the disease. Logistic regression analyses were conducted to evaluate the differences in attack risks between enterprise sizes and predefined spatial clusters/regions. The average attack risk experienced during the outbreak was 96.88% (median 100%), but it differed according to the size of the enterprise and other geographic and demographic conditions. The highest attack risks were observed in the Dubbo cluster/region and the lowest in the Nar...
de la Rúa-Domènech R, Mohammed HO, Atwill ER, Cummings JF, Divers TJ, Summers BA, deLahunta A, Jackson C.To examine the regional variations in the distribution of equine motor neuron disease (EMND) in the United States and the factors that might explain those variations. Methods: Cluster investigation and case-control study. Methods: The study population consisted of 97 horses with histopathologically confirmed EMND and 698 controls with diagnosis of other spinal cord disorders at 21 US veterinary teaching hospitals participating in the Veterinary Medical Data Base. Methods: The total horse population of the United States was divided into 21 regions, and the regional incidence rates of EMND from ...
Kamr AM, Dembek KA, Gilsenan W, Bozorgmanesh R, Hassan HY, Rosol TJ, Toribio RE.Hypocalcemia is a common finding in critically ill equine patients. Parathyroid hormone (PTH) helps to maintain calcium homeostasis in hypocalcemic patients by promoting renal calcium reabsorption and bone resorption. Increased serum PTH concentrations have been reported in critically ill people and animals, including horses and foals. It is unknown whether increased secretion of PTH is associated with markers of bone turnover in hospitalized foals. The goals of this study were to measure markers of bone resorption (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteoca...
Scudamore CL, Pemberton AD, Miller HR, McDonnell AM, Thomson SR, Dawson A, Watson ED.An enzyme linked immunosorbent assay (ELISA) was developed and used to estimate the concentrations of the serine proteinase inhibitor, alpha-1 proteinase inhibitor (API), in uterine flushings recovered from mares at different stages of the oestrous cycle and before and after the induction of experimental endometritis. There was a significant increase in the concentrations of API and albumin relative to total protein in flushings recovered during oestrus compared with dioestrus but no difference was observed in the concentrations of these proteins relative to total protein before and after the ...
Kamm JL, Bramlage LR, Schnabel LV, Ruggles AJ, Embertson RM, Hopper SA.Analysis was performed to examine a method for refining the preoperative prognosis for horses that had surgery to remove apical fractures of the proximal sesamoid bones (PSBs). Objective: To determine if: 1) there was a difference in size or configuration of apical fractures between the different anatomical locations of the PSBs, which have been shown to affect the prognosis; and 2) the size or configuration could predict the prognosis for racehorses with these fractures. Methods: The study included 110 weanlings and yearlings and 56 training racehorses that underwent surgery to remove apical ...
Weaver BM, Webb AI.The halothane muscle/gas partition coefficients at 37 degrees C for 26 samples of eight different muscles from four horses were found to depend significantly on the fat content of the muscle sample with a regression coefficient of 1.913 (SEM 0.109) per per cent ether-extractable fat content. The blood/gas partition coefficients in 24 horses showed a significant dependence on plasma triglyceride concentration (regression coefficient 0.00084 (SEM 0.00033) per mg dl-1), an insignificant positive dependence on plasma free and total cholesterol concentration and, in a multiple regression analysis, ...
Lescun TB, Hoffseth K, Yang HT, Hansma PK, Kopeikin HS, Chandrasekar S.To compare results obtained with a handheld reference point indentation instrument for bone material strength index (BMSi) measurements in the equine third metacarpal bone for various testing conditions. Methods: 24 third metacarpal bones. Methods: Third metacarpal bones from both forelimbs of 12 horses were obtained. The dorsal surface of each bone was divided into 6 testing regions. In vivo and ex vivo measurements of BMSi were obtained through the skin and on exposed bone, respectively, to determine effects of each testing condition. Difference plots were used to assess agreement between BM...
