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.
Phumoonna T, Muscatello G, Chicken C, Gilkerson JR, Browning GF, Barton MD, Heuzenroeder MW.A total of 227 field samples from naturally exposed foals aged between 3 weeks and 6 months were used in an evaluation of a peptide-based enzyme-linked immunosorbent assay (ELISA) for diagnosis of Rhodococcus equi infection. A biotinylated peptide derived from the virulence-associated protein A (VapA) of R. equi, a horse pathogen, was synthesized and designated as PN11-14. The peptide corresponds to the N-terminal B-cell epitope TSLNLQKDEPNGRASDTAGQ of the VapA protein. Based upon a serum immunoglobulin (Ig)G titre of 512 as a positive cut-off value for the R. equi infection, the ELISA provide...
Archer DC, Barrie Edwards G, Kelly DF, French NP, Proudman CJ.Idiopathic focal eosinophilic enteritis (IFEE) is a rare disease in the horse and few cases have been reported in the literature. The objective of this paper was to describe the clinical, surgical, histological features and post-operative progress of 12 horses with IFEE, a disease that had not been identified in the authors' hospital population prior to 2000. Diagnosis of IFEE was made at laparotomy and confirmed by histological examination of resected abnormal small intestine. In all 12 horses colic was associated with jejunal obstruction involving visibly striking and palpably thickened sero...
Laan TT, Bull S, Pirie RS, Fink-Gremmels J.Cyclic AMP elevating agents have been shown to exhibit anti-inflammatory properties in addition to functions such as bronchodilation. The aim of this study was to investigate this dual action of clenbuterol (CB; Ventipulmin) on horses affected with recurrent airway obstruction (RAO). Seven RAO susceptible horses received inhalation challenges with aerosolised lipopolysaccharide (LPS), hay dust suspension (HDS) and Aspergillus fumigatus antigen (AF) with and without prior treatment with intravenous CB. Data showed that CB exerted significant beneficial effects on lung function, total cell count...
Léon A, Pronost S, Tapprest J, Foucher N, Blanchard B, André-Fontaine G, Laugier C, Fortier G, Leclercq R.Studies were carried out to determine the cause of death in a prematurely born Thoroughbred foal that died 24 hours after birth. Necropsy revealed gross lesions suggestive of septicemia. A commercial Leptospira polymerase chain reaction (PCR) assay designed to specifically amplify the hemolysis-associated protein 1 (hap1) gene present only in pathogenic Leptospira strains detected the presence of Leptospira DNA in various tissues of the foal. Histologic examination of lung, liver, kidney, and myocardium revealed numerous spirochetes in Warthin-Starry-stained tissue sections. Results of PCR ana...
O'Rourke BA, Dennis JA, Healy PJ.Improvements to restriction fragment length polymorphism (RFLP)-based genotyping assays currently used for detection of mutations responsible for bovine ferrochelatase and myophosphorylase deficiencies, and equine hyperkalemic periodic paralysis (HYPP) are described. Reports of sporadic inhibition of restriction enzyme activity suggest a critical factor in RFLP-based genotyping assays should be assurance that restriction enzymes perform to specification with every sample. The RFLP genotyping assays that use either a mismatched recognition sequence in one or both of the oligonucleotides, or inc...
Kankavi O, Ata A, Gungor O.The presence of surface-active material in the lung alveolus has been known for several decades as being essential for normal lung function. Surfactant is essential for reducing the surface tension at the alveolar air-liquid interface. Pulmonary surfactant is composed of 90% lipids and 10% proteins. There are four non-serum proteins surfactant protein-A (SP-A), surfactant protein-B (SP-B), surfactant protein-C (SP-C) and surfactant protein-D (SP-D) named in chronologic order of discovery. Lung SP-A and SP-D belong to a family of collagen-containing C-type lectin family called collectins. The h...
