Topic:Longitudinal Study
A longitudinal study in the context of equine research involves the systematic observation and data collection from the same group of horses over an extended period. This research approach aims to track changes and developments in various health parameters, behaviors, or conditions within the equine population being studied. By repeatedly assessing the same subjects, researchers can identify patterns, establish temporal sequences, and infer potential causal relationships. Longitudinal studies in horses can encompass a wide range of topics, including growth and development, disease progression, and the impact of environmental or management changes. This page gathers peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of longitudinal studies in equine science.
Implantation of bone marrow-derived mesenchymal stem cells demonstrates improved outcome in horses with overstrain injury of the superficial digital flexor tendon. Mesenchymal stem (progenitor; stromal) cell (MSC) therapy has gained popularity for the treatment of equine tendon injuries but without reports of long-term follow-up. Objective: To evaluate the safety and reinjury rate of racehorses after intralesional MSC injection in a large study of naturally occurring superficial digital flexor tendinopathy and to compare these data with those published for other treatments. Methods: Safety was assessed clinically, ultrasonographically, scintigraphically and histologically in a cohort of treated cases: 141 client-owned treated racehorses followed-up for a...
Optimum conditions for serum clearance of iodixanol, applicable to the estimation of glomerular filtration rate in horses. To estimate the glomerular filtration rate (GFR) in horses, an optimum dose of the nonionic contrast medium iodixanol as a tracer was assessed with blood-sample times. Iodixanol was administered intravenously at 10-40 mg I/kg to geldings and mares, and blood was collected 30, 60, 90, 120, 150, and 180 min later. Serum iodixanol concentration was determined by high-performance liquid chromatography (HPLC), and serum urea nitrogen (UN) and creatinine concentrations were also measured. The combination of 20 mg I/kg iodixanol and sampling times of 60, 90, and 120 min after injection was considered...
Descriptive results from a longitudinal study of airway inflammation in British National Hunt racehorses. Rates of airway inflammation in young racehorses decrease with time but it is not clear whether this is associated with increasing age or time exposed to the training environment. The structure of the British National Hunt (NH) population allowed closer examination of this relationship. Objective: To compare rates of inflammatory airway disease diagnosed by tracheal sampling (trIAD), and its components, in NH racehorses by age and training history and with published rates in young racehorses. Methods: A prospective, longitudinal study was conducted on 5 NH yards over 2 years. Period sample pre...
Quantification of left ventricular longitudinal strain, strain rate, velocity, and displacement in healthy horses by 2-dimensional speckle tracking. The quantification of equine left ventricular (LV) function is generally limited to short-axis M-mode measurements. However, LV deformation is 3-dimensional (3D) and consists of longitudinal shortening, circumferential shortening, and radial thickening. In human medicine, longitudinal motion is the best marker of subtle myocardial dysfunction. Objective: To evaluate the feasibility and reliability of 2-dimensional speckle tracking (2DST) for quantifying equine LV longitudinal function. Methods: Ten healthy untrained trotter horses; 9.6 ± 4.4 years; 509 ± 58 kg. Methods: Prospective study. Re...
Retrospective study of scintigraphic and radiological findings in 21 cases of enostosis-like lesions in horses. Records of horses admitted to a veterinary surgery in the UK for lameness investigation during 2000 to 2008 were reviewed. Twenty-one horses were identified with both scintigraphic and radiological evidence of enostosis-like lesions (ELLs), in which 68 individual foci of increased radiopharmaceutical uptake were confirmed in 57 long bones. The presenting lameness was attributed to ELLs in 15 of 21 (71 per cent) horses; the remainder were thought to be incidental findings. Five horses were subjected to a repeat examination, four of which showed the occurrence of new lesions in the same or diffe...
Longitudinal study of antimicrobial-resistant commensal Escherichia coli in the faeces of horses in an equine hospital. The increasing prevalence of antimicrobial resistance in bacteria represents a considerable problem for human and veterinary medicine, causing complications in the treatment of infections. Resistance in Escherichia coli from horses has been documented in commensal and pathogenic strains, but little information exists regarding the prevalence of such bacteria in hospitalised horses or associated risk factors. A longitudinal cohort study was conducted of 103 horses admitted to a referral equine hospital for more than 48 h, with faecal samples collected on hospital admission and subsequently ever...
Does work affect personality? A study in horses. It has been repeatedly hypothesized that job characteristics are related to changes in personality in humans, but often personality models still omit effects of life experience. Demonstrating reciprocal relationships between personality and work remains a challenge though, as in humans, many other influential factors may interfere. This study investigates this relationship by comparing the emotional reactivity of horses that differed only by their type of work. Horses are remarkable animal models to investigate this question as they share with humans working activities and their potential diff...
