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Topic:Veterinary Research
Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Chronic tenosynovitis of the carpal extensor tendon sheaths in 15 horses. The history, clinical features, radiological findings, treatment and outcome of 15 horses with chronic tenosynovitis of the carpal extensor tendon sheaths are reported. The condition was seen most commonly in horses used for jumping and penetration of the tendon sheaths by thorns was the most common aetiology. Treatment involved surgical resection of the hyperplastic synovial membrane, and adhesions within the tendon sheath, with primary closure. When combined with early postoperative physiotherapy this was found to be an effective method of treatment. All horses in this series were not lame a...
The significance of routine radiographic findings with respect to subsequent racing performance and longevity in standardbred trotters. A retrospective cohort study was made of the racing performance of trotters which had been subjected routinely to radiography before they started training and racing. Sixty-one per cent (148) of the 243 horses, foaled in 3 consecutive years, had one or more abnormal findings categorised into 5 relevant groups based on radiography, of which osteochondrosis (OCD) was the most specific diagnosis. Parameters used to reflect racing performance were: proportion of horses starting in races, number of starts per year, earnings per year, earnings per start and racing longevity. No significant associati...
An age-related study of morphology and cross-link composition of collagen fibrils in the digital flexor tendons of young thoroughbred horses. The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance. Consequently, the association of age and collagen fibril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds up to and including three years of age ha...
Heart rate variability in the horse by ambulatory monitoring. Using a microprocessor controlled Ambulatory Monitoring System (AMS) developed by one of us (LvD), we have been studying the changes in and control of heart rate in the resting horse. The system provides us with InterBeat Intervals (IBI in milliseconds), motion sensing, and a time domain measure (mean successive differences: MSD) of heart rate variability for periods up to 72 hours. Thoracic impedance is also available but parameters for the equine chest are not currently available. The system is completely noninvasive, small, and carried on a surcingle worn by the subject. The equine subject ...
Characterisation of Australian isolates of Actinobacillus capsulatus, Actinobacillus equuli, Pasteurella caballi and Bisgaard Taxa 9 and 11. The objective of this work was to perform a comprehensive phenotypic characterisation of 16 isolates of bacteria previously identified as Actinobacillus equuli. Methods: The 16 isolates that had been obtained from Australian animals--15 from horses and one from a rabbit--were compared with reference strains of A equuli, A capsulatus, Pasteurella caballi and Bisgaard Taxa 9 and 11. Results: The characterisation study demonstrated that only nine of the isolates were A equuli. The other isolates were identified as A capsulatus (the isolate from rabbit), P caballi (one isolate), Bisgaard Taxon 11 ...
Effect of 19-norandrostenololylaurate on testicular growth in colts. The effect of anabolic steroid on testicular growth was investigated in 3 experiments. In experiment I, 500 mg of the anabolic steroid was given to 4 colts and 100 mg to another 4 colts, every 3rd week, starting at age 16 months and ending at age 24 months. Six colts served as controls. Both treatments decreased total scrotal width (TSW) within 6 weeks. Seasonal testicular growth during spring partly overcame the effect of steroid treatment. Cessation of anabolic steroid treatment was followed by testicular growth at the same time as TSW in untreated colts was decreasing by virtue of the effec...
Application of equine infectious anemia virus core proteins produced in a baculovirus expression system to serological diagnosis. Equine infectious anemia virus (EIAV) core proteins were obtained from a baculovirus expression system. Recombinant baculoviruses (rBVs) highly expressed the Gag precursor and p26 antigens in an rBV-infected Sf21 cell culture supernatant. Enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) were conducted using the expressed proteins to detect antibodies from experimentally infected horses. The expressed antigens showed low background levels, high specificity and sensitivity in ELISA and AGID. The results of the serological tests using the expressed antigens were ident...
Occurrence of Gasterophilus intestinalis and some parasitic nematodes of horses in Sweden. A survey was performed on the occurrence of some internal parasites in 461 horses (1-30 years old) slaughtered from October 1992 to September 1993 at the Linköping abattoir in central Sweden. Macroscopical examination was carried out specifically for parasites of the tear ducts and conjunctival sacs of the eyes, and of selected parts of the alimentary tract and cardio-vascular system. The following parasites were found in selected parts of the large intestine: encapsulated cyathostome larvae (in 35.6% of the horses), and mature strongyle worms (17.4%); in the stomach: Gasterophilus intestinal...