Breathnach CC, Sturgill-Wright T, Stiltner JL, Adams AA, Lunn DP, Horohov DW.The increased vulnerability of foals to specific pathogens such as Rhodococcus equi is believed to reflect an innate immunodeficiency, the nature of which remains poorly understood. Previous studies have demonstrated that neonates of many species fail to mount potent Th1 responses. The current research investigates the ability of circulating and pulmonary lymphocytes of developing foals to produce interferon gamma (IFNgamma). Peripheral blood mononuclear cells (PBMC) were prepared from up to 10 horse foals at regular intervals throughout the first 6 months of life. Bronchoalveolar lavage (BAL)...
Pagl R, Aurich JE, Müller-Schlösser F, Kankofer M, Aurich C.A problem of semen extenders based on milk or egg yolk is the fact that these biological products consist of a variety of substances. Extenders containing only components with clearly protective effects on spermatozoa would thus be an advantage. In this study, we have compared the effects of an extender containing defined caseinates and whey proteins only (EquiPro, defined milk protein extender) with skim milk extender on equine spermatozoa during cooled storage. The defined milk protein extender was used with and without the antioxidant N-acetyl cysteine (NAC). In a second experiment, semen w...
Huang X, Xuan X, Yokoyama N, Katayama Y, Anzai T, Igarashi I.Two enzyme-linked immunosorbent assays (ELISA) with recombinant protein as antigens were evaluated by comparison with the indirect fluorescent antibody tests (IFAT) for the detection of specific antibodies to Babesia caballi and Babesia equi, respectively in 380 sera from experimentally infected, uninfected, and field horses. The high concordances of 92.4% (351/380) and 98.2% (373/380) between ELISA and IFAT for B. caballi and B. equi, respectively suggest that ELISA, especially for B. equi infection, could be alternative to the corresponding IFAT for serodiagnoses of equine piroplasmosis, alt...
Kankavi O, Ata A, Akif Ciftcioglu M.The presence of surface-active material in the lung alveolus has been known for several decades as being essential for normal lung function. The host defense and controlling inflammatory processes of the lung are the major functions of SP-A and SP-D. SP-A and SP-D were originally demonstrated in alveolar type II cells, but recent studies have shown extrapulmonary expression of SP-A and SP-D indicating systemic roles of these proteins. Present study describes the presence of SP-A and SP-D in the stallion genital tract, prepuce, prostate, testis, and seminal vesicle using Western blotting and im...
Eckert J, Ossent P.A 14-year-old horse (imported to Switzerland from Ireland 8 years earlier) showed signs of chewing muscle atrophy. A severe chronic myositis, caused by numerous immature and mature female nematodes, was diagnosed in muscle samples obtained by biopsy and subsequently at necropsy. Most of the nematodes had invaded muscle fibres of the masseter, root of the tongue and anterior breast, only a few were found in the intermuscular interstitium. Isolated nematodes and parasite sections were clearly different from muscle larvae of Trichinella spp. but showed morphological similarities to Haycocknema pe...
Leeb T, Vogl C, Zhu B, de Jong PJ, Binns MM, Chowdhary BP, Scharfe M, Jarek M, Nordsiek G, Schrader F, Blöcker H.In an effort to increase the density of sequence-based markers for the horse genome we generated 9473 BAC end sequences (BESs) from the CHORI-241 BAC library with an average read length of 677 bp. BLASTN searches with the BESs revealed 4036 meaningful hits (E <or= 10(-5)) in the human genome that provide useful markers for the human-horse comparative map. The 4036 BLASTN hits allowed the anchoring of 3079 BAC clones to the human genome, on average one corresponding equine BAC clone per megabase of human DNA. We used the BLASTN anchored BESs for an in silico prediction of the gene content an...
Maes A, Baert K, Croubels S, De Clercq D, van Loon G, Deprez P, De Backer P.A rapid method for the quantification of amiodarone and desethylamiodarone in animal plasma using high-performance liquid chromatography combined with UV detection (HPLC-UV) is presented. The sample preparation includes a simple deproteinisation step with acetonitrile. In addition, a sensitive method for the quantification of amiodarone and desethylamiodarone in horse plasma and urine using high-performance liquid chromatography combined with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) is described. The sample preparation includes a solid-phase extraction (SPE) with a SCX c...
