Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
da Piedade I, Skive B, Christensen H, Bojesen AM.We present the draft genome sequence of Streptococcus equi subsp. zooepidemicus S31A1, a strain isolated from equine infectious endometritis in Denmark. Comparative analyses of this genome were done with four published reference genomes: S. zooepidemicus strains MGCS10565, ATCC 35246, and H70 and S. equi subsp. equi strain 4047.
Seo JP, Tanabe T, Tsuzuki N, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.Osteochondrosis (OC) is a common and clinically important joint disorder in horses. However, repair of the OC region is difficult because of the avascular nature of cartilage. This study aimed to evaluate the efficacy of bilayer gelatin/β-tricalcium phosphate (GT) sponges loaded with mesenchymal stem cells (MSCs), chondrocytes, bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for the repair of osteochondral defects of the talus in horses. Full-thickness osteochondral defects were created on both the lateral trochlear ridges of the talus (n = 6). In the test group, a basic ...
Cox S, Villarino N, Sommardahl C, Kvaternick V, Zarabadipour C, Siger L, Yarbrough J, Amicucci A, Reed K, Breeding D, Doherty T.The objective of this study was to determine if a single loading dose (LD), 3× the label dose of firocoxib oral paste, followed by nine maintenance doses at the current label dose achieves and maintains near steady state concentrations. Six healthy, adult mares were administered 0.3mg/kg of firocoxib on Day 0, and 0.1 mg/kg 24 h later on Day 1, and at 24 h intervals from Day 2 to Day 9, for a total of 10 doses. Blood samples were collected throughout the study. The mean firocoxib maximum plasma concentration and standard deviation was 199±97 ng/mL, 175±44 ng/mL and 183±50 ng/mL after the L...
Wylie CE, Collins SN, Verheyen KL, Newton JR.Laminitis is a highly debilitating disease of the foot known to have a complex and multifactorial aetiology of metabolic, inflammatory, traumatic or vascular origin. The disease has major welfare implications due to unrelenting pain associated with degenerative changes, which often necessitate euthanasia on welfare grounds. Despite this, there have been few high-quality studies investigating risk factors for equine laminitis, and only a limited number of risk factors have been previously investigated. The aim of this study was to conduct a case-control study of risk factors for active episodes...
Pepe M, Angelone M, Gialletti R, Nannarone S, Beccati F.Although arthropathy of the cervical articular process joints (APJs) is common, descriptions of the arthroscopic technique of the cervical APJ have not been reported previously. Objective: To develop an arthroscopic approach to the APJ and to describe the arthroscopic anatomy of the APJ. Methods: Descriptive cadaver study and clinical case report. Methods: The regional anatomy was reviewed and the technique developed on fresh cadaver necks. A series of cadaveric APJ arthroscopies from C2-C3 to C6-C7 were performed to evaluate the procedure, which was then used in 3 clinical cases. A descriptio...
Slater J.Josh Slater looks back at the past 125 years of developments in equine infectious disease, including landmark discoveries in microbiology and genomics, and considers what the future may hold.
Holmquist JG, Schmidt-Gengenbach J, Haultain SA.Grazing management necessarily emphasizes the most spatially extensive vegetation assemblages, but landscapes are mosaics, often with more mesic vegetation types embedded within a matrix of drier vegetation. Our primary objective was to contrast effects of equine grazing on both subalpine vegetation structure and associated arthropods in a drier reed grass (Calamagrostis muiriana) dominated habitat versus a wetter, more productive sedge habitat (Carex utriculata). A second objective was to compare reed grass and sedge as habitats for fauna, irrespective of grazing. All work was done in Sequoia...
Kailaanmäki A, Kinnunen T, Kwok WW, Rytkönen-Nissinen M, Randell J, Virtanen T.The responses of allergen-specific CD4(+) T cells of allergic and healthy individuals are still incompletely understood. Our objective was to investigate the functional and phenotypic properties of CD4(+) T cells of horse-allergic and healthy subjects specific to the immunodominant epitope region of the major horse allergen Equ c 1. Specific T-cell lines (TCLs) and clones were generated from peripheral blood mononuclear cells with Equ c 1(143-160), the peptide containing the immunodominant epitope region of Equ c 1. The frequency, proliferative response, cytokine production and HLA restriction...
Schaffer PA, Wobeser B, Dennis MM, Duncan CG.A retrospective study evaluated the clinical data and histologic features of non-neoplastic dermatologic lesions in skin biopsies from horses, donkeys, and mules submitted over a 10-year period to the Colorado State University Diagnostic Medicine Center and to the University of Saskatchewan Western College of Veterinary Medicine and Prairie Diagnostic Services. A total of 1793 non-neoplastic biopsies were available for analysis. Based on the histologic description and morphologic diagnosis, each submission was classified as inflammatory, or non-neoplastic/non-inflammatory. Results of this stud...
