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.
Gopinath G, Ford EJ.The hepatotoxic effect of oral halothane in the horse is increased by pretreatment with phenobarbitone or DDT but not by chlorpromazine. Phenobarbitone and DDT increase the activity of hepatic amidopyrine N-demethylase but chlorpromazine does not. Carbon disulphide protects the liver of the horse against halothane.
Ronda GJ, Gaastra W, Beintema JJ.The kinetic parameters Km, k+2 and k+2/Km of the pancreatic ribonucleases (EC 3.1.4.22) from cow, giraffe, horse, rat and lesser rorqual have been determined, using 2',3'-cyclic cytidine monophosphate and 2',3'-cuclic uridine monophosphate as substrates. No large differences were found between the activities of the five enzymes. The relative differences between the activities of the five enzymes are mainly due to differences in the rates of hydrolysis and not to differences in the affinities for the substrates.
Nett TM, Pickett BW, Seidel GE, Voss JL.Jugular venous blood was collected from 16 mares at daily intervals throughout the estrous cycle. Twelve of these mares were bred to fertile stallions. Of the twelve, four were palpated daily throughout the estrous cycle, four were palpated daily during estrus and four were not palpated. The remaining four mares were not palpated or bred and blood samples were collected at 6-h intervals during estrus. Serum was harvested from all blood samples by centrifugation. The serum samples were analyzed for luteinizing hormone (LH) and/or progesterone by radioimmunoassay. Levels of LH in serum increased...
Mackenzie RM, de Siger J, Parra D.Two strains of Venezuelan equine encephalitis (VEE) virus were examined for the ability to replicate in, as well as to produce death among donkeys. One, a low passage strain known as strain P676 was originally isolated from mosquitos in Venezuela. The other, strain V-38 was isolated from a horse brain in 1938 and had undergone an unknown number of laboratory passages; it is used extensively for the preparation of inactivated VEE vaccine. Both strains were found to be approximately equal in their ability to infect donkeys. However, a quantity as small as 50% hamster intraperitoneal infectious u...
Wilks CR, Studdert MJ.The immunological and virological status of 3 foals in respect of equine herpesviruses (EHV) was established and the foals were sequentially infected with EHV2, EHV3 and EHV1. Following experimental infection with EHV2, no clinical signs of disease were observed in any foal. The inoculation of EHV3 into the genital tract resulted in lesions of the mucous membrane and perineal skin that were considered typical of equine coital exanthema. Following intransal inoculation of EHV3 extensive ulceration and pustule formation on the nasal mucosa was observed by day 5 accompanied at day 7 by a profuse,...
Kotts C, Jenness R.Kappa-Casein-like proteins were isolated from the milks of cow, goat, reindeer, horse, rat, and rabbit. When treated with rennin, all of the isolated kappa-casein components yielded para-kappa-casein-like bands on gel electrophoresis. The rate of cleavage of these components with rennin was determined by measuring material soluble in trichloroacetic acid (macropeptide). The curves were characteristic of a limited, specific attack by rennin on these proteins. The goat and reindeer kappa-caseins were nearly as bovine kappa-casein, but the cleavage of horse, rat, and rabbit kappa-casein-like comp...
Tervit HR.Recent advances in reproductive physiology offer ways for exploiting superior, female cattle and for manipulating physiological events such as parturition. The techniques involved in these advances and their associated hazards are the subject of this review.
Serrano L, Lees P.The butyrophenone tranquilliser, azaperone, was administered intramuscularly to ponies in five series of experiments, using a dose level of 0-4 mg/kg once and 0-8 mg/kg four times. An excellent or good sedative effect was usually obtained with both dose levels, but the response was more consistent with the higher dose. The onset of sedation was apparent within 10 min of administration, the maximal effect usually occurring between 20 and 60 min while sedation was no longer apparent after 2 to 6 h. Body temperature was reduced in all animals for at least 2 h and respiratory rate was increased in...
Wilks CR, Coggins L.Twenty-two ponies were examined for serum-neutralizing (SN) antibody to equine herpesvirus type 1 and for in vitro lymphocyte transformation in the presence of viral antigen. Six ponies had undetectable levels of neutralizing antibody (titer less than 1:2) and had lymphocytes which did not respond in culture with viral antigen (stimulation index less than 2.0). Four ponies which had SN antibody to equine herpesvirus type 1 did not manifest lymphocyte transformation in vitro. The 12 remaining seropositive ponies had lymphocyte transformation with viral antigen in vitro (stimulation indexes from...