Millar H.A 6-month-old filly was presented with unilateral epistaxis. Based on clinical signs, endoscopic examination, and postmortem examination, guttural pouch mycosis was diagnosed. The young age of the filly and the fact that this was the 2nd diagnosis of guttural pouch mycosis on this farm was unusual. Mycose de la poche gutturale chez une pouliche de 6 mois. Une pouliche âgée de 6 mois a été présentée pour épistaxis unilatérale. En tenant compte des signes cliniques, de l’examen endoscopique et de l’examen post-mortem, un diagnostic de mycose de la poche gutturale a été posé. Le je...
Cobbold S, Holmes M, Willett B.There is now a wide range of immunological reagents that can be used in the diagnosis and treatment of diseases in the companion animals (dogs, cats and horses). Many of these diseases are the veterinary equivalents of human conditions, and may therefore provide good models to study basic pathogenic mechanisms.
van der Velden MA, Klein WR.During a 3-year period 21 horses were surgically treated because of large abdominal wall defects. In each case the defect was bridged with a polypropylene mesh, which was placed on the outside of the hernial ring. This was in contrast with the technique for mesh herniorrhaphy generally described in human and veterinary literature, in which the mesh is always implanted on the inside of the hernial ring. One horse was destroyed on the first postoperative day because of postanaesthetic myelomalacia. Surgical repair as described was successful in 18 patients. Recurrence of herniation occurred in t...
Watney GC, Jordan C, Hall LW.The effects of halothane, enflurane and isoflurane on bronchial calibre were investigated in five anaesthetized ponies using a computer-aided forced airflow oscillation technique to derive specific lower airways conductance (s.Glaw) and expiratory reserve volume (ERV). All the agents tended to increase s.Glaw (indicating bronchodilatation), but ERV was reduced by halothane and enflurane, and increased by isoflurane. It was concluded that the effects of these agents on bronchomotor tone were similar to those which occur in man. However, the reasons for the differences in their effects on ERV co...
Snook ER, Wakamatsu N.A 17-year-old, Thoroughbred mare was presented for necropsy with a large, invasive oral mass determined via immunohistochemistry to be a soft tissue sarcoma of neural origin. Oral sarcomas are rare in veterinary medicine, and to the authors' knowledge, this is the first oral sarcoma of neural tissue origin reported in a horse.
Davis JL, Marshall JF, Papich MG, Blikslager AT, Campbell NB.The purpose of this study was to determine the pharmacokinetics of deracoxib following oral administration to horses. In addition, in vitro equine whole blood cyclooxygenase (COX) selectivity assays were performed. Six healthy adult horses were administered deracoxib (2 mg/kg) orally. Plasma samples were collected prior to drug administration (time 0), and 10, 20, 40 min and 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 h after administration for analysis with high pressure liquid chromatography using ultraviolet detection. Following PO administration, deracoxib had a long elimination half-life (t(...
Nixon AJ, Pool RR.Osteochondral fragments from the axial proximoplantar/proximopalmar region of the proximal phalanx were removed from 38 joints in 30 horses. Ninety-three percent of the horses were Standardbreds, and 28 of the 30 had a low-grade lameness. All but 1 of the horses had hind limb involvement. A total of 43 fragments were removed. Most (71%) of the fragments involved the medial aspect of the joint and had to be dissected from a covering of synovial tissue. Histologically, the circumference of most fragments consisted of a transition zone at the attachment of the joint capsule, a region of nonarticu...
Hunter JO.Irritable bowel syndrome (IBS) in man is not a single entity but has several causes. One of the most common forms has similarities with colic and laminitis in horses. Undigested food residues may pass from the small intestine into the colon where bacterial fermentation produces chemicals that lead to disease. In horses the consequences may be disastrous, but in healthy humans such malabsorption may not be harmful. After events such as bacterial gastroenteritis or antibiotic treatment, an imbalance of the colonic microflora with overgrowth of facultative anaerobes may arise, leading to malferme...
