Topic:Case-Control Study
A case-control study is a type of observational research design used to identify and evaluate factors that may contribute to a particular outcome by comparing subjects with a specific condition (cases) to those without the condition (controls). In equine research, case-control studies are employed to investigate various health-related issues affecting horses, such as disease outbreaks, lameness, or behavioral disorders. These studies help identify potential risk factors or associations by analyzing the differences in exposure or characteristics between the two groups. This page compiles peer-reviewed research studies and scholarly articles that explore the methodology, application, and findings of case-control studies in equine science, providing insights into their role in advancing equine health and management practices.
Caudal lumbar vertebral fractures in California Quarter Horse and Thoroughbred racehorses. To gain insight into the pathophysiology of equine lumbar vertebral fractures in racehorses. Objective: To characterise equine lumbar vertebral fractures in California racehorses. Methods: Retrospective case series and prospective case-control study. Methods: Racehorse post mortem reports and jockey injury reports were retrospectively reviewed. Vertebral specimens from 6 racehorses affected with lumbar vertebral fractures and 4 control racehorses subjected to euthanasia for nonspinal fracture were assessed using visual, radiographic, computed tomography and histological examinations. Results: ...
Airborne particulates (PM10) and tracheal mucus: A case-control study at an American Thoroughbred racetrack. Particle mapping within stalls has demonstrated a relationship between particulate concentrations and visible accumulations of tracheal mucus. However, measurement of breathing zone particulate concentrations, which is the most accurate way to measure exposure, has not been performed to determine the relationship between exposures and accumulations of tracheal mucus sufficient to affect performance. Objective: To compare breathing zone particulate exposures between horses with tracheal mucus scores (MS) previously demonstrated to affect performance (MS≥2) and those without (MS = 0) visible t...
The effect of exercise on plasma concentrations of inflammatory markers in normal and previously laminitic ponies. The mechanisms underlying predisposition to pasture-associated laminitis remain unclear; chronic inflammation is implicated, and this may be exacerbated by physical inactivity. Objective: To determine whether exercise affects the inflammatory profile of normal and previously laminitic ponies. Methods: Prospective case-control study. Methods: The short (1 day) and longer term (14 days) effects of low intensity (10 min walking and 5 min trotting) exercise on plasma inflammatory marker concentrations in normal (NL) and previously laminitic (PL) nonobese ponies (n = 6/group) was determined. Plasma...
Plasma fructosamine concentrations in horses with pituitary pars intermedia dysfunction with and without laminitis. Plasma fructosamine concentration ([fructosamine]) is believed to reflect medium term, average blood glucose concentration and in a previous study was higher in horses with active laminitis than in normal horses. Pituitary pars intermedia dysfunction (PPID) is associated with hyperglycaemia and laminitis. Objective: To test the hypotheses that: [fructosamine] is higher in PPID cases than normal animals; furthermore, that within cases of PPID [fructosamine] is higher in those with active laminitis than nonlaminitic cases and in cases that have been affected by active laminitis in the preceding ...
Risk of septic arthritis after intra-articular medication: a study of 16,624 injections in Thoroughbred racehorses. The aims of this study were to determine the risk of septic arthritis after intra-articular medication (IAM) and to identify potential risk factors for this complication. Methods: A retrospective and prospective descriptive study of prevalence, and matched case-control study for risk factors. Results: Of 16,624 joints injected in 1103 horses at 6695 horse-visits, septic arthritis occurred as a complication in 13 joints (13 horses). The risk of septic arthritis following IAM was 7.8 cases per 10,000 injections or 1 case per 1279 injections. Veterinarian and type of corticosteroid were identifie...
Comparison of the use of scapular ultrasonography, physical examination, and measurement of serum biomarkers of bone turnover versus scintigraphy for detection of bone fragility syndrome in horses. To define scintigraphic, physical examination, and scapular ultrasonographic findings consistent with bone fragility syndrome (BFS) in horses; develop indices of BFS severity; and assess accuracy of physical examination, scapular ultrasonography, and serum biomarkers for BFS diagnosis. Methods: Prospective case-control study. Methods: 48 horses (20 horses with BFS and 28 control horses). Methods: Horses underwent forelimb scintigraphic evaluation, physical examination, scapular ultrasonography, and serum collection. Scintigraphy was used as a reference standard to which physical examination, s...