Palmer AC, Rossdale PD.A neuropathological investigation was carried out on the brains of 18 foals suffering from the neonatal maladjustment syndrome and results were compared with those obtained from the brains of nine foals dying from other causes. Necrosis of the cerebral cortex of an ischaemic nature was found in nine of the neonatal maladjustment foals, frequently accompanied by local haemorrhage. In three of this group of foals there was also necrosis in the diencephalon and brain stem. In the brains of the nine other affected foals there was haemorrhage in the cerebrum and sometimes in the brain stem and cere...
Bolton JR, Merritt AM, Cimprich RE, Ramberg CF, Streett W.The D-xylose absorption test was applied to clinically normal horses and to horses with signs of gastrointestinal disease. A dosage of 0.5 grams of xylose per kilogram of bodyweight was useful in detecting horses that absorbed the pentose abnormally. The clinical findings were correlated with gross and microscopic findings by biopsy and at necropsy. Gastrointestinal lesions associated with abnormal xylose absorption were classified as: 1) villous atrophy; 2) edema of the lamina propria or 3) necrosis of the lamina propria.
Kumar R, Sethi K, Gaur DK, Goyal SK, Kumar S, Jain S, Kumar S.Serodiagnosis of surra, caused by Trypanosoma evansi, is still based on native antigens purified from bloodstream form of T. evansi grown in rodents. In order to investigate prospective diagnostic possibilities as an alternative for native antigens, we cloned, expressed 26 kDa calflagin protein containing 218 amino acids from T. evansi (Indian Strain) in Escherichia coli. The potential of recombinant calflagin (rCLF) protein as diagnostic antigen was evaluated in immunoblot and indirect ELISA using experimentally infected equine serum samples from 0 to 84 days post infection. The antibodies a...
Gebhart W, Niebauer GW.The morphological substrates of pigmented and depigmented skin as well as the structural characteristics of spontaneously developing melanomas were revealed by clinical, light- and electron microscopic methods in gray horses (Lipizzaner breed) from the Vienna Spanish Riding School. On clinical investigations in a group of 31 older horses (more than 10 years old) 20 exhibited melanomas, whereas 23 younger animals (less than 10 years of age) had no evidence for visuable melanotic tumors. Concomitantly with the progressive graying of the hair a depigmentation of the skin was frequently observed. ...
Dumasia MC.The in vivo biotransformation of metoprolol tartrate in the thoroughbred racehorse was studied after administration of a single oral dose. Metoprolol and its basic and bifunctional phase I metabolites were isolated from urine and plasma using mixed mode solid phase extraction (SPE) cartridges. The isolates were derivatised as trimethylsilyl ethers and analysed by capillary column gas chromatography--positive ion electron ionisation and ammonia chemical ionisation mass spectrometry. Metabolism was primarily confined to the oxidative transformations of the p-(2-methoxy)ethyl substituent. Metopro...
Harkins JD, Robinson NE, Woods WE, Lehner AF, Smith MD, Gates RS, Fisher M, Tobin T.Clenbuterol, a beta2 agonist/antagonist, is the only bronchodilator approved by the US Food and Drug Administration for use in horses. The Association of Racing Commissioners International classifies clenbuterol as a class 3 agent, and, as such, its identification in post-race samples may lead to sanctions. Anecdotal reports suggest that clenbuterol may have been administered by intratracheal (IT) injection to obtain beneficial effects and avoid post-race detection. The objectives of this study were (1) to measure the pharmacological efficacy of IT dose of clenbuterol and (2) to determine the ...
Atwill ER, Mohammed HO, Lopez JW, McCulloch CE, Dubovi EJ.To locate counties within New York state with a high seroprevalence among the equine population, to determine host, management, and environmental factors that were associated with seropositivity to Ehrlichia risticii, and to determine evidence for arthropod- or helminth-mediated transmission of E risticii to horses. Methods: Cross-sectional study. Methods: A random sample of 3,000 of the 39,000 equine operations in New York state was selected, and 2,587 horses from 511 operations were tested. Methods: Blood samples were collected from horses and tested for seropositivity, using the indirect fl...
Golzari K, Kong Y, Reed SA, Posada-Quintero HF.The continuous monitoring of stress, pain, and discomfort is key to providing a good quality of life for horses. The available tools based on observation are subjective and do not allow continuous monitoring. Given the link between emotions and sympathetic autonomic arousal, heart rate and heart rate variability are widely used for the non-invasive assessment of stress and pain in humans and horses. However, recent advances in pain and stress monitoring are increasingly using electrodermal activity (EDA), as it is a more sensitive and specific measure of sympathetic arousal than heart rate var...