Deprez P, Vercruysse J.The results of the treatment with moxidectin or ivermectin of 20 horses with clinical cyathostominosis were studied during a 3-week observation period. Both treatments were effective in completely eliminating larvae from the faeces within 1 or 2 weeks, but no significant improvement in body weight or clinical parameters could be demonstrated over the observation period. The poor short time results of the treatment support the need for an adequate prevention of cyathostominosis in horses.
Bryant CE, Thompson J, Clarke KW.Medetomidine was administered to sheep and horses at a dose rate of 5 microg kg(-1) (i.v.). Heart rate and blood pressure were recorded. Medetomidine induced bradycardia and a biphasic blood pressure response consisting of a transient hypertension followed by hypotension. Administration of prazosin (an alpha1 adrenoceptor antagonist; 100 microg kg(-1), i.v.) had no effect on the cardiovascular response to medetomidine (5 microg kg(-1), i.v.), but inhibited the cardiovascular response of methoxamine (an alpha1 adrenoceptor agonist; 75 microg kg(-1), i.v.). L-659,066 (an alpha2 adrenoceptor anta...
Bundgaard L, Jacobsen S, Dyrlund TF, Sørensen MA, Harman VM, Beynon RJ, Brownridge PJ, Petersen LJ, Bendixen E.The aim of this study was the development of a quantitative assay that could support future studies of a panel of acute phase proteins (APPs) in the horse. The assay was based on a quantification concatamer (QconCAT) coupled to selected reaction monitoring methodology. Thirty-two peptides, corresponding to 13 putative or confirmed APPs for the Equus caballus (equine) species were selected for the design of a QconCAT construct. The gene encoding the QconCAT was synthesized and expressed as an isotope-labeled chimaeric protein in Escherichia coli. The QconCAT tryptic peptides were analyzed on a ...
Piuko K, Bravo IG, Müller M.In the present study we describe the isolation and characterization of putative equine granzyme B for which we propose the designation 'eqGrzmB'. Sequence analysis revealed characteristic features of a GrzmB protease such as the presence of a signal (leader-) peptide and an activation di-peptide. The isolated eqGrzmB is functionally active when expressed in human or in insect cells. Furthermore, exchange of any of three putative active site amino acids, which are highly conserved along granzyme B enzymes, led to a complete loss of enzymatic activity in the newly identified eqGrzmB. Phylogeneti...
van Doorn DA, van der Spek ME, Everts H, Wouterse H, Beynen AC.Literature data show conflicting results on the effect of feeding high calcium (Ca) levels on phosphorus (P) digestibility in ponies. None of the studies reported involved a dose response as to the effect of Ca intake on apparent P digestibility while keeping P intake constant. Thus, the influence of high dietary Ca level on apparent P digestibility was studied in balance trials by feeding six mature ponies three different Ca levels against a constant P intake. The ponies received 148, 316 and 535 mg Ca/kg BW/day with the low, intermediate and high Ca diet. Phosphorus intake was approximately ...
Mantovani R, Rora A, Falomo ME, Bailoni L, Vincenti L.The aims of this study were to compare glycerol (G) at customary concentrations and ethylene glycol (EG) as cryoprotectants for stallion semen in a skimmed milk (SM) extender, to test different EG concentrations and to compare the results of manual and computerized analysis with the hypoosmotic swelling (HOS) test. Ejaculates from two stallions were collected over 3 weeks (6 ejaculates per stallion), diluted in a SM based extender, divided into 4 fractions, centrifuged and diluted again to a concentration of 100 x 10(6) mL(-1) progressive motile spermatozoa (PMS) in addition with the cryoprote...