Survey of diplomates of the American College of Veterinary Internal Medicine and the American College of Veterinary Surgeons regarding clinical aspects and treatment of endotoxemia in horses. A questionnaire designed to elicit information concerning prevalence, underlying causes, diagnosis, prevention, treatment, and complications of endotoxemia in horses was mailed to diplomates of the American College of Veterinary Internal Medicine and the American College of Veterinary Surgeons who identified themselves as equine practitioners. Gastrointestinal tract compromise, conditions associated with foaling, and grain overload were reported to be the most common clinical conditions that led to endotoxemia. Most of the respondents diagnosed endotoxemia on the basis of the following clinica...
Flexion test of the metacarpophalangeal and interphalangeal joints and flexion angle of the metacarpophalangeal joint in sound horses. This paper describes the application of a measuring device 'Flextest' to control the effect of traction force and traction time during flexion tests of the distal limb joints of the forelimbs. The optimal force for a flexion test is 100 N, over 1 min. A higher force (150 N) was not harmful. A slightly positive flexion response (100 N/1 min) in a horse with no other clinical signs or radiographic abnormalities is not of clinical significance. Individual left and right flexion and extension angles are almost identical and do not depend on age. Stabled horses which have been rested or horses rest...
Medroxyprogesterone acetate antagonizes inhibitory effects of conjugated equine estrogens on coronary artery atherosclerosis. Although estrogen replacement therapy is associated with reduced risk of coronary heart disease and reduced extent of coronary artery atherosclerosis, the effects of combined (estrogen plus progestin) hormone-replacement therapy are uncertain. Some observational data indicate that users of combined hormone replacement consisting of continuously administered oral conjugated equine estrogens (CEE) and oral sequentially administered (7 to 14 days per month) medroxyprogesterone acetate (MPA) experience a reduction in risk similar to that of users of CEE alone. However, the effects of combined, con...
Detection of an antigenic protein of Leptospira interrogans which shares epitopes with the equine cornea and lens. A protein epitope which is involved in an antigenic relationship between equine ocular tissues and Leptospira interrogans was detected in homogenates of the bacterium. The antigenic determinant was harboured on a peptide structure which was shown to be sensitive to the action of denaturing and reducing agents by means of Western blotting. The outer surface of the leptospires appeared to be free of this epitope as was proved by dot-blot and electron microscopic studies.
Distribution and relevance of equine herpesvirus type 2 (EHV-2) infections. Equine herpesvirus type 2 (EHV-2) is a slow-growing, cytopathogenic gammaherpesvirus, which is suggested to be ubiquitous in the equine population. However, its precise role as a pathogen and its tissue tropism remains uncertain. To estimate the prevalence of EHV-2 in Germany and to investigate the possible pathogenicity of the virus, peripheral blood leucocytes (PBL) from 172 horses were examined for EHV-2 DNA by a sensitive and specific nested PCR based on the EcoRI-N genomic fragment and by classical cocultivation. PBL samples from 51% of the horses were positive by PCR and virus was isolat...
Architecture and the division of labor in the extensor carpi radialis muscle of horses. The extensor carpi radialis muscle of the horse is deceptive at first appearance. It has a fusiform shape similar to other forearm extensor muscles. The fiber arrangement also appears long and relatively parallel. However, it may contain two or more compartments that correlate with differing functional roles. Histochemical and immunocytochemical analysis of proximal and distal regions of the muscle (n = 9) demonstrate that the proximal portion of the muscle is composed of a mean of 13% type I, presumed slow twitch, and 61% type IIb, presumed fast twitch fibers. In contrast, the distal compartm...
Laparoscopic abdominal anatomy of foals positioned in dorsal recumbency. Eleven foals (nine cadavers and two anesthetized) positioned in dorsal recumbency were examined to describe normal abdominal anatomy viewed by laparoscopy. The foals ages ranged from 1 to 150 days. Insertion sites were selected for a Verres needle, laparoscope and instrument portals to avoid trauma to the umbilical structures. The abdominal cavity was insufflated to a pressure of 10 to 12 mm Hg using an automatic carbon dioxide insufflator. Laparoscopic examination allowed excellent observation of the umbilical structures, the bladder, the genital tract, the inguinal area, the liver and segmen...