Sheferaw D, Alemu M.The prevalence of equines helminthosis studied from November 2011 to May 2012 in two agroecological zones Damot-Gale district, Wolaita zone, Southern Ethiopia. The objective of the study was to estimate the prevalence, and to see the distribution of internal helminth parasites of equines. A total of 500 faecal samples collected for coprological examination of gastrointestinal helminth ova. From each species of studied animals 200 positive faecal samples were pooled and cultured, and then the larvae recovered and identified. The coprological examination revealed 100 % Strongyle, 16.6 % Fascio...
Votion DM, van Galen G, Sweetman L, Boemer F, de Tullio P, Dopagne C, Lefère L, Mouithys-Mickalad A, Patarin F, Rouxhet S, van Loon G, Serteyn D....It is hypothesised that European atypical myopathy (AM) has a similar basis as seasonal pasture myopathy in North America, which is now known to be caused by ingestion of hypoglycin A contained in seeds from the tree Acer negundo. Serum from horses with seasonal pasture myopathy contained the conjugated toxic metabolite of hypoglycin A, methylenecyclopropyl acetic acid (MCPA). Methods: Retrospective study on archived samples. Objective: 1) To determine whether MCPA-carnitine was present in serum of European horses confirmed to have AM; 2) to determine whether Acer negundo or related Acer speci...
Taylor EA, Beard WL, Douthit T, Pohlman L.Caecal acidosis is a central event in the metabolic cascade that occurs following grain overload. Buffering the caecal acidosis by enterally administered sodium bicarbonate (NaHCO3 ) may be beneficial to affected horses. Objective: To determine the effect and duration of enterally administered NaHCO3 on caecal pH in healthy horses. Methods: Experimental study using horses with caecal cannulas. Methods: Nine horses had been previously fitted with a caecal cannula. Six horses received 1.0 g/kg bwt NaHCO3 and 3 control horses were given 3 l of water via nasogastric tube. Clinical parameters, ...
Slovis NM, Elam J, Estrada M, Leutenegger CM.Diarrhoea caused by infectious agents is common in foals but there is no comprehensive molecular work-up of the relative prevalence of common agents and appearance of coinfections. Objective: To determine the prevalence of 9 infectious agents in gastrointestinal (GI)-diseased and healthy foals with ages ranging from 1 to 20 weeks of age and to what degree coinfections are associated with clinical signs of GI disease. Methods: Retrospective controlled observational study. Methods: The population consisted of 88 Thoroughbred foals aged 2 days to 17 weeks born on 32 different studfarms in Kentuck...
Decloedt A, de Clercq D, van der Vekens N, Verheyen T, van Loon G.Atrial fibrillation cycle length (AFCL) is an indicator of atrial electrical remodelling during atrial fibrillation (AF). Objective: To compare AFCL measured invasively from an intra-atrial electrogram (AFCLEGM ) with AFCL measured noninvasively by atrial colour tissue Doppler imaging (AFCLTDI ). Methods: Prospective descriptive clinical study. Methods: Measurements were performed in 31 episodes of AF or flutter in 29 horses (588 ± 61 kg bwt, 9 ± 3 years old) admitted for transvenous electrical cardioversion. The AFCLEGM was measured from an intracardiac electrogram using a bipolar sensi...
Bowser JE, Elder SH, Pasquali M, Grady JG, Rashmir-Raven AM, Wills R, Swiderski CE.Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive disorder of Quarter Horses characterised by skin fragility. Horses with HERDA have a missense mutation in peptidyl-prolyl cis-trans isomerase B (PPIB), which encodes cyclophilin B and alters folding and post translational modifications of fibrillar collagen. Objective: The study aimed to test the hypothesis that tendons, ligaments and great vessels, which, like skin, are rich in fibrillar collagen, will also have abnormal biomechanical properties in horses with HERDA. Methods: Ex vivo biomechanical study comparing...
Putnam JR, Holmes LM, Green MJ, Freeman SL.Lameness is a common problem in the horse. Despite this, information on the incidence of lameness in horses in the UK is restricted to studies of lameness in performance horses, racehorses or referral hospital populations. Objective: To determine the overall incidence and common causes of lameness in a working horse population and incidence, duration and outcome of conditions observed. Methods: Prospective questionnaire study. Methods: Questionnaires were used to record lameness episodes in 294 horses in an equine military establishment. Information recorded included age, years of service, typ...