Haider W, Brehm W, Keller H.An apparently unilateral cryptorchid stallion was referred to the clinic with a history of colic. In the course of laparotomy an ileus caused by strangulation of the small intestine was found and the horse was euthanized because of poor prognosis. During autopsy strictures and ectasia of the jejunum were found as well as hermaphroditism along with male phenotype. The frequency of cryptorchidism in the case of intersexuality is discussed.
Jaeschke G, Rudolph R.The literature contains about 500 cases of equine leucosis, though the reports are deposited in a great number of journals and vary considerably concerning particular topics. During the last years there has been a remarkable increase of publications about this syndrome in the equine. The clinical leucosis key recommended by us has been confirmed in principle considering the latest literature. In about 70 individual symptoms which can be clinically observed in equine with leucosis 11 can be considered as main symptoms because of their frequency; they are again classified in primary (lymph node ...
Rouette J, Cockram MS, Sanchez J, MacMillan KM.A study of musculoskeletal injuries in Standardbred racehorses on Prince Edward Island was conducted to determine the incidence and risk factors for injury. Monthly information was collected from 10 trainers and 153 Standardbred horses over a 12-month period. Seventeen new injuries were identified in pacers, representing a horse level incidence risk of 23% and an incidence rate of injury of 2.19 per horse-month at risk. Forty-one percent of the injuries occurred during a race, 53% during training and 6% during jogging. Fourteen horses had experienced a previous injury and 3 of these horses exp...
Côté MA, Blum KM, Burd MA.During artificial insemination of horses, it is important to accurately estimate the number of spermatozoa in each insemination dose. However, little research exists regarding sources of spermatozoa loss during collection and artificial insemination. Therefore, spermatozoal losses were quantified in the dismount loss (187.6×10(6)±62.5×10(6)spermatozoa), gel fraction (179.8×10(6)±61.7×10(6)spermatozoa), and the collection receptacle (136.1×10(6)±26.9×10(6)spermatozoa). Spermatozoal losses were examined in the centrifuge tube (25.8×10(6)±2.1×10(6)spermatozoa), AI pipette during the a...
Barr AR.An objective radiological method of assessing the degree to which horses are conformationally 'back at the knee' (hyper-extended) is described. The effects on the measurements of variations in the direction of the incident X-ray beam and variations in weight bearing by the horse were assessed. A change from a lateromedial projection towards a plamaro-lateral-dorsomedial oblique projection consistently tended to reduce the observed degree of hyperextension of the carpus. Raising the contralateral limb to increase the load on the carpus had little effect on the measurements. The carpi of 21 thor...
Guthrie GP, Cecil SG, Kotchen TA.To assess the renin-aldosterone system in a large mammal, simultaneous morning activities of plasma renin and concentrations of aldosterone and cortisol were measured in 25 thoroughbred horses. Renin was relatively low in all horses (0.16 +/- 0.02 (S.E.M.) ng angiotensin I/ml per h), levels of aldosterone in plasma were 527 +/- 130 pmol/1 and levels of cortisol in plasma were 141 +/- 11 nmol/l. Levels of aldosterone were significantly correlated with levels of renin in all horses (r = 0.62, P less than 0.001) but not with those of cortisol, and renin was negatively correlated with age in male ...
Seltzer KL, Stover SM, Taylor KT, Willits NH.The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and met...
Tangyuenyong S, Nambo Y, Nagaoka K, Tanaka T, Watanabe G.Most thyroid hormone determinations in animals are based on immunoassays adapted from those used to test human samples, which may not reflect the actual values of thyroid hormone in horses because of the presence of binding proteins. The aims of the present study were i) to establish a novel radioimmunoassay (RIA) using a more simple and convenient method to separate binding proteins for the measurement of total thyroxine (T4) in horses and ii) to validate the assay by comparing total T4 concentrations in yearling horses raised in different climates. Blood samples were collected from trained y...
Doyle AJ, Saab ME, Lewis KM, McClure JT.An alcohol-based rub has been confirmed effective at reducing bacterial counts on equine skin. Skin sites with expected high bacterial burden have not been tested or has a comparison to a common protocol been performed. Objective: To determine if ethanol-based antisepsis reduces bacterial counts on the equine distal limb comparable to a current chlorhexidine scrub method and determine the most effective application technique for the product. Methods: Randomised trial. Methods: Forty-one horses were used in the study. By horse, each limb was randomly assigned to a treatment group: 5min scrub us...
Paik WK, Farooqui J, Gupta A, Smith HT, Millett F.The present observations are the continuation of our earlier study on the physicochemical mechanism of protein-lysine methylation. In this paper the electrophoretic behaviour (pI values) of two chemically modified horse heart cytochromes c at lysine-72 with trifluoromethylphenylcarbamoyl (neutral group) or carboxydinitrophenyl (acidic group) is compared with the enzymatically methylated cytochrome c. The results indicate that although both chemically modified cytochromes c have lower pI values than the unmodified cytochrome c, the enzymatic methylation appears to be much more efficient in lowe...
Stock KF, Distl O, Hoeschele I.Simulated data were used to determine the properties of multivariate prediction of breeding values for categorical and continuous traits using phenotypic, molecular genetic and pedigree information by mixed linear-threshold animal models via Gibbs sampling. Simulation parameters were chosen such that the data resembled situations encountered in Warmblood horse populations. Genetic evaluation was performed in the context of the radiographic findings in the equine limbs. The simulated pedigree comprised seven generations and 40 000 animals per generation. The simulated data included additive gen...
Cervantes CC, Brown MP, Gronwall R, Merritt K.Each of 5 healthy mares was given 5 consecutive IM injections of ceftiofur sodium (2 mg/kg of body weight; 50 mg/ml) at 12-hour intervals. Ceftiofur concentrations were measured serially in serum, synovial fluid, peritoneal fluid, and urine, and were measured in CSF and endometrial tissue after the fifth dose. Mean elimination rate constant was 0.354 +/- 0.101 h-1 and elimination half-life was 2.49 +/- 0.49 hour. Mean serum ceftiofur concentrations peaked approximately 1 hour after each injection. The highest mean ceftiofur concentration was 5.09 micrograms/ml at 1 hour after the fifth dose fo...
Whitcomb RW, Schneyer AL, Roser JF, Hughes JP.Using a LH radioligand receptor assay (RRA) previously validated for use in serum and an equine monoclonal RIA, we have distinguished a subset of subfertile stallions with an elevated RRA/RIA ratio. After purification of the active moiety by anion exchange chromatography and immunoprecipitation with the equine LH (eLH) monoclonal antibody, RRA activity remained in the supernatant. This activity was also recognized by a polyclonal LH antibody (GDN 15) with wide cross-species recognition. This active fraction was further purified by gel filtration chromatography and shown to displace labeled eLH...
Meier HP.In 1828, the Society of Swiss Veterinarians (GST) raised a prize question in regard to the symptoms, etiology and prophylaxis of polyarthritis in the foal. The treatise of Matthias Anker on this subject was treated with distinction and published in 1830. His statements answered both the questions to the clinical aspects and referred also to epidemiological, pathological, economical and ethical issues as well as husbandry and relations with the breeders. The comprehensive article of Anker in a lucid language and obliging views still finds great interest today, as the septicemia is one of the bi...
Dória RGS, Reginato GM, Hayasaka YB, Fantinato Neto P, Passarelli D, Arantes JA.Percutaneous decompression of the cecum is a procedure that could be considered for horses with cecal gas distension. The aim of this study was to identify complications such as peritonitis and clinically relevant peritonitis (CRP) after transabdominal cecal trocarization in healthy horses using a cattle trocar and a cecal needle. Mixed breed horses were assigned to three groups (n = 6): horses that underwent trocarization with a cecal needle (G1) or a cattle trocar (G2), and a control group (CG) without cecal trocarization. The same horses were used in each group, respecting a three-month was...
Spurlock GH, Landry SL, Sams R, McGuirk S, Muir WW.Plasma volume, extracellular fluid volume (ECFV), and total body water (TBW) were measured before and after endotoxin (Escherichia coli) administration in 6 conscious adult horses. Evan's blue dye, sodium thiocyanate, and antipyrine were the test substances used to estimate plasma volume, ECFV, and TBW, respectively. Pharmacokinetic analysis of plasma concentration vs time was used to determine changes in body fluid compartments. The pathophysiologic effects of endotoxin were monitored by clinical evaluation, blood chemical changes, and blood gas determinations. All horses became dyspneic with...
Marland A, Sarkar P, Leavitt R.A method for the extraction of diazepam and its metabolites (nordiazepam, temazepam, and oxazepam) from equine urine and serum and their quantitation and confirmation by liquid chromatography-tandem mass spectrometry is presented. Valium, a formulation of diazepam, was administered at a dose of 10 mg intramuscularly to four standard-bred mares. Diazepam is extensively metabolized in the horse to nordiazepam, temazepam, and oxazepam. Diazepam urinary concentrations were found to be less than 6 ng/mL. Nordiazepam was found to be mainly in its glucuronide-conjugated form and was measured out to a...
