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Topic:Equine Health
Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Reduced levels of nitric oxide metabolites in cerebrospinal fluid are associated with equine protozoal myeloencephalitis. Equine protozoal myeloencephalitis (EPM) is a disease of horses that is primarily associated with infection with the apicomplexan Sarcocystis neurona. Infection with this parasite alone is not sufficient to induce the disease, and the mechanism of neuropathogenesis associated with EPM has not been reported. Nitric oxide (NO) functions as a neurotransmitter, a vasodilator, and an immune effector and is produced in response to several parasitic protozoa. The purpose of this work was to determine if the concentration of NO metabolites (NO(x)(-)) in the cerebrospinal fluid (CSF) is correlated with...
Importance of M-protein C terminus as substrate antigen for serodetection of equine arteritis virus infection. Equine arteritis virus (EAV), an enveloped positive-stranded RNA virus, is the prototype of the arterivirus group. In a previous paper (A. Kheyar, S. Martin, G. St.-Laurent, P. J. Timoney, W. H. McCollum, and D. Archambault, Clin. Diagn. Lab. Immunol. 4:648-652, 1997), we have shown that the unglycosylated membrane (M) protein, which is composed of 162 amino acids (aa), is a major target of equine antibody to EAV. In order to determine the antigenic regions of the M protein, the cDNA encoding the M protein of EAV was inserted into the procaryotic expression vector pGEX-4T-1 to produce recombin...
Contractile response of horse deep dorsal penile vein to histamine. The present investigation was designed to evaluate the effect of histamine on isolated rings of horse deep dorsal penile vein. Under precontracted or basal conditions, histamine evoked an endothelium-independent contraction. Preincubation of the vein rings with the selective H1 receptor antagonist, mepyramine, shifted the concentration-response curve for histamine and to the H1 receptor agonist 2-pyridylethylamine to the right in a competitive manner. Pretreatment with cimetidine, a specific H2 receptor antagonist, did not modify the pEC50 and maximal contraction of the histamine response. Cim...
The plasma level of triacylglycerols in horses fed high-fat diets containing either soybean oil or palm oil. The influence of dietary soybean oil versus palm oil on the plasma level of triacylglycerols was determined in a crossover experiment with four horses. Based on published data for humans and laboratory animals it was expected that a diet rich in unsaturated fatty acids in the form of soybean oil compared to saturated fatty acids in the form of palm oil would lower the plasma triacylglycerol level. The feeding of soybean oil versus palm oil for a period of four weeks did not change the level of plasma triacylglycerols in horses. Mean levels of triacylglycerol, free fatty acids and 3-hydroxybuty...
Experimental infection of horses with West Nile virus. A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt a...
Common vetch (Vicia sativa) for improving the nutrition of working equids in Campesino systems on hill slopes in Central Mexico. Campesino systems on hill slopes in Central Mexico rely on equids for multiple activities and have a problem in adequately feeding them. A participatory trial was conducted to evaluate the inclusion of common vetch in the traditional forage oat crop to improve its feeding value. An agronomic evaluation was undertaken by intersowing common vetch at 40 kg seed/ha with oats at 80-100 kg/ha in small plots, recording the yield and the chemical composition of the fresh forage in ten plots at harvest. The data were analysed as a completely random design, taking each farmer/plot as a treatment. A feed...
Comparison, characterization, and identification of proteases and protease inhibitors in epididymal fluids of domestic mammals. Matrix metalloproteinases are major fluid gelatinases. The testicular and epididymal fluids of ram, boar, and stallion were analyzed by means of one-dimensional and two-dimensional gelatin gel zymography. Five main gelatinolytic bands were revealed in the ram and at least seven were observed in the boar and stallion. These proteolytic bands showed regionalized distribution throughout the organs. The two main proteolytic activities at around 54-66 kDa retrieved in all three species were inhibited by EDTA and phenanthroline, indicating that they were metallo-dependent enzymes. The activity of some of the low-molecular-weight gelatinases was also dec...