Curtis GC, Grove-White D, Ellis RN, Argo CM.Standard and modified measuring sticks were used to record height at the withers and a 'non-contact' laser was used to measure withers and loin heights. Sixty horses and ponies, ranging in height (115 to 155 cm) and body condition score (BCS) (moderate to obese) were measured by each method at 10-minute intervals for 40 minutes. Measurement series were repeated over three successive days. Unique regression models were constructed for method-specific data. Coefficients of variation were similar for stick and laser methods (0.002 to 0.004 per cent). Models were not influenced by day of measureme...
Airway obstruction is the main trait of severe equine asthma that affects respiratory function and elicits detrimental effects on clinical presentation. Only few and underpowered clinical studies have investigated the impact of improvement in lung function induced by bronchodilators on the clinical signs of asthma-affected horses. Objective: To identify the minimal important difference (MID) in lung function elicited by bronchodilator leading to a meaningful improvement in clinical signs. Methods: Pairwise meta-analysis and meta-regression analysis. Methods: Literature searches were performed ...
Broyles AH, Embertson RM, Brett Woodie J, Machado V.There is persistent concern among some trainers, owners and veterinarians regarding the effect of preoperative laryngeal function grade on the outcome of laryngoplasty and ventriculocordectomy (LPVC). Objective: To determine the effect of laryngeal function grade prior to LPVC on postoperative performance. Methods: Retrospective case-series. Methods: Medical and race records of Thoroughbred racehorses diagnosed with recurrent laryngeal neuropathy (RLN) and treated with LPVC between 1998 and 2013 were reviewed. Horses were placed into three groups based on preoperative laryngeal function grade ...
Ribeiro RM, Ribeiro DDSF, Cota LO, Carvalho AM, Gobesso AAO, Faleiros RR.This study aimed to compare the use of enzymatic colorimetry and Friedewald's formula for the determination of LDL in horses. A total of 260 samples were used. Direct analysis was performed to determine low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol, triglycerides (TG), and total cholesterol (TC). The LDL level was calculated using the Friedewald equation (LDL= TC-HDL-TG/5). The correlations between the direct LDL analysis and the LDL calculated using the Friedewald formula were determined by Pearson's tests, and the coefficient of determination was also obtained by ...
Dziezyc J, Taylor L, Boggess MM, Scott HM.To determine the effect of ocular blinkers on driving horses' reactions to visual and audible stimuli. Methods: Balanced crossover trial with horses randomly assigned to either wear blinkers or not wear blinkers first or second, then subjected to repeated sequences of four distinct stimuli (chain rattle, cap gun, umbrella opening, and shaking of an aluminum can containing coins). Two weeks later, this process was repeated with the ordering of wearing blinkers reversed. Methods: Eight driving horses of various breeds. Methods: Responses were recorded quantitatively as inter-beat times (the time...
Vörös K, Holmes JR, Gibbs C.This study was designed to evaluate the accuracy of two-dimensional echocardiography (2DE) in determining the left ventricular volume (LVV) of the horse in vitro. After examining the shape of the left ventricular silicon rubber casts of four equine hearts, two modified Simpson's rule methods (Model A and Model B) as combinations of conical shapes and one biplane area-length method as a single cone (Model C) were chosen for volume calculations. One long axis and three short axis planes were used for linear and area 2DE measurements, respectively. The ventricular length (L) was calculated from t...
Ramos GV, Titotto AC, da Costa GB, Ferraz GC, de Lacerda-Neto JC.The maximal lactate steady state (MLSS) is a well-known gold standard method for determining the aerobic capacity of athletic horses. Owing to its high cost and complex execution, there is a search for standardized exercise tests that can predict this value in a single session. One of the methods described for this purpose is the lactate minimum test (LMT), which could be more accurate despite being adequate to predict MLSS. This study aimed to examine the impact of training on the speed corresponding to lactate minimum speed (LMS) and to apply new mathematical methods to evaluate the fitness ...