Characterization of horse (Equus caballus) immunoglobulin mu chain-encoding genes. Horse (Equus caballus) immunoglobulin mu chain-encoding (IgM) variable, joining, and constant gene segments were cloned and characterized. Nucleotide sequence analyses of 15 cDNA clones from a mesenteric lymph node library identified 7 unique variable gene segments, 5 separate joining segments, and a single constant region. Based on comparison with human sequences, horse variable segments could be grouped into either family 1 of immunoglobulin (Ig) clan I or family 4 of Ig clan II subclan IV. All horse sequences had a relatively conserved 16 base pair (bp) segment in framework 3 which was reco...
[Poisoning of horses by the bark of the false acacia (Robinia pseudoacacia)]. The present study describes the poisoning due to Robinia pseudoacacia in two horses. One of the horses showed mainly intestinal symptoms such as decreased intestinal motility and obstipation of the pelvic flexure. In the second animal central nervous symptoms were predominant. It showed intermittent phases of somnolence alternating with phases of excitation and head pressing. In addition mydriasis and a lacking menace response could be observed. Sensation to the head and the spinal reflexes were reduced. Symptomatic treatment was initiated in both animals and recovery occurred within 2 days.
Identification, cloning and sequence analysis of the equine adenovirus 1 hexon gene. Based on sequence homology with human adenovirus 2 (HAdV2), the hexon gene of equine adenovirus 1 (EAdV1) was identified. HindIII restriction fragments containing the hexon and other viral genes were cloned into the plasmids pUC19 and pBlueScript SK(-) and sequenced. The nucleotide sequence of the hexon gene was completely determined and partial sequence data were obtained for seven other EAdV1 genes. Amino acid (aa) sequence comparison with published adenovirus (AdV) proteins identified the genes for the IIIa, penton, pVII, PVI, 23K proteinase, DNA binding and 100K proteins. The eight EAdV1 g...
Adaptation of equine herpesvirus 1 to unnatural host led to mutation of the gC resulting in increased susceptibility of the virus to heparin. Heparin extensively inhibited infection of MDBK cells by equine herpesvirus 1 (EHV-1) strains adapted to bovine cells or hamsters, while the reagent merely reduced infectivity of strains passaged only in equine cells. The gC of two strains adapted to non-equine cells seemed to have higher affinity for heparin, although the reagent bound to both the gC and gB of all strains tested. Amino acid substitutions of the gC of the EHV-1 strains adapted to non-equine cells converged on the hydrophilic regions, amino acid residues 92 to 175, resulting in the glycoprotein becoming more cationic. These res...
Immunoepidemiology of the equine tapeworm Anoplocephala perfoliata: age-intensity profile and age-dependency of antibody subtype responses. The equine intestinal cestode Anoplocephala perfoliata has been the subject of recent epidemiological and immunological studies because of its suspected association with intestinal disease in the horse. We have previously shown that the IgG(T) subtype antibody response to the 12/13 kDa component of the parasite excretory/secretory (E/S) antigen is positively correlated with parasite intensity. In this study, we utilize that correlation to examine the changes in natural infection intensity with age. Infection intensity based on IgG(T) responses showed a triphasic age-dependency pattern with pea...
[Animal systemic iron sources utilized in vitro by staphylococci]. Under iron-restricted conditions staphylococcal strains could utilize in vitro several animals body iron sources in form of bovine haemoglobin, hemin, lactoferrin and transferrin, ovotransferrin, horse myoglobin ferritin and cytochrome C. Spectrum of utilized iron sources was not dependent on species affiliation and kind of siderophores system. Strains isolated from clinical materials utilized largest spectrum of animal iron body sources.
Comparison of racing performance before and after treatment of incomplete, midsagittal fractures of the proximal phalanx in standardbreds: 49 cases (1986-1992). To assess the effect of incomplete, midsagittal fractures of the proximal phalanx (P1) on racing performance in Standardbreds. Methods: Retrospective cohort study. Methods: 49 Standardbred horses admitted to the George D. Widener Hospital for Large Animals between July 1986 and December 1992 with a definitive radiographic diagnosis of an incomplete, midsagittal fracture of P1 and a known method of treatment. Methods: Performance index and racing time were compared before and after diagnosis and treatment of fracture, using ANOVA that controlled for the effects of horse, gender, age, track leng...
Quantitative two-dimensional echocardiography in the horse: a review. Quantitative two-dimensional echocardiography (2DE) was introduced into equine cardiology in the early 1990s. At first, linear and area dimensions and left ventricular volume were validated by the comparison of parameters determined during in vitro 2DE and autopsy measurements. Based on these studies, tomographic planes and intracardiac reference points for in vivo measurements were established and 2DE values have been determined for healthy adult horses by various authors. These data were similar to each other and proved to be comparable with M-mode echocardiography measurements. However, dif...
Atrial natriuretic peptide and C-type natriuretic peptide do not acutely inhibit the release of adrenocorticotropin from equine pituitary cells in vitro. It has been suggested that atrial natriuretic peptide (ANP) is the long-sought inhibitor of corticotropin (ACTH) secretion, but the evidence is conflicting. We have examined the effect of ANP and C-type natriuretic peptide (CNP) on the secretion of ACTH by perifused equine pituitary cells in an in vitro milieu intended to mimic the in vivo milieu in the horse. Corticotropin-releasing hormone (20 pM) and cortisol (0 or 100 nM) were perifused continuously and 7 pulses of arginine vasopressin (AVP; 10 nM) applied for 5 min at 30-min intervals. ANP (1 nM) or CNP (1 nM) were perifused continuously ...
Relationship between endometrial oxytocin receptors and oxytocin-induced prostaglandin F2 alpha release during the oestrous cycle and early pregnancy in pony mares. The effect of transcervical endometrial biopsy on the concentrations of plasma immunoreactive oxytocin and 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) was studied in 18 pony mares on days 8, 12 and 14 after ovulation, days 12 and 14 of early pregnancy and at oestrus. Five biopsy specimens were taken within 15 min and consecutive specimens from each mare were pooled two (A) and three (B) together for measurement of the number of oxytocin receptors. Blood samples were collected at intervals of 5 min for 15 min beginning just before the initial biopsy. Biopsy procedure elicited prompt oxy...
Electrically induced blink reflex in horses. The electrically induced blink reflex was studied electromyographically in 21 healthy adult, detomidine-sedated horses. Using surface electrodes, the supraorbital nerve was electrically stimulated at the supraorbital foramen. The responses were recorded from the ipsilateral and contralateral orbicularis oculi muscles with concentric needle electrodes inserted in the lateral aspect of the ventral eyelids. Ipsilateral and contralateral recordings were made on successive stimulations of the same side of the face, maintaining a constant stimulus intensity. The electromyographically recorded respon...
Fibronectin concentrations correlate with ovarian follicular size and estradiol values in equine follicular fluid. The amounts of total protein, albumin, fibronectin, alpha 2-macroglobulin (alpha 2-M), immunoglobulin G, ceruloplasmin and antithrombin were determined in fluids collected from 53 preovulatory equine follicles and compared with the contents of estradiol-17 beta, progesterone and androstenedione, with follicle size and the amounts of the equivalent proteins in normal equine plasma. The concentration of fibronectin and the fibronectin/albumin ratios increased significantly with follicle size and with follicular estradiol levels. The alpha 2-M levels and alpha 2-M/albumin ratios correlated with f...
Equine synovial villi: distinctive structural organization of vasculature and novel nerve endings. The structural arrangement and cellular distribution of endothelial and lining cells of the synovial villi were studied in the equine palmar/plantar recess of the metacarpo- and metatarsophalangeal joints by light microscopy and electron microscopy. The extent and distribution of blood vessels varied with villous shape and length. The majority of vessels formed concentric circles in cross and longitudinal sections and probably are arranged in a convoluted, spiral or helical pattern. The villi do not contain smooth muscle cells or typical capillaries as observed in other organs. Under the elect...