Fultz L, Giguère S, Berghaus LJ, Davis JL.Current labelling for the use of ceftiofur crystalline free acid (CCFA) in horses states that 2 i.m. doses must be administered 4 days apart to provide 10 days of therapeutic coverage. A 10 day treatment regimen is not sufficient for the long-term treatment of horses with severe lung consolidation or pleuropneumonia. There are currently no data to guide an appropriate dosing interval when a longer treatment regimen is warranted. Objective: To determine steady-state plasma and pulmonary epithelial lining fluid (PELF) concentrations of desfuroylceftiofur acetamide (DCA) after weekly i.m. adminis...
Jenner F, Närväinen J, de Ruijter-Villani M, Stout TA, van Weeren PR, Brama P.Equine embryogenesis post implantation is not well studied, and only two-dimensional illustrations are available. A thorough appreciation of the complex three-dimensional relationship between tissues and organs and their development is, however, crucial for understanding physiological and pathological mechanisms. Objective: The goals were 2-fold: 1) to establish a freely accessible online atlas as a reference tool for the scientific and pedagogic communities; and 2) to create a framework for integration of data with known spatiotemporal distribution, such as gene expression or cell lineage. Me...
O'Neill HD, Ballegeer EA, De Feijter-Rupp HL, Stick JA, Derksen FJ, Robinson NE.Current diagnosis of recurrent laryngeal neuropathy (RLN) depends upon disease recognition in the clinically affected horse. Biopsy of the intrinsic laryngeal muscles may provide a method to identify the changes in fibre-type composition that occur in RLN before clinical signs become apparent. Objective: To develop an ultrasound-guided biopsy technique of the left cricoarytenoideus lateralis muscle (CALM) and evaluate its efficacy and safety in vivo. Methods: A longitudinal descriptive study. Methods: Six standing horses underwent ultrasound-guided biopsy of the left CALM. Frozen muscle cores ...
Pollina GF, Pepe M, Dean A, Di Marco V, Marton D.Gallium (Ga) is under study for the treatment of osteolytic disorders in equines. Previous studies indicate that oral gallium maltolate (GaM) would provide a higher bioavailability than oral Ga salts. However, oral administration to adult horses of 2 mg/kg of GaM, in the form of a solution mixed with food, did not lead to detectable Ga levels in plasma. Therefore, a study was performed to model the chemical behaviour of GaM in the digestive tract. The equilibrium formation constants for Ga(III) and maltol were calculated by means of UV–visible measurements and validated by 1H-NMR measurement...
Seltenhammer MH, Sundström E, Meisslitzer-Ruppitsch C, Cejka P, Kosiuk J, Neumüller J, Almeder M, Majdic O, Steinberger P, Losert UM, Stöckl J....The Grey horse phenotype, caused by a 4.6 kb duplication in Syntaxin 17, is strongly associated with high incidence of melanoma. In contrast to most human melanomas with an early onset of metastasis, the Grey horse melanomas have an extended period of benign growth, after which 50% or more eventually undergo progression and may metastasize. In efforts to define changes occurring during Grey horse melanoma progression, we established an in vitro model comprised of two cell lines, HoMel-L1 and HoMel-A1, representing a primary and a metastatic stage of the melanoma, respectively. The cell lines ...
Wise LN, Kappmeyer LS, Mealey RH, Knowles DP.Equine piroplasmosis is caused by one of 2 erythrocytic parasites Babesia caballi or Theileria equi. Although the genus of the latter remains controversial, the most recent designation, Theileria, is utilized in this review. Shared pathogenesis includes tick-borne transmission and erythrolysis leading to anemia as the primary clinical outcome. Although both parasites are able to persist indefinitely in their equid hosts, thus far, only B. caballi transmits across tick generations. Pathogenesis further diverges after transmission to equids in that B. caballi immediately infects erythrocytes, wh...
Angenvoort J, Brault AC, Bowen RA, Groschup MH.West Nile virus (WNV) is a flavivirus transmitted between certain species of birds and mosquito vectors. Tangential infections of equids and subsequent equine epizootics have occurred historically. Although the attack rate has been estimated to be below 10%, mortality rates can approach 50% in horses that present clinical disease. Symptoms are most commonly presenting in the form of encephalitis with ataxia as well as limb weakness, recumbency and muscle fasciculation. The most effective strategy for prevention of equine disease is proper vaccination with one of the numerous commercially avail...