Clinical assessment and outcome of a single-layer technique for anastomosis of the small intestine in horses. In order to assess postoperative outcome in horses undergoing end-to-end anastomosis of the small intestine, performed using a one-layer technique, 15 horses that underwent exploratory coeliotomy, resection of the small intestine and end-to-end anastomosis using a continuous Lembert pattern were studied. Information on the age, breed, sex, diagnosis, treatment, complications and outcome of each case were obtained from medical records. Follow-up information was obtained via telephone conversations with clients and trainers. Five of the horses had short-term postoperative complications: one had ...
Longitudinal study of the renin angiotensin aldosterone system in purebred Spanish broodmares during pregnancy. During pregnancy, the coordinated interaction of the components of the renin-angiotensin-aldosterone system (RAAS) plays a vital role in accommodating the cardiovascular, haemodynamic and haematological needs imposed by foetal development and the placenta. This significantly influences the birth weight of the neonate and foetal viability. Although the evolution of each of the components of this system has been widely described in various species, it has not yet been clarified in the mare. Thus, the objectives of the present research were: 1) to establish reference values for renin (REN), angio...
Mild exercise early in life produces changes in bone size and strength but not density in proximal phalangeal, third metacarpal and third carpal bones of foals. Exercise or lack of it in early life affects chondro-osseous development. Two groups of horses were used to investigate the effects of age and exercise regimen on bone parameters of diaphyseal, metaphyseal, epiphyseal and cuboidal bones of the distal limb of Thoroughbreds. One group had exercised only spontaneously from an early age at pasture (PASTEX group), while the other group of horses were exposed to a 30% greater workload through additional defined exercise (CONDEX). Longitudinal data from peripheral quantitative computed tomography (pQCT) were obtained from eight scan sites of the left...
Effects of long-time series of data on genetic evaluations for performance of Swedish Warmblood riding horses. For Swedish Warmblood sport horses, breeding values (BVs) are predicted using a multiple-trait animal model with results from competitions and young horse performance tests. Data go back to the beginning of the 1970s, and earlier studies have indicated that some of the recorded traits have changed through the years. The objective of this study was to investigate the effects of including all performance data or excluding the older ones compared to a bivariate model (BM) considering performance traits in early and late periods as separate traits. The bivariate approach was assumed to give the mo...
Amino acid profile during exercise and training in Standardbreds. The objective of this study is to assess the influence of acute exercise, training and intensified training on the plasma amino acid profile. In a 32-week longitudinal study using 10 Standardbred horses, training was divided into four phases, including a phase of intensified training for five horses. At the end of each phase, a standardized exercise test, SET, was performed. Plasma amino acid concentrations before and after each SET were measured. Training significantly reduced mean plasma aspartic acid concentration, whereas exercise significantly increased the plasma concentrations of alanin...
Serum biomarker levels for musculoskeletal disease in two- and three-year-old racing Thoroughbred horses: A prospective study of 130 horses. Biomarkers have shown some in vivo promise for the detection of musculoskeletal injuries, but further study to assess biomarker levels in clinical orthopaedic disease is required. Objective: To assess 7 serum biomarkers for the detection of musculoskeletal injuries. Methods: Two- and 3-year-old racehorses were entered into the study (n = 238). Exit criteria were lack of training for >30 days, or completion of 10 study months. Data from horses with solitary musculoskeletal injuries and completion of >2 months were analysed. Musculoskeletal injury was considered intra-articular fragmentation (IA...
Longitudinal study of an outbreak of Trypanosoma evansi infection in equids and dromedary camels in Israel. An outbreak of trypanosomoasis caused by Trypanosoma evansi involving horses, camels and donkeys occurred in a farm in Israel. A longitudinal study of two outbreak phases was conducted which included clinical monitoring, blood smears, packed cell volume (PCV), serology and polymerase chain reaction (PCR) followed by reverse dot blot (RDB) for the molecular detection of infection. This was the first reported T. evansi outbreak in domestic animals in Israel. Most of the camels on the farm (8/10; 80%) were diagnosed with T. evansi infection whereas infection was less prevalent in the horses (3/7;...
Longitudinal study of Australian stringhalt cases in France. Seventy horses with clinical evidence of Australian stringhalt were studied in France from 2003 to 2008. All horses but one had history of bilateral stringhalt and grazed pastures infested with Hypochoeris radicata (L.). They displayed hind limbs hyperflexion and an abnormal gait because of a distal axonopathy with a skeletal muscle denervation and atrophy. Fifty percentage of them recovered spontaneously in 8 months, and only the more affected horses were unable to recover even if they looked healthy on dry and hot days. Clinical troubles revealed also depression or aggressive behaviour, sugg...