Guyo M, Tareke M, Tonamo A, Bediye D, Defar G.This study was conducted to evaluate morphometric traits of horse ecotypes reared in four districts of the Bale highlands, southeastern Ethiopia. Twenty-seven morphometric traits were measured from 500 horses (294 males and 206 females) of both sexes. Data were analyzed using SAS 2012. This study revealed that certain traits, such as head length, loin length, bi-ischial width, and sternum height of horses were similar. However, significant differences ( < 0.0001, < 0.01, < 0.05) were observed in other traits across the districts. All traits were affected by age ( < 0.05) except rump width an...
Taddey CM, Roecken M, Kreling KM, Cruz AM.Reliable lameness thresholds for vertical head displacement for trotting on a circular path and on different surfaces have yet to be defined. Withers movement in lame horses could help improve the diagnostic accuracy of sensor technology. Objective: To define head movement lameness threshold ranges and describe the relationship between head and withers movement during trotting under different circumstances in sound and forelimb lame horses. Methods: Retrospective analysis of clinical data and comparison with control group. Methods: Fifty-five sound and thirty-four naturally lame horses were tr...
Corbally AF, Fahey AG.Sale prices at auction significantly impact the economic return of sport horse production. This study aimed to determine factors associated with auction sales prices of sport horses at four maturity stages: foals, juveniles, young horses, and older horses. A total of 42,799 sales records from 2003 to 2022 were obtained from two Irish equine auction companies. A univariate regression model was used, and significant variables underwent multivariate analysis. Within each maturity category, factors associated with above-mean-priced horses differed from those associated with below-mean-priced horse...
Faithfull R, Lewis K, Drury E, McBride S.Despite welfare concerns, conflict behaviours (indicative of momentary states of acute stress) are common in horses during dressage competitions. Identifying factors that affect conflict behaviours during competition therefore has the potential to improve equine welfare. The aim of this exploratory study was to assess the effect of bridle type (double versus snaffle) in relation to other potential affecting factors (e.g., average head angle, competition level and type, tack variation) on conflict behaviours during dressage competition. An ethogram was created to analyse the conflict behaviour ...
Nagy A, Dyson S.There are no detailed data on complications of sacroiliac (SI) joint region injections or on the variability of the methods and circumstances of injections among clinicians. Objective: To describe complications following diagnostic, therapeutic and combined SI joint region injections and the details of how these are routinely performed by a large number of clinicians. Methods: Cross-sectional questionnaire survey. Methods: Clinicians (members of American and European specialist colleges and veterinarians known to the authors), invited by email, who had performed ≥1 SI joint region injection,...
Dallarosa P, Monteiro ER, Borenstein APS, Valle SF.Packed cell volume (PCV) is important for assessing a patient's health status. Some blood gas analyzers measure hematocrit, and the agreement with PCV varies among different analyzers. Objective: We aimed to determine the agreement between PCV measured by microcentrifugation and hematocrit measured by the Cobas b121 blood gas analyzer in dogs, cats, and horses. Methods: Whole blood samples for PCV and blood gas analysis were collected in lithium-heparin syringes and analyzed within 10 min of collection. Agreement and association between the PCV and Cobas b121 generated hematocrit were assess...
Liley H, Zhang J, Firth E, Fernandez J, Besier T.Population variance in bone shape is an important consideration when applying the results of subject-specific computational models to a population. In this letter, we demonstrate the ability of partial least squares regression to provide an improved shape prediction of the equine third metacarpal epiphysis, using two easily obtained measurements.
Rawlings CA, Bisgard GE.Renal clearance and excretion of endogenous substances were studied in 13 small adult ponies (152 plus or minus 93 (standard deviation (SD)) kg). Normal data of serum and urinary concentrations, clearance, and excretion of creatinine, osmolality, free water, sodium, potassium, and chloride during a 12-hour period are presented. Significant linear regressions on body weight (BW) were obtained for creatinine clearance (Ccr (ml/hr) = 127.2 times BW (kg) - 1553), osmolar clearance (Cosm(ml/hr) = 1.81 times BW (kg) m0.3), and free water (CH2O(ml/hr) = - 1.43 BW (kg) - 25.0). Compared with renal exc...
Goetz TE, Manohar M.The effect of age on maximal heart rate induced by IV infusion of isoproterenol was studied in 19 healthy, sedentary, normothermic horses ranging in age from 0.25 to 9.90 years. Isoproterenol was administered IV (1.0 micrograms/kg of body weight/min) for 3 minutes, and the heart rate attained during the last 30 seconds of the infusion was determined. Linear regression of the maximal heart rate on age suggested that the rate decreased with age in a trend described by the equation: maximal heart rate (beats/min) = 209.63 - 3.28 x age (years). The regression coefficient (r) for this relation was ...
Thomas DE, Beadle RE.The pharmacokinetics of 3-methylindole (3MI) given orally in 2 doses (10 mg/kg and 20 mg/kg) to horses were determined. The pharmacokinetic plasma-concentration profiles for 3MI (10- and 20-mg/kg dosages) in horses were represented by a 2-compartment open model with first-order absorption, as determined by nonlinear least-squares regression analysis. Absorption of 3MI at both dosages was rapid. Comparisons of the peak plasma concentrations, the postdistribution half lives, total clearances, and areas under the curve of the plasma-concentration profiles between the 10- and the 20-mg/kg dosages ...
Asai Y, Matsui A, Osawa T, Kawai M, Kondo S.Ten Thoroughbred yearlings (5 females and 5 males) were used to examine the effect of time of grazing on pasture forage and digestible energy (DE) intake, bodyweight gain and DE expenditure in grazing activity. Five females were grazed for 17 h/day (LTG), 5 males were grazed for 7 h/day (STG) and they were fed differently. As a result, DE intake from pasture forage of LTG horses and STG horses was 27.3 and 12.7-13.9 Mcal/day, respectively. The average daily gain (ADG) of LTG and STG horses was 0.37 and 0.39-0.61 kg/day, respectively. The regression lines between DE intake and ADG of both group...
Huricha , Kawai M, Inose Y, Yamada F, Ninomiya S.In this study, we investigated maternal effects on the growth of Hokkaido native horses kept outdoors throughout the year. We used the data on body weight (BW), height at withers (HW), heart girth (HG), and cannon circumference (CC) of 517 foals during the first year of life to (1) examine the growth patterns by comparing six linear mixed models and (2) analyze the maternal effect on BW, HW, HG, and CC for each month by estimating variance components. The segmented polynomial third-order regression equation was selected as the best model for all the traits. The estimated proportion of variance...
Selecky ME, Louie EW, Donnelly C, Finno CJ, Morgan JM.Echocardiographic reference intervals for Quarter Horses are infrequently reported. Objective: To provide standard echocardiographic measurements for sedentary Quarter Horses and evaluate the relationship between physical characteristics (body weight, age, sex) and echocardiographic measurements. Methods: Forty-one sedentary Quarter Horses, free of cardiac disease, from a university research herd. Methods: A cross-sectional study evaluating standardized echocardiograms performed on sedentary Quarter Horses (41) between 2020 and 2022. Reference intervals were calculated for raw and weight-corre...
Thomas HL, Zaruby JF, Smith CL, Livesey MA.Castration of horses is considered a common and routine surgical procedure, but the potential for complications is high. By far the most serious of these is eventration. The objectives of this study were to determine the long-term survival of horses undergoing surgical treatment of indirect (1) inguinal eventration of the small intestine following castration, and to identify prognostic indicators for survival. The case records of 18 horses undergoing surgical treatment of postcastration eventration (PCE) between 1985 and 1995 were reviewed. Follow-up information was obtained by telephone inter...