Brooks MB, Divers TJ, Watts AE, Ness SL, Frye AH, Stokol T, Fubini SL.To evaluate the platelet activation response before and after treatment with clopidogrel in horses. Methods: 12 healthy adult mares. Methods: In a masked study, horses (6/group) were randomly allocated to alternately receive placebo or clopidogrel via nasogastric tube at a loading dose of 4 mg/kg followed by 2 mg/kg every 24 hours. Blood samples were collected before and 72 hours after initiation of treatment for ADP- and collagen-induced light transmission aggregometry; determination of closure time in collagen-ADP cartridges; modified thrombelastography for comparison of maximal amplitudes g...
Costello S, Heffron B, Taddei L, Benoit M, Hurt L, Simpson L, Bishop J, Folker-Calderon D, Negrusz A.Fluphenazine, a potent antipsychotic used to treat schizophrenia in humans, is used in racehorses as a performance-enhancing drug, and for that reason it has been banned by the Association of Racing Commissioners International. A liquid chromatography-tandem mass spectrometry method for detecting and quantitating fluphenazine in equine serum was developed and validated. The method was then employed to quantitate fluphenazine in serum samples collected from three study horses after intramuscular injection of fluphenazine decanoate. Stability testing showed that fluphenazine is stable in unextra...
Moorman VJ, Reiser RF, Peterson ML, McIlwraith CW, Kawcak CE.To determine kinematic changes to the hoof of horses at a trot after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness values after perineural anesthesia. Methods: 6 clinically normal Quarter Horses. Methods: For each horse, a sole-pressure model was used to induce 3 grades (grades 1, 2, and 3) of lameness in the right forelimb, after which perineural anesthesia was administered to alleviate lameness. Optical kinematics were obtained for both forelimbs with the horse trotting before (baseline) and after induction of each gr...
Chateau H, Degueurce C, Denoix JM.Sharp turns are suspected to increase expression of several distal forelimb lamenesses even at the walk but the biomechanical consequences of such a movement remain unknown. Objective: To quantify the effects of a sharp turn at the walk on the 3-dimensional movements of the distal segments of the forelimb. Methods: Kinematics of the distal segments were measured in 4 healthy horses invasively with an ultrasonic system. Three-dimensional rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained for a turn at the walk were compared to those obtained in a ...
Castro ER, Arbiza J.Infection with equid alphaherpesvirus 1 (EHV-1) causes respiratory disease, abortion and neurological disorders in horses. Molecular epidemiology studies have demonstrated that a single nucleotide polymorphism (A2254/G2254) in the genome region of open reading frame 30 which results in an amino acid variation (N752/D752) of the EHV-1 DNA polymerase, is significantly associated with the neuropathogenic potential of naturally occurring strains. In recent years, an increase in the number of cases of equine neurological disease caused by neuropathogenic variants of EHV-1 has been observed in numer...
Lear TL.Telomeres are a class of repetitive DNA sequences that are located at chromosome termini and that act to stabilize the chromosome ends. The rapid karyotypic evolution of the genus Equus has given rise to ten taxa, all with different diploid chromosome numbers. Using fluorescence in situ hybridization (FISH) we localized the mammalian telomere sequence, (TTAGGG)(n), to the chromosomes of nine equid taxa. TTAGGG signal was located at chromosome termini in all species, however additional signal was seen at interstitial sites on some chromosomes in the Burchell's zebra, Equus quagga burchelli, the...
Frellstedt L, McKenzie HC, Barrett JG, Furr MO.Endotoxemia is responsible for severe illness in horses. Individuals can become clinically unresponsive to the endotoxin molecule after an initial exposure; a phenomenon referred to as 'endotoxin tolerance' (ET). ET has been observed clinically in horses in vivo; however, cytokine expression associated with ET has not been investigated. The purpose of this study was to develop and validate a method for inducing ET in equine peripheral blood mononuclear cells (PBMC) in vitro, and to describe selected cytokine responses which are associated with ET. ET was induced by culturing cells with three c...
Lentz LR, Valberg SJ, Herold LV, Onan GW, Mickelson JR, Gallant EM.To determine whether alterations in myoplasmic calcium regulation can be identified in muscle cell cultures (myotubes) and intact muscle fiber bundles derived from Thoroughbreds affected with recurrent exertional rhabdomyolysis (RER). Methods: 6 related Thoroughbreds with RER and 8 clinically normal (control) Thoroughbred or crossbred horses. Methods: Myotube cell cultures were grown from satellite cells obtained from muscle biopsy specimens of RER-affected and control horses. Fura-2 fluorescence was used to measure resting myoplasmic calcium concentration as well as caffeine- and 4-chloro-m-c...