Meyer H, Hübert PH.The production and differentiation of monoclonal antibodies (mabs) against the Rac-H strain of EHV-1 used as an attenuated live vaccine to prevent rhinopneumonitis and abortion is described. Seven different antigenic sites were detected by the 15 mabs produced. EHV-1 specific mabs as well as EHV-1 and -4 common mabs could be established, allowing easy typing of EHV isolates. One mab recognized the vaccine strain only. This reaction was used to investigate a possible involvement of the vaccine strain in cases of abortion. Common antigenic determinants with EHV-1,-3,-4 and BHV-1 could also be de...
Vanderwall DK.Tremendous progress has been made in the development of assisted reproductive techniques that may enhance the reproductive efficiency of the horse. However, techniques that involve the manipulation of oocytes and/or embryos may themselves be detrimental to embryo viability and subsequent development. Therefore, an objective method of assessing viability of embryos before and/or after oocyte/embryo manipulation is desirable. At this time, morphologic evaluation is the most widely used method of determining the viability of equine embryos. Although morphologic assessment of embryo quality will n...
Murray RC, Dyson SJ, Weekes JS, Branch MV, Hladick S.Bone-phase scintigraphy is sensitive to the dynamic process of bone modeling and remodeling, which may be adaptive or pathologic. Our knowledge of normal patterns of radiopharmaceutical uptake (RU) is limited, making interpretation of images problematic. It is therefore important to characterize normal patterns of RU at specific sites and relate these to age and exercise, to ensure valid interpretation of images in clinical cases with subtle lesions. This study aimed to characterize patterns of uptake of radiopharmaceutical in the distal tarsal region in clinically normal horses, and to invest...
Goodwin M, Klufts M, Workman J, Thambyah A, Vanholsbeeck F.To explore the ability of polarisation-sensitive optical coherence tomography (PS-OCT) to rapidly identify subtle signs of tissue degeneration in the equine joint. Polarisation-sensitive optical coherence tomography (PS-OCT) images were systematically acquired in four locations along the medial and lateral condyles of the third metacarpal bone in five dissected equine specimens. Intensity and retardation PS-OCT images, and anomalies observed therein, were then compared and validated with high resolution images of the tissue sections obtained using Differential Interference contrast (DIC) optic...
Simonato SP, Bernardina GRD, Ferreira LCR, Silvatti AP, Barcelos KMC, da Fonseca BPA.This study aimed to provide a preliminary description of the sagittal and transverse plane kinematics of the thoracolumbar spine of Mangalarga Marchador (MM) horses performing the marcha batida gait, led in-hand. We evaluated the pattern of angular movement and the mean amplitude of six specific angles. An optoelectronic system was used for 3D kinematic analysis (19 cameras, 250 Hz). They were positioned around the horses and an acquisition volume of 16 × 4.8 × 3 meters was used. Eight retroreflective markers were fixed on the spine of the animals over thoracic vertebrae 8 (T8), 12 (T12), 15...
Pessoa CR, Pessoa AF, Maia LA, Medeiros RM, Colegate SM, Barros SS, Soares MP, Borges AS, Riet-Correa F.The effects and susceptibility of donkeys to Crotalaria juncea and Crotalaria retusa poisoning were determined at high and low doses. Seeds of C. juncea containing 0.074% of dehydropyrrolizidine alkaloids (DHPAs) (isohemijunceines 0.05%, trichodesmine 0.016%, and junceine 0.008%) were administered to three donkeys at 0.3, 0.6 and 1 g/kg body weight (g/kg) daily for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was a mild liver megalocytosis in the donkeys ingesting 0.6 and 1 g/kg/day. Two other donkeys that received daily doses of 3 and 5 g seed/...
Laws EG, Freeman DE.Diamine oxidase (DAO), an enzyme of small intestinal origin, is released from mucosal storage sites by IV administration of heparin, to yield the plasma postheparin DAO (PHD) curve. The PHD curve is diminished when mucosal surface area is lost, and baseline (without heparin) plasma DAO activity increases when mucosal storage sites are damaged. Plasma DAO activity was measured after 2 doses of heparin were administered IV in healthy, conscious horses. In anesthetized horses, the PHD curve was studied: during sham small intestinal surgery, and during venous strangulation obstruction (VSO) of the...