Association of season and pasture grazing with blood hormone and metabolite concentrations in horses with presumed pituitary pars intermedia dysfunction. Pituitary pars intermedia dysfunction (PPID) is a risk factor for pasture-associated laminitis, which follows a seasonal pattern. Objective: Hormonal responses to season differ between PPID and unaffected horses. Methods: Seventeen horses aged 8-30 years (14 horses ≥ 20 years of age). Methods: Longitudinal observational study. Blood was collected monthly from August 2007 until July 2008 after pasture grazing and again after overnight stall confinement. Blood hormone and metabolite concentrations were measured and pasture grass samples were analyzed to determine carbohydrate content. Analysis...
A two-component nonlinear mixed effects model for longitudinal data, with application to gastric emptying studies. Gastric emptying studies are of great interest in human and veterinary medical research to evaluate effects of medications or diets for promoting gastrointestinal motility and to examine unintended side-effects of new or existing medications, diets, or procedures. Summarizing gastric emptying data is important to allow easier comparison between treatments or groups of subjects and comparisons of results among studies. The standard method for assessing gastric emptying is by using scintigraphy and summarizing the nonlinear emptying of the radioisotope. A popular model for fitting gastric emptyi...
Lateralised motor behaviour leads to increased unevenness in front feet and asymmetry in athletic performance in young mature Warmblood horses. Foot stance in grazing significantly influences hoof conformation and development from foal to yearling age. Objective: To conduct a longitudinal study to establish if the relationship between motor laterality and uneven front feet persisted in 3-year-old horses at the time of studbook selection and to investigate if such laterality and unevenness might influence the horses' ability to perform symmetrically while trotting, cantering and free jumping. Methods: Seventeen clinically sound but untrained (with only minimal experience of handling) and sound Warmblood horses that had participated in ...
Outcome and long-term follow-up of 20 horses undergoing surgery for caecal impaction: a retrospective study (2000-2008). If untreated, caecal impaction may progress to rupture of the caecum and reports of long-term outcome for horses undergoing surgery for caecal impaction are required. Objective: To describe short- and long-term complication rates for horses undergoing surgery for caecal impaction in an otherwise life-threatening gastrointestinal condition. Methods: Case records were reviewed for horses undergoing surgery for caecal impaction. Horses were included in the study if an abnormally large, fluid-distended or feed-impacted caecum was the primary diagnosis at surgery and excluded if the caecum had alre...
[Study of the correlation between the plasma viral load and protective immunity induced by the equine infectious anemia attenuated vaccine and its parental virulent strain]. The threshold hypothesis of attenuated lentiviral vaccine considers that the type of host response to infections of lentiviruses depends on the viral load. To evaluate the correlation between viral loads of the attenuated vaccine strain of equine infectious anemia virus (EIAV) and their effects to induce protective immunity, longitudinal plasma viral loads in groups of horses inoculated with either an attenuated EIAV vaccine strain (EIAV(DLV125)) or sub-lethal dose of an EIAV virulent strain (EIAV(LN40)) were compared. Similar levels of plasma viral loads ranging from 10(3)-10(5) copies/mL wer...
Stabling causes a significant increase in the pH of the equine airway. Regulation of pH homeostasis in the equine lung is poorly understood. Measurement of exhaled breath condensate (EBC) pH provided a simple, highly repeatable and noninvasive method for the longitudinal investigation of changes in airway pH in response to environmental changes. Stabling of horses was found to lead to a small (approximately 100-200 parts/billion) but significant (P < 0.001) increase in ambient ammonia concentration when compared to pasture. This increase in exposure to ambient ammonia concentration was associated with significant (P = 0.002) increases in EBC pH and exhaled amm...
Evaluation of a motorized morcellator for laparoscopic removal of granulosa-theca cell tumors in standing mares. To describe a motorized morcellator technique for laparoscopic removal of granulosa-theca cell tumors (GCT) in standing mares and to evaluate long-term outcome. Methods: Case series. Methods: Mares (n=7) aged 4-15 years, with unilateral GCT. Methods: Tumor size was determined by transrectal palpation and ultrasonography. Standing sedated mares had 3 laparoscopic portal sites in the paralumbar fossa. After laparoscopic observation of the GCT, the mesovarium was desensitized, the ovarian pedicle transected with a LigaSure device, and the ovary grasped with forceps and cut in cylindrical tissue b...