In vitro development of horse oocytes reconstructed with the nuclei of fetal and adult cells. This study investigated the basic conditions required for the production of horse embryos by the transfer of the nuclei of fetal and adult fibroblast cells to enucleated oocytes. Cumulus-oocyte complexes were recovered from abattoir ovaries and matured in vitro in groups of 20-30 for 28-30 h in tissue culture medium 199 containing 20% v:v fetal bovine serum in coculture with equine oviduct epithelial cells. Fetal fibroblast cells (FFC) were derived from a 32-day-old Thoroughbred x Pony fetus, and adult skin fibroblast cells (SFC) were obtained from subdermal biopsies recovered from a 4-yr-old ...
[Keeping of horses in circus and show businesses]. The conditions under which horses are kept and the performance of acts in the circus ring may give rise to animal protection-relevant aspects for circus and show horses. A number of intolerable conditions under which horses are kept and procedures adopted for the work with circus and show horses are described. In addition, attention is drawn to monitoring methods capable of exposing the deplorable shortcomings of these businesses.
Exertional rhabdomyolysis in a 4-year-old standardbred filly. A young standardbred filly became stiff and uncomfortable after racing. A day later, creatine kinase, aspartate aminotransferase, and lactic dehydrogenase levels were markedly elevated. Exertional rhabdomyolysis was diagnosed. Limited exercise and a low carbohydrate, high fat diet were prescribed. Eight days later, the filly was raced again without consequences.
Suppression of meiosis by inhibitors of m-phase proteins in horse oocytes with low meiotic competence. Germinal vesicle (GV)-stage horse oocytes with diffuse chromatin are meiotically incompetent and degenerate in culture, whereas horse oocytes having condensed chromatin within the GV are meiotically competent. Degeneration of incompetent oocytes in culture may be related to premature GV breakdown, which could possibly be prevented by inhibition of m-phase protein activity. We examined the effects of 6-dimethylaminopurine (6-DMAP), butyrolactone and roscovitine on GV-stage horse oocytes. Culture in the presence of 2 mM 6-DMAP for 24 h suppressed meiosis (2% MI or MII compared with 38% for untre...
[Criminal acts against horses–phenomenology and psychosocial construct]. Since 1993 increasing numbers of violent crimes against horses were recorded in Germany. Meanwhile "Horse Ripping" is accepted as a new criminal phenomenon. It is defined as destructive acts with the aim to harm a horse or the acceptance of a possible injury of a horse, especially killing, maltreatment, mutilation and sexual abuse in sadomasochistic context. The study includes a complete situation report from 1993 to 2000, especially the development of the crime. Criminal events (N = 1035) were analysed about modus operandi, especially the specification of the injuries and regional distributio...
Equine estrogens induce apolipoprotein E and glial fibrillary acidic protein in mixed glial cultures. Premarin, which contains several equine estrogens, as well as estradiol (E2) as a minor component, is widely used for replacement therapy of estrogen deficits, but little is known of its direct actions on brain cells. In mixed glial cultures, apolipoprotein E (apoE) and glial fibrillary acidic protein (GFAP) are induced by estrogens. GFAP induction showed an inverted-U shape E2 dose response, with a maximum induction at 1 pM, whereas apoE mRNA induction was greatest at 100 pM. GFAP and ApoE mRNAs were induced by equine estrogens in the following order: E2=equilin>estrone>17 alpha-dihydro...
The C-terminal regions of the envelope glycoprotein gp2 of equine herpesviruses 1 and 4 are antigenically distinct. The unusual mucin-like high molecular mass (Mr) glycoprotein 2 (gp2) has only been described in the equid alphaherpesviruses, among which there is considerable antigenic cross-reactivity. Equine herpesvirus 1 (EHV-1) gp2 is cleaved into a highly glycosylated N-terminal subunit and a 42 kDa C-terminal cleavage product. In order to investigate their antigenic recognition by horses naturally infected with EHV-1 and/or equine herpesvirus 4 (EHV-4), the C-terminal cleavage product and high Mr gp2 were affinity purified. Cross-reactivity between EHV-1 and EHV-4 was observed for the high Mr gp2 using...