Traditional and quantitative assessment of acid-base and shock variables in horses with atypical myopathy. Descriptions of acid-base disturbances in atypical myopathy (AM) are limited. Objective: Describe and compare traditional and quantitative acid-base abnormalities and cardiovascular shock status in horses with AM at admission. Methods: 34 horses with AM, 15 healthy controls. Methods: Retrospective case-control study. Records were searched for shock variables (packed cell volume [PCV], blood urea nitrogen [BUN], heart and respiratory rate) and acid-base variables (venous blood gas analysis, electrolytes, total protein, lactate) on admission. Base excess (BE) of free water (BEfw), chloride (BEcl...
Effectiveness of safety vests in pediatric horseback riding. Despite the benefit of safety vests to the reduction of torso injuries in children and adolescents is unclear, its' use is recommended. The aim of the present study is to determine the effectiveness of safety vests actually used in pediatric equestrian activities. Methods: In this case-control-study, we analyzed the accidents of 92 riders aged 18 or younger who fell off a horse onto his/her torso during a period of 18 months. Data were gathered from the clinical records. Additionally, a questionnaire was administered on the day of trauma by the patients and/or their parents. Results: The cases...
Absence of evidence for bornavirus infection in schizophrenia, bipolar disorder and major depressive disorder. In 1983, reports of antibodies in subjects with major depressive disorder (MDD) to an as-yet uncharacterized infectious agent associated with meningoencephalitis in horses and sheep led to molecular cloning of the genome of a novel, negative-stranded neurotropic virus, Borna disease virus (BDV). This advance has enabled the development of new diagnostic assays, including in situ hybridization, PCR and serology based on recombinant proteins. Since these assays were first implemented in 1990, more than 80 studies have reported an association between BDV and a wide range of human illnesses that i...
Eca20 microsatellite polymorphisms in equine viral arteritis-infected horses from Argentina. We investigated the association of equine arteritis virus (EAV) infection and three short tandem repeat (STR) polymorphisms located within or in close proximity to equine lymphocyte antigen (ELA) region. We used a case-control design as a first approach before proceeding to select candidate genes. One hundred and sixty-five Silla Argentino horses were taken in 2002 from positive serological detections of EAV in Argentina, to determine whether STR genotypes were correlated to genetic susceptibility to EVA. Allele frequency distribution did not show significant differences between both groups (P...
Retrospective evaluation of crib-biting and windsucking behaviours and owner-perceived behavioural traits as risk factors for colic in horses. Although crib-biting (cribbing)/windsucking has previously been associated with 2 types of colic, additional research into the possible role of other behaviours on incidence of colic by type and severity has not been undertaken. Objective: To investigate: a relationship between cribbing/windsucking and colic; a relationship between cribbing/windsucking and different types of colic, both medical and surgical; and whether horses displaying specific behaviour traits were more likely to have had colic. Methods: A matched case-control retrospective study was conducted evaluating horses with various...
Comparison of survival rates for geriatric horses versus nongeriatric horses following exploratory celiotomy for colic. To determine how survival rates in geriatric horses (>or= 20 years old) undergoing abdominal exploratory surgery for colic compare with survival rates for younger (nongeriatric) horses. Methods: Retrospective case-control study. Methods: 56 geriatric horses and 487 nongeriatric horses undergoing exploratory celiotomy for colic. Methods: Medical records of all horses undergoing emergency abdominal exploratory surgery for primary gastrointestinal tract lesions over a 10-year period were reviewed. Data retrieved included signalment, primary gastrointestinal tract lesion, whether the horse was ...
Exercise distance and speed affect the risk of fracture in racehorses. In order to gain insight into those training regimens that can minimise the risk of fracture in athletic populations, we conducted a large epidemiological study in racehorses. Thoroughbred racehorses provide a suitable model for studying fracture development and exercise-related risk factors in physically active populations. They represent a homogeneous population, undertaking intensive exercise programmes that are sufficiently heterogeneous to determine those factors that influence injury risk. Daily exercise information was recorded for a cohort of 1178 thoroughbreds that were monitored for ...
Esterified estrogens and conjugated equine estrogens and the risk of venous thrombosis. Clinical trial evidence indicates that estrogen therapy with or without progestins increases venous thrombotic risk. The findings from these trials, which used oral conjugated equine estrogens, may not be generalizable to other estrogen compounds. Objective: To compare risk of venous thrombosis among esterified estrogen users, conjugated equine estrogen users, and nonusers. Methods: This population-based, case-control study was conducted at a large health maintenance organization in Washington State. Cases were perimenopausal and postmenopausal women aged 30 to 89 years who sustained a first v...