Issouf M, Vargas A, Boivin R, Lavoie JP.Airway wall remodeling, including hyperplasia and hypertrophy of smooth muscle (ASM) cells leading to an increased smooth muscle mass, is considered central to asthma. However, molecular pathways responsible for ASM remodeling remain poorly understood. MicroRNAs (miRNAs) have emerged as key regulators of inflammatory and repair processes affecting the lungs and can downregulate protein expression by inhibiting target mRNA translation. We therefore hypothesized that miRNAs are involved in ASM remodeling in asthma by modulating ASM proliferation. We have analyzed the expression of miRNAs in bron...
Ho EN, Kwok WH, Lau MY, Wong AS, Wan TS, Lam KK, Schiff PJ, Stewart BD.A veterinary preparation known as TB-500 and containing a synthetic version of the naturally occurring peptide LKKTETQ has emerged. The peptide segment (17)LKKTETQ(23) is the active site within the protein thymosin β(4) responsible for actin binding, cell migration and wound healing. The key ingredient of TB-500 is the peptide LKKTETQ with artificial acetylation of the N-terminus. TB-500 is claimed to promote endothelial cell differentiation, angiogenesis in dermal tissues, keratinocyte migration, collagen deposition and decrease inflammation. In order to control the misuse of TB-500 in equin...
Schneider N, Lejeune JP, Deby C, Deby-Dupont GP, Serteyn D.Ischaemia and reperfusion are suspected to alter chondrocyte metabolism. Here, we studied the effects of three oxygen (O2) tensions on the viability of equine articular chondrocytes isolated from the cartilage of the distal interphalangeal joint of horses. Chondrocytes were cultured in alginate beads under 1%, 5% or 21% gas phase O2 concentration for 14 days, cellular growth kinetics were measured (n=6), and the cells were observed by light microscopy after staining for necrotic and apoptotic cell detection. For information about the metabolic status, the intracellular adenosine triphosphate (...
Schwinghamer R, Massolo A, Knight C, Klein C.This study evaluated equine endometrial explants following 12, 24, and 48 hr in culture. Measurement of an indicator of cell death in explant supernatant, light microscopy, and gene expression of biomarkers of endometrial function and cellular stress were used to compare the effect of six different media on explant viability and morphology. Viability of explants was assessed indirectly through measuring LDH activity in the culture supernatant. Regardless of culture medium composition, a significant increase in LDH activity was observed within 12 hr of culture, indicating occurrence of cell dam...
The Journal of heredityJanuary 27, 2008
Volume 99, Issue 2 125-129 doi: 10.1093/jhered/esm106
Wittwer C, Dierks C, Hamann H, Distl O.A previously accomplished whole-genome scan for osteochondrosis (OC) and OC dissecans (OCD) in South German Coldblood horses using 250 microsatellite markers identified putative quantitative trait loci (QTL). A chromosome-wide significant QTL for fetlock OCD was found on Equus caballus chromosome (ECA) 4q at a relative position of 70.0-73.3 cM. The aim of this study was to analyze associations of single nucleotide polymorphisms (SNPs) in candidate genes for OC in this region. The association analysis included 32 affected and 64 unaffected horses. Three SNPs located in intron 8, intron 9, and 3...
Curik I, Fraser D, Eder C, Achmann R, Swinburne J, Crameri R, Brem G, Sölkner J, Marti E.To investigate whether the equine major histocompatibility complex (MHC) gene region influences the production of mould-specific immunoglobulin E antibodies (IgE), alleles of the equine leukocyte antigen (ELA-A) locus and three microsatellite markers (UM-011, HTG-05 and HMS-42) located on the same chromosome as the equine MHC were determined in 448 Lipizzan horses. Statistical analyses based on composite models, showed significant associations of the ELA-A and UM-011 loci with IgE titres against the recombinant Aspergillus fumigatus 7 antigen (rAsp f 7). UM-011 was also significantly associate...
Sánchez-Casanova RE, Masri-Daba M, Alonso-Díaz MÁ, Méndez-Bernal A, Hernández-Gil M, Fernando-Martínez JA.A wide spectrum of welfare issues is encountered on working equids. The objectives of this study were: (i) to determine the prevalence of cutaneous lesions in working equids in tropical regions of the North-Central of Veracruz State, Mexico, (ii) to identify the most prevalent cutaneous pathological conditions in this population of working equids, and (iii) to identify risk factors associated to the presence of work-related skin wounds. A number of 467 working equids presented for treatment at Donkey Sanctuary Mobile Clinic Program - National Autonomous University