Driver AJ, Barr FJ, Fuller CJ, Barr AR.Tearing of the medial palmar intercarpal ligament (MPICL) has been recognised as a cause of lameness in the Thoroughbred, but diagnosis is difficult due to the nonspecific clinical signs, and can be achieved only by performing arthroscopy on the mid carpal joint (MCJ). It would be beneficial to be able to image the MPICL using ultrasonography to determine whether pathology is present in the ligament in order to aid diagnosis and prognosis. Objective: To determine whether the MPICL could be imaged using ultrasound from the dorsal aspect of the MCJ, and to describe the technique and normal ultra...
Janett F, Aebi L, Burger D, Imboden I, Hässig M, Kindahl H, Thun R.The objective of this study was to evaluate the effect of the non-steroidal anti-inflammatory drug (NSAID) vedaprofen (Quadrisol) on quality and freezability of stallion semen. Experiments were performed using 22 Franches Montagnes stallions from the National Stud in Avenches (Switzerland) randomly divided into a control and test group. Vedaprofen was given orally to all stallions of the test group at the recommended therapeutic dose (initial dose of 2mg/kg followed by 1mg/kg body weight every 12h) for 14 days. Control animals received the same amount of carrier substance. During treatment, bl...
Hernandez D, Yeo WM, Brooks MB, Ness SL, Divers TJ, Stokol T.OBJECTIVE To evaluate the effects of treatment of horses with standard platelet inhibitors on ex vivo inhibition of platelet activation by equine herpesvirus type I (EHV-I). ANIMALS II healthy adult horses. PROCEDURES In a double-blinded, placebo-controlled crossover study, horses were treated orally for 5 days with theophylline (5 mg/kg, q 12 h), pentoxifylline (10 mg/kg, q 12 h), clopidogrel bisulfate (4 mg/kg, q 24 h), acetylsalicylic acid (20 mg/kg, q 24 h), or placebo. Horses received all treatments, each separated by a 3-week washout period. Platelet-rich plasma was prepared from citrate...
Leach DH, Sprigings EJ, Laverty WH.Standard univariate and bivariate statistical methods and two multivariate methods, stepwise regression and factor analyses, were used to analyze 17 stride-timing measurements of 22 racing Thoroughbreds filmed at the beginning of races. All horses were in a right-lead transverse gallop. Data were extracted from frame-by-frame analysis of 16-mm film taken with a high-speed camera. The mean stride duration was 0.405 s and the mean stride frequency was 2.47 strides/s. Stride duration had a higher correlation to the suspension-phase duration (r = 0.864) than to stride-stance-phase duration (r = 0....
Harrington DD.1. The effects of feeding with a purified magnesium-deficient diet (--Mg, 7-8 mg Mg/kg) on horse foal blood serum and tissue concentrations of Mg, calcium and phosphorus were studied, and the results compared with histopathological findings. 2. Serum concentrations of Ca and P were unaffected by feeding with the --Mg diet, whereas serum Mg concentrations decreased from a mean initial (day o) concentration of 0.78 mmol/l to 0.53 mmol/l 7 d after foals were placed on the -Mg diet, and then continued to decrease at a slower rate. 3. Aorta concentrations of Ca and P, but not Mg, were positively co...
Barton CK, Hughes KL, Cowan C, Nout-Lomas YS, Nelson BB.A 21-year-old Quarter Horse mare presented with a chronic, progressively worsening left pelvic limb lameness of 3 weeks duration. The initial examination identified a consistent lameness at a walk. Neurological examination showed sensory and gait abnormalities consistent with left femoral nerve dysfunction. The horse minimally advanced the leg cranially and had a shortened stride length at the walk. During the stance phase, the heels of the left hind foot did not contact the ground and the horse quickly took weight off of the limb. Diagnostic imaging (ultrasound and nuclear scintigraphy) exami...
Materniak-Kornas M, Rożek W, Rola J, Osiński Z, Löchelt M, Kuźmak J.Equine foamy virus (EFVeca) is a foamy virus of non-primate origin and among the least-studied members of this retroviral subfamily. By sequence comparison, EFVeca shows the highest similarity to bovine foamy virus. In contrast to simian, bovine or feline foamy viruses, knowledge about the epidemiology of EFVeca is still limited. Since preliminary studies suggested EFVeca infections among horses in Poland, we aimed to expand the diagnostics of EFVeca infections by developing specific diagnostic tools and apply them to investigate its prevalence. An ELISA test based on recombinant EFVeca Gag pr...