Muirhead T, McClure JT, Bourque A, Pack L.A lesion in the cervical region of a 14-month-old Belgian gelding with severe ataxia was suspected. Necropsy revealed symmetric focal cartilage defects compatible with osteochondrosis of the occipital condyles and atlanto-occipital dysplasia. To our knowledge this is the first equine report of symmetrical osteochondrosis of the occipital condyles causing neurologic signs.
Stockert JC, Trigoso CI, Tato A, Ferrer JM.The structure of specific granules from horse eosinophil leukocytes is still largely unknown. In this work, electron microscopical studies of horse eosinophils reveal that the large cytoplasmic granules contain an external membrane, a matrix of less density, and a dense (non crystalline) core. Round vacuolar inclusions of matrix materials were often observed within the cores. Horse eosinophil granules showed a considerable heterogeneity, and three morphological types could be identified according to structural features of the core and matrix.
Leduc L, Leclère M, Lavoie JP.Although horses with asthma share similar clinical signs, the heterogeneity of the disease in terms of severity, triggering factors, inflammatory profile, and pathological features has hindered our ability to define biologically distinct subgroups. The recognition of phenotypes and endotypes could enable the development of precision medicine, including personalized, targeted therapy, to benefit affected horses. While in its infancy in horses, this review outlines the phenotypes of equine asthma and discusses how knowledge gained from targeted therapy in human medicine can be applied to evaluat...
Popot MA, Ho ENM, Stojiljkovic N, Bagilet F, Remy P, Maciejewski P, Loup B, Chan GHM, Hargrave S, Arthur RM, Russo C, White J, Hincks P, Pearce C....Cobalt is an essential mineral micronutrient and is regularly present in equine nutritional and feed supplements. Therefore, cobalt is naturally present at low concentrations in biological samples. The administration of cobalt chloride is considered to be blood doping and is thus prohibited. To control the misuse of cobalt, it was mandatory to establish an international threshold for cobalt in plasma and/or in urine. To achieve this goal, an international collaboration, consisting of an interlaboratory comparison between 5 laboratories for the urine study and 8 laboratories for the plasma stud...
Aleman M.Inflammatory myopathies or myositis encompass diseases characterized by the presence of inflammatory cellular infiltrates, mainly polymorphonuclear cells and/or lymphocytes, in muscle. This is in contrast to most forms of muscle disease characterized by myodegeneration that results in macrophage infiltration. Inflammatory myopathies could have infectious or noninfectious causes. Noninfectious causes consist of primary (genetic, autoimmune) or acquired immune-mediated disease. Focal, multifocal or diffuse, acute or recurrent forms of disease can occur. This article will mainly review immune-med...
Kowalczyk K, Frąckowiak H.Considerable consistency in the arterial pattern of the head has been observed in species of Artiodactyla, but few studies have examined the order Perissodactyla. Here, we describe arteries supplying the intermandibular, mental, masseteric, buccal, labial, and nasal regions in eight perissodactylans, including representing of all families comprising this order. Observations were made on a total of 45 preparations of head arteries, obtained by injection of arteries with acetone-dissolved stained vinyl superchloride or stained latex LBS3060. In the Equidae species alone it was found that the fac...
Loftus L, Asher L, Leach M.Over the last twenty years the definition of good animal welfare has advanced from the 'absence of negative welfare states' to the aim of identifying the presence of positive welfare states; however, research on positive animal welfare is relatively new. Consequently, through expert consultation, this study aimed to synthesise knowledge regarding domesticated equine emotional state, specifically methods to induce and measure positive affective states, which could be of significant benefit to equine welfare across sectors. A Delphi consultation of experts in the field of equine behaviour, welfa...