Memory decay and performance-related information bias in the reporting of scores by event riders. We used data from a case-control study investigating risk factors for horse falls in the cross-country phase of eventing in Great Britain (GB) to examine evidence for memory decay and information bias. Responses to two questions obtained by telephone for 173 cases and 521 controls were examined for evidence of differential reporting according to the respondent's case-control status and performance in the dressage and cross-country phases of competitions. Information bias was found in the accuracy of reporting dressage penalty scores when analysed as a function of performance level (good/poor)....
Risk factors for atrial fibrillation during racing in slow-finishing horses. 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 ...
Case-control study to investigate risk factors for horse falls in hurdle racing in England and Wales. Between March 1, 2000 and August 31, 2001, a case-control study was conducted on 12 racecourses in England and Wales to identify and quantify the risk factors associated with horse falls in hurdle races. The cases and controls were defined so that variables relating to the horse, the jockey, the race and racecourse, and the jump could be considered. The cases were defined as a jumping effort at a hurdle flight that resulted in a fall, and the controls were defined as a successful jump over a hurdle at any of the 12 racecourses within 14 days before or after the case fall. Conditional logistic ...
Seroprevalence of antibodies against Neospora caninum in diagnostic equine serum samples and their possible association with fetal loss. A case-control study of the association between the presence of serum antibodies against Neospora spp. and fetal loss was performed on serum samples submitted to a veterinary diagnostic laboratory in northwestern United States. Control sera were randomly selected from those submitted from healthy horses for routine equine infectious anemia testing required for regulatory health certification. Case sera were randomly selected from those submitted from aborting mares for diagnostic workup. Based on a 1:50 or greater titer on the indirect fluorescent antibody test, 8% of the 160 control sera and ...
Intradermal testing in healthy horses and horses with chronic obstructive pulmonary disease, recurrent urticaria, or allergic dermatitis. To compare responses to a variety of intradermally injected allergens among healthy horses and horses with chronic obstructive pulmonary disease (COPD), recurrent urticaria (RU), and atopic dermatitis-insect hypersensitivity (allergic dermatitis [AD]). Methods: Case-control study. Methods: 86 horses. Methods: Results of intradermal testing for horses with COPD, RU, or AD were compared with results for healthy horses. Results: Compared with healthy horses, horses with COPD, RU, and AD were significantly more likely to have positive (> or = 3+) reactions to intradermal allergens (molds, weeds, t...
Association of disease with isolation and virulence of Rhodococcus equi from farm soil and foals with pneumonia. To determine whether isolation and virulence of Rhodococcus equi from soil and infected foals are associated with clinical disease. Methods: Cross-sectional and case-control study. Methods: R equi isolates from 50 foals with pneumonia and soil samples from 33 farms with and 33 farms without a history of R equi infection (affected and control, respectively). Methods: R equi was selectively isolated from soil samples. Soil and clinical isolates were evaluated for virulence-associated protein antigen plasmids (VapA-P) and resistance to the beta-lactam antibiotics penicillin G and cephalothin. Mic...
Intrinsic, management, and nutritional factors associated with equine motor neuron disease. 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...
Results of a combined dexamethasone suppression/thyrotropin-releasing hormone stimulation test in healthy horses and horses suspected to have a pars intermedia pituitary adenoma. To evaluate results of a combined dexamethasone suppression/thyrotropin-releasing hormone (TRH) stimulation test in horses suspected clinically to have a pars intermedia pituitary adenoma (PIPA). Methods: Case-control study. Methods: 7 healthy adult horses and 5 horses suspected to have a PIPA. Methods: A baseline blood sample was collected, and dexamethasone (40 micrograms/kg [18 micrograms/lb] of body weight, IV) was administered; a second blood sample was collected 3 hours later, and TRH (1.1 mg, IV) was administered; serial blood samples were collected 15, 30, 45, 60, and 90 minutes and 21...
Case-control study of the association between various management factors and development of colic in horses. Texas Equine Colic Study Group. 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...
Sports activities and risk of testicular cancer. The relationship of testicular seminoma with several factors was explored using a case-control study. Previously recognized associations with cryptorchidism and infantile inguinal hernia were confirmed and relationships were also found with cycling and horse-riding. These findings represent the first relationships of testicular cancer with well-defined postnatal risk factors.
Risk factors for methicillin-resistant Staphylococcus aureus colonization in horses admitted to a veterinary teaching hospital. Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging problem in horses; however, the epidemiology of infection and colonization is poorly understood. This study evaluated factors associated with MRSA colonization at the time of admission to a veterinary teaching hospital. A case-control study evaluating historical factors was performed. Previous colonization of the horse, previous identification of colonized horses on the farm, antimicrobial administration within 30 days, admission to the neonatal intensive care unit, and admission to a service other than the surgical service were...