Osteoarthrosis of the antebrachiocarpal joint of 7 riding horses. Osteoarthrosis (OA) of the antebrachiocarpal joint from 7 riding horses is described. The horses were old mares and developed severe OA, with ankylosis in some of the joints. The lesions were bilateral, and the owners noticed the lameness in a late event. The cause of severe OA in these mares is not clear. The fact that OA was bilateral indicates that a single traumatic injury is unlikely as an etiologic factor. Considering the severe joint lesions it took long time before the horse-owners noticed the lameness. It is discussed if the threshold of pain is higher in the antebrachiocarpal joint c...
Sex steroids in serum of prepubertal male and female horses and correlation with bone characteristics. We used radioimmunoassay (RIA) to measure monthly serum levels of unconjugated and conjugated sex steroids (testosterone T, androstenedione A, estradiol E(2), and estrone E(1)) in 4 male and 4 female foals during their first year of life. Maximal production of sex steroids was detected from April to August with hormonal peaks, corresponding to the natural breeding season in adults. In males, only A levels were more steady. Total estrogens (unconjugated plus conjugated E(2) and E(1)) were the major steroids in immature males in contrast to adults. Estrogens generally peaked in young females bef...
Fetlock joint kinematics differ with age in Thoroughbred [was thoroughbred] racehorses. Fetlock joint kinematics during galloping in 2-, 3-, 4-, and 5-year-old Thoroughbreds in race training were quantified to determine if differences due to age could account for the observation that 2-year old Thoroughbred racehorses incur a high number of injuries to the bones and soft tissues in the distal forelimbs during training and at the outset of racing. Twelve Thoroughbred racehorses were videotaped in the sagittal plane at 250 frames/s during their daily galloping workout on a 7/8 mile sand-surface training track. Four galloping strides were recorded for each horse and subsequently dig...
Anatomic reference for computed tomography of the head of the foal. The purpose of this study was to produce an anatomic reference for computed tomography (CT) of the head of the foal for use by radiologists, clinicians, and veterinary students. The head from each of 2 foals, euthanized for reasons unrelated to head pathology, was removed and prepared for CT scanning. Using a third-generation CT scanner, 5-mm contiguous transverse images were acquired. The heads were then frozen and sectioned using a band saw, with the cuts matched as closely as possible to the CT slices. The anatomic sections were photographed and radiographed. The radiographs and anatomic ph...
Oxidative DNA damage induced by equine estrogen metabolites: role of estrogen receptor alpha. Excessive exposure to synthetic and endogenous estrogens has been associated with the development of cancer in several tissues. 4-Hydroxyequilenin (4-OHEN), a major metabolite of equine estrogens present in estrogen replacement formulations, has been shown to induce cytotoxic/carcinogenic effects. In the present study, we have found that 4-OHEN caused DNA damage in breast cancer cells, and cells that contain estrogen receptor alpha (S30) are more sensitive to 4-OHEN-mediated DNA damage as compared to estrogen receptor negative cells (MDA-MB-231). For example, concentration-dependent increases ...
Torque patterns of the limbs of small therian mammals during locomotion on flat ground. In three species of small therian mammals (Scandentia: Tupaia glis, Rodentia: Galea musteloides and Lagomorpha: Ochotona rufescens) the net joint forces and torques acting during stance phase in the four kinematically relevant joints of the forelimbs (scapular pivot, shoulder joint, elbow joint, wrist joint) and the hindlimbs (hip joint, knee joint, ankle joint, intratarsal joint) were determined by inverse dynamic analysis. Kinematics were measured by cineradiography (150 frames s(-1)). Synchronously ground reaction forces were acquired by forceplates. Morphometry of the extremities was perfo...
Cytokine induction in pulmonary airways of horses with heaves and effect of therapy with inhaled fluticasone propionate. Work in humans and laboratory animals has identified a central role for cytokines and chemokines in development and persistence of lower airway inflammation. The objectives of this study were to determine interleukin (IL)-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha induction in bronchoalveolar lavage (BAL) of control horses and horses with heaves both during remission and exacerbation of the disease, and to determine the effect of therapy with inhaled fluticasone propionate on the cytokine profile of horses with heaves. IL-1 beta an...
EHV-1 gene63 is not essential for in vivo replication in horses and mice, nor does it affect reactivation in the horse: short communication. The aim of this study was to investigate the role of immediate early gene (gene63) in the pathogenesis of equine herpesvirus 1 (EHV-1) acute and latent infections in equine and murine models. EHV-1 gene63 mutant virus (g63mut) along with EHV-1 (Ab4) was used for intracerebral and intranasal infection of 3 and 17-day-old mice. Both viruses were recovered at the same frequency from tissues after infection. Two Welsh ponies were infected via the intranasal route with each of the viruses. Acute infection was monitored by virus isolation from nasal swabs and peripheral blood leukocytes. Six weeks p...
Effects of racing on lymphocyte proliferation in horses. To measure the lymphocyte proliferation response in horses 12 to 16 hours after completion of a race. Methods: 8 Thoroughbreds that competed in 14 races and 3 control Thoroughbreds that did not race. Methods: Horses participated in races during the late afternoon or evening. Venous blood samples were collected on a morning before a race (1 or 2 days before the race or on the day of the race), on the afternoon of a race (40 to 60 minutes after the race), and on the morning of the day after a race (12 to 16 hours after the race). Lymphocyte proliferation responses and WBC count were measured in ...
Isolation, identification, and characterization of compounds from acer rubrum capable of oxidizing equine erythrocytes. To identify compounds in Acer rubrum that cause hemolysis or oxidation of equine erythrocytes and determine whether these toxins are found in other Acer spp. Methods: Equine erythrocytes. Methods: Washed erythrocytes were incubated with extracts and fractions of Acer spp that were separated by thin layer chromatography. Methemoglobin and hemolysis were measured spectrophotometrically. Compounds within Acer spp fractions associated with cell oxidation or hemolysis were identified by gas chromatography-mass spectrometry. Results: Erythrocytes incubated separately with either A. rubrum, A. saccha...
Age-related changes in lymphocyte subsets of quarter horse foals. To characterize changes in lymphocyte subsets over time in foals from birth to 18 weeks of age, accounting for differences among individuals, and to determine the effect of overnight storage of blood samples on foal lymphocyte subset concentrations. Methods: 8 healthy Quarter Horse foals from birth to 18 weeks of age. Methods: Blood samples were collected longitudinally from birth to 18 weeks of age and a CBC performed on each sample. The samples were stained for lymphocyte markers, either immediately or after overnight storage and analyzed by flow cytometry. Results: Total leukocytes, total l...
Placentitis, fetal pneumonia, and abortion due to Rhodococcus equi infection in a Thoroughbred. Rhodococcus equi is a rare cause of equine abortion. This report describes pyogranulomatous placentitis and fetal pneumonia in a case of abortion from a Thoroughbred mare. Numerous Gram-positive coccobacilli were noted histologically within macrophages in placental and pulmonary lesions. Rhodococcus equi was isolated in pure culture from the placenta, lung, liver, kidney, and stomach content. This is the first description of placentitis due to Rhodococcus equi infection in a horse.
Partial orbital rim resection, mesh skin expansion, and second intention healing combined with enucleation or exenteration for extensive periocular tumors in horses. Ocular and periorbital sarcoids and squamous cell carcinoma are common in equine practice. Extensive involvement of periorbital tissues often necessitates removal of the globe if the function of the eyelids can not be maintained with tumor removal alone. This report describes a modification of the standard enucleation or exenteration technique for cases in which there is insufficient skin to achieve primary closure following complete surgical excision. The caudal portion of the dorsal orbital rim is protuberant; partial excision with an osteotome facilitates skin closure by decreasing the size...