Long-term outcome after arthroscopic debridement of distal phalanx extensor process fragmentation in 13 horses. To report long-term outcome after arthroscopic removal of fragmentation of the extensor process of the distal phalanx in horses. Methods: Case series. Methods: Adult horses (n=13). Methods: Medical records (2003-2004) of horses that had arthroscopic debridement of fragmentation of the extensor process of the distal phalanx were reviewed. Inclusion criteria included: lameness localized to the foot, fragmentation of the extensor process of the distal phalanx debrided arthroscopically, and a follow-up period of > or = 4 years. Results: Of the 13 horses, lameness was resolved in 11 (85%) initia...
Temporal changes in concentrations of branched-chain amino acids in plasma on healthy mares and foals from birth to 24 weeks of age. The concentrations of branched-chain amino acids (BCAA; valine, leucine, isoleucine) were determined in plasma of 7 healthy thoroughbred mares and their foals from birth (0 week) to 24 weeks of age, using automated high-performance liquid chromatography. In foals, the concentrations of plasma valine were significantly high (p<0.05) at 16, 20 and 24 weeks. The concentrations of plasma leucine were significantly high (p<0.05) at 1 and 3 weeks. The concentrations of plasma isoleucine were significantly high (p<0.05) from 1 to 24 weeks. In mares, the concentrations of plasma valine were s...
A retrospective longitudinal study of animal and human rabies in Botswana 1989-2006. A longitudinal study of animal and human rabies covering 18 years from 1989 to 2006 was retrospectively conducted in order to highlight the epidemiological features and trends of the disease in Botswana. Over the 18-year period, a total of 4 306 brain specimens collected from various species of animals including human beings with clinical signs consistent with rabies were submitted to the National Veterinary Laboratory in Gaborone for confirmatory diagnosis. Of the samples submitted, 2419 cases were found to be positive for lyssavirus antigen; this presents an overall prevalence rate of 56.18 ...
Computerised analysis of standardised ultrasonographic images to monitor the repair of surgically created core lesions in equine superficial digital flexor tendons following treatment with intratendinous platelet rich plasma or placebo. The effectiveness of new therapies to treat tendon injuries is difficult to determine and is often based on semi-quantitative methods, such as grey level analysis of ultrasonographic images or subjective pain scores. The alternatives are costly and long-lasting end-stage studies using experimental animals. In this study, a method of ultrasonographic tissue characterisation (UTC), using mathematical analysis of contiguous transverse ultrasonographic images, was used for intra-vital monitoring of the healing trajectory of standardised tendon lesions treated with platelet rich plasma (PRP) or pla...
Environmental and demographic risk factors for poor welfare in working horses, donkeys and mules in developing countries. Over 85% of equids live in developing countries, where they are usually used for work. We aimed to identify environmental factors associated with potential welfare problems in working equids, helping target welfare interventions towards the most vulnerable animals. Over 5 years, non-invasive behavioural and physical data were collected from 5481 donkeys, 4504 horses, and 858 mules across nine developing countries. Hoof and limb problems were over 90% prevalent, and 85% of equids were thin. Older, thinner animals had the most problems, and species differences in susceptibility were found. Equid...
Could work be a source of behavioural disorders? A study in horses. Stress at work, as shown by a number of human studies, may lead to a variety of negative and durable effects, such as impaired psychological functioning (anxiety, depression...). Horses share with humans this characteristic of working on a daily basis and are submitted then to work stressors related to physical constraints and/or more "psychological" conflicts, such as potential controversial orders from the riders or the requirement to suppress emotions. On another hand, horses may perform abnormal repetitive behaviour ("stereotypies") in response to adverse life conditions. In the present st...
Faecal shedding and serological cross-sectional study of Lawsonia intracellularis in horses in the state of Minas Gerais, Brazil. Proliferative enteropathy, caused by the intracellular bacterium Lawsonia intracellularis, has been described in horses in Australia, the USA, Canada and European countries but has not been reported in Latin America. The prevalence of the disease in horses worldwide is unknown. Objective: To evaluate the presence of subclinical L. intracellularis infection in horses in the state of Minas Gerais, Brazil. Methods: A longitudinal study using serology and PCR for detecting antibodies (IgG) and shedding of L. intracellularis in faecal samples, respectively, was conducted using a total of 223 horses...
Acute phase response to surgery of varying intensity in horses: a preliminary study. To evaluate the postoperative inflammatory response of horses to elective surgery of varying intensity. Methods: Prospective longitudinal study. Methods: Horses referred to 2 hospitals for either arthroscopic removal of a unilateral osteochondritic lesion in the tibiotarsal joint (minimal surgical trauma, n=11), correction of recurrent laryngeal neuropathy by laryngoplasty and ventriculectomy (intermediate surgical trauma, n=10) or removal of an ovarian tumor by laparotomy (major surgical trauma, n=5). Methods: Horses had a thorough clinical examination every day. White blood cell (WBC) counts...