Logistic regression is a statistical method used for modeling the probability of a certain class or event, such as the presence or absence of a particular condition, based on one or more predictor variables. In equine research, logistic regression can be applied to analyze various factors affecting horse health and performance. This method allows researchers to evaluate the relationship between independent variables, such as age, breed, and physiological parameters, and a binary outcome, such as the occurrence of a disease or a performance level. Logistic regression is valuable for identifying potential risk factors and making predictions about health outcomes in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the application, methodology, and findings of logistic regression in equine studies.
Murray RC, Walters JM, Snart H, Dyson SJ, Parkin TD.The aim of this study was to describe the prevalence of illness and lameness at different anatomical sites in registered United Kingdom dressage horses and to identify risk factors for lameness. A questionnaire was sent to all 11,363 registered members of British Dressage in 2005, with one questionnaire assigned per horse. Four multivariable logistic regression models were developed for each section of the questionnaire. A final mixed effects logistic regression model was developed which combined the results from all prior models. Owners reported that 33% of horses had been lame at some time d...
Sugita S, Oki H, Hasegawa T, Ishida N.Estimation formulas for the morbidity of horses infected with equine influenza virus by linear regression, logistic regression and probit transformation were developed, using data from the outbreak at the Sha Tin Racing Track in Hong Kong in 1992. Using these formulas, we estimated the equine influenza virus morbidity rates at training centers belonging to the Japan Racing Association (JRA) in October 1997 and in October 1998. In 1998 JRA started a new vaccination program, and every horse must now be vaccinated twice per year. At that time, the vaccine included two US lineage virus strains, th...
Hill AE, Gardner IA, Carpenter TE, Stover SM.To assess concurrently the effects of moderate ligamentous suspensory apparatus injury (MLSAI), racing-speed exercise, and horseshoe characteristics on risk of catastrophic suspensory apparatus failure (SAF) or metacarpal condylar fracture (CDY) in forelimbs of racehorses. Methods: Cadavers of 301 Thoroughbred racehorses (108 with SAF, 33 with CDY and 160 control horses). Methods: A cross-sectional epidemiologic study was used to describe distributions and relationships between MLSAI, exercise, and horseshoe variables. Logistic regression was used to assess potential risk factors for developin...
Ohmura H, Hiraga A, Takahashi T, Kai M, Jones JH.To determine prevalence of atrial fibrillation (AF) immediately after racing among racehorses that finished well behind the winners and examine potential risk factors for AF in these horses. Methods: Case-control study. Methods: 39,302 racehorses representing 404,090 race starts in races sanctioned by the Japan Racing Association between 1988 and 1997. Methods: Horses that finished > or = 4 (turf races) or 5 (dirt races) seconds behind the winner or that did not complete the race were examined for AF within 5 minutes after the race. Logistic regression and chi2 analyses were used to determine ...
McCarthy HE, Proudman CJ, French NP.The geographical spread of grass sickness between 1909 and 1999, particularly in England and Wales, is described, and the experimental investigations to identify a causal agent are summarised. The epidemiological techniques used to investigate grass sickness vary from clinical observations, to more advanced methods such as case-control studies using logistic regression analyses. Several risk factors for grass sickness have been reported consistently (age, time of year and recent movement to new pasture or premises) and several others have been reported for which the findings remain inconsisten...
Martin GS.To evaluate effects of sex, fracture configuration, affected limb, and screw placement on outcome of Thoroughbreds with condylar fractures involving the third metacarpal or metatarsal bone. Methods: Cohort study. Animals-56 horses. Methods: Age, sex, affected limb, fracture configuration, fracture length, fracture fragment width, and distance of the most distal screw from the articular surface were analyzed in logistic regression models. Results: Females were more likely to have displaced fractures and race in fewer races after surgery than males. Sex and fracture configuration were associated...
Ross WA, Kaneene JB, Caron JP, Gallagher KF, Gardiner JC.The objective of this study was to identify factors that may affect recovery from and duration of a case of lameness in a stratified random sample of Michigan horses. This was done using data from Phase-II of the Michigan equine monitoring system (MEMS Phase-II), the equine health-monitoring study [Kaneene et al., Prev. Vet. Med. 29 (1997b) 277-292; Ross and Kaneene, Prev. Vet. Med. 28 (1996a) 209-224; Ross and Kaneene, Prev. Vet. Med. 29 (1996b) 59-75; Ross et al., Am. J. Vet. Res. 59 (1997) 23-29]. In this study, statistical modelling was conducted to evaluate risk factors affecting recovery...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Jack RA, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods L.To investigate relationships of several racehorse characteristics and race conditions with risk of a catastrophic musculoskeletal injury (CMI) resulting in euthanasia in Thoroughbreds during racing in California in 1992. Methods: Retrospective longitudinal study. Methods: Thoroughbreds that incurred CMI during racing and all California race entrants in 1992. Methods: Necropsy records were reviewed, and race start information was obtained. Incidence risk of CMI/1,000 race entrants was estimated. Relationships between CMI during racing and race-meet, entrant age and sex, race type and length, an...
Polzer J, Slater MR.A case-control study was conducted at the Texas Veterinary Medical Center between January 1, 1986 and December 31, 1991. Logistic regression was used to assess age, breed, sex, and seasonality as risk factors for equine laminitis. There were 70 acute cases, 183 chronic cases, and 779 controls. No statistical association was found between age, breed, sex, or seasonality and the diagnosis of acute laminitis. For chronic cases, the estimated odds ratio was statistically significant for age (OR = 1.05, 95% CI (1.02, 1.08)) and for the diagnosis of laminitis in the third quarter of the year (OR = 2...
Cohen ND, Matejka PL, Honnas CM, Hooper RN.The association between various management factors and development of colic was studied in 821 horses treated for colic and 821 control horses treated for noncolic emergencies by practicing veterinarians in Texas between Oct 1, 1991 and Dec 31, 1992. History of previous colic and history of previous abdominal surgery were found to be significantly associated with colic. Change in stabling conditions during the 2 weeks prior to the time of examination, recent change in diet, and recent change in level of activity significantly increased the risk for development of colic. Changes in activity lev...
Dolvik NI.Of 508 four-year-old coldblooded trotters examined for carpitis, 135 (27%) had the condition. Thirty horses had unilateral carpitis on the left frontlimb, 52 on the right frontlimb and 53 had bilateral carpitis. Of these horses, 105 were stallions, 135 were geldings and 269 were mares. The prevalence of carpitis in these three groups was 25%, 25% and 28%, respectively. Information was obtained on the training regimes in four periods of the life of 378 horses. The odds ratios for the training variables were of the same order in all four periods. In logistic regression analyses on the training v...
The proposed biological mechanisms for exercise-induced pulmonary haemorrhage (EIPH) are many and varied. Better knowledge of risk factors should lead to achievable measures to reduce the incidence. Objective: To identify risk factors associated with epistaxis following racing in UK Thoroughbreds, to gain possible insights into the pathogenesis of the condition and to investigate the association between epistaxis and race finishing position. Methods: The association of epistaxis occurring on UK racecourses between 1996 and 1998 with a wide range of race-, horse- and start-level variables was e...
Axt CW, Springer A, Strube C, Jung C, Naucke TJ, Müller E, Schäfer I.Equine piroplasmosis (EP) is caused by (.) and/or (.) . The aim was to assess the percentage of positive test results for EP in horses in Europe and to identify risk factors for pathogen contact/infection. This study included results from PCR and competitive enzyme-linked immunosorbent assay testing requested by European veterinarians between 2008 and 2021. Binary bivariate logistic regression was used to analyze risk factors. A total of 4060 horses were included. PCR testing was positive in 9.7% (154/1589), serology for in 15.2% (393/2591) and for in 6.8% (175/2578). The odds of positive...
Hepworth-Warren KL, Erwin-Craig SJ, Love K.To determine whether student involvement in intravenous catheter (IVC) placement increases the risk for complications and to report the rate and types of complications associated with IVCs in adult horses in a university teaching hospital. Methods: 455 IVCs placed in 394 horses. Methods: Data relevant to IVC placement and removal were retrieved from an electronic medical record search including records of adult horses from January 1 to December 31, 2022. Data retrieved from records included the role of the individual who prepared the site and placed the IVC, site of IVC placement, and type of ...
Schrurs C, Dubois G, Van Erck-Westergren E, Gardner DS.In-training racehorse physiological data can be leveraged to further explore race-day performance prediction. To date, no large retrospective, observational study has analysed whether in-training speed and heart rate recovery can predict racehorse success. Speed (categorised as 'slow' to 'fast' according to the time taken to cover the last 600 m from a virtual finish line) and heart rate recovery (from gallop to 1 min after exercise) of flat racehorses (n = 485) of varying age, sex and type according to distance (e.g., sprinter, miler and stayer) were obtained using a fitness tracker from a si...
Tamura N, Yoshihara E, Seki K, Mae N, Kodaira K, Iimori M, Yamazaki Y, Mita H, Urayama S, Kuroda T, Ohta M, Kasashima Y.The potential value of hypervascularity detected with power Doppler ultrasonography (PDU) within equine superficial digital flexor tendon (SDFT) as a prognostic factor of SDFT injury is not clear. The purpose of this study was to test the hypothesis that hypervascularity within SDFT is one of the risk factors for subsequent severe SDFT injury and to evaluate the prognostic value. A prospective cohort study of 97 Thoroughbred racehorses without any clinical signs of SDFT injury was conducted. Six variables of age, body weight, sex, the cross-sectional area of SDFT, PDU signal within SDFT and ex...
Flores JG, Bueno VC, Bastos HBA, Rechsteiner SMDEF.Reproductive biotechniques in the equine species have advanced in the last decade and horse breeders have started to question the possibilities of interfering in the determination of foal sex. The aim of the present study was to verify whether the variables mares and stallion's age, side of the ovary containing the preovulatory follicle, preovulatory follicle diameter, time between breeding and ovulation, and ovulation inducing hormones influence the sex of the foal. A total of 259 reproductive cycles of 160 mares and 22 Thoroughbred stallions were used. Statistical analysis was performed usin...
Norton AM, Rosanowski SM, O'Brien T.Epiglottic entrapment (EE) is a common cause of poor performance in racing standardbreds (STBs) and thoroughbreds (TBs). There is limited information published on the condition in STB racehorses and limited information on factors associated with return to racing available for either breed. Unassigned: This study investigated and compared the pre surgical findings, post-surgical complications and racing performance in STBs and TBs undergoing surgery for correction of EE. Associations between signalment and pre-surgical findings, and the presence of complications and racing post-surgery were com...
May A, Riley CB, Scharre A, Zablotski Y, Padalino B.Equine road transport is stressful and associated with an increased risk of behavioral problems, injuries, respiratory and gastrointestinal diseases. This cross-sectional survey-based study aimed to describe transport-related practices and the perception of behavioral and health issues in Germany. The survey targeted horse owners (amateurs and professionals) and obtained demographic details, the participant's experience, frequency and duration of transportation, and behavioral and health problems related to equine transportation. Associations among behavioral and health problems and transport ...
Bennet ED, Parkin TDH.The Equine Injury Database (EID) is a census-level record of Thoroughbred racing in North America, currently recording 95.6% of all race starts in 2023, along with partial training and veterinary histories of each horse. Objective: To identify horse-, race- and track-level risk factors associated with race-related fatal musculoskeletal injury (MSI) of Thoroughbred racehorses in North America. Methods: Retrospective cohort study. Methods: The study cohort included all race starts made by horses born after 31 December 2006, at tracks that fully report to the EID and consisted of 3,851,659 race s...
Román Durá B, Dunham O, Grulke S, Salciccia A, Dupont J, Sandersen C.Equine anesthesia is related to high morbidity and mortality rates and recent studies suggested that the period of recovery remains the phase associated with the greatest risk of mortality in horses. Intraoperative hypotension, hypoxemia, and hypercapnia are recognized as potential determinants of recovery quality. This study, conducted at the Equine University Hospital of Liege, aimed to explore how these factors influence recovery outcomes and compare complications between non-emergency and emergency procedures. We analyzed data from 1057 horses, with a mean weight of 498 kg (ranging from 15...
Murase H, Wachi S, Matsuyama R, Makita K, Sato F.Pituitary pars intermedia dysfunction (PPID) is an age-related disease considered to have a negative impact on fertility. To understand the true impact of PPID on fertility, the influence of age must be considered. Objective: This study aimed to assess the impact of PPID on fertility while accounting for the effect of aging. Methods: A total of 332 Thoroughbred mares aged 10-20 years and managed across 137 private farms in Hidaka, Hokkaido, Japan were classified as PPID, equivocal, or non-PPID based on plasma adrenocorticotropic hormone concentration in 2019 and 2020. The prevalence of PPID an...
Gozalo-Marcilla M, Redondo JI, Bettschart-Wolfensberger R, Domenech L, Doménech J, Johnston GM, Taylor PM.To report on the Confidential Enquiry into Perioperative Equine Fatalities 4 (CEPEF4). Methods: Confidential, observational, prospective, multicentre, cohort study. Methods: 47,396 horses/ponies undergoing general anaesthesia (GA). Methods: Characteristics of each GA (249 variables) were collected. Outcomes after seven days were ALIVE (or discharged), EUTHANASIA or DEAD. Logistic regression analysed patient demographics and the anaesthetic drugs (p < 0.05). Results: Data were collected from 47,396 GAs in 93 centres in 28 countries. Death rates were 1.2% overall, 0.6% for cases classified as NO...
Sanchez-Arjona R, Lopez Cruz C, Hague BA, Jayawickrama J, Kamm JL.To evaluate the outcomes of diode laser-facilitated (DLF) ankylosis using different surgical techniques to treat distal tarsal osteoarthritis (OA) in horses. Methods: Retrospective cohort study. Methods: A total of 64 client-owned horses with distal tarsal OA treated with DLF ankylosis between 2011 and 2021 in a referral hospital were included. Methods: DLF ankylosis techniques included: intra-articular diode laser (L), diode laser with periarticular drilling (L + D) and diode laser with cuboidal bone fenestration (L + F). Horses requiring a second surgery formed a fourth group (T). Ou...
Choi Y, Rosanowski SM, Parkin TD.To identify risk factors associated with complete humerus fractures in Thoroughbreds in South Korea. Unassigned: A retrospective case-control design with multivariable logistic regression was used. This study included 131 Thoroughbreds diagnosed with complete humerus fractures following racetrack activity between 2009 and 2022 (inclusive). Additionally, 660 healthy Thoroughbreds (699 observations) with at least 1 racetrack activity during the same period were included as controls. Unassigned: A total of 8 variables were associated with the risk of complete humerus fractures. Notably, horses wi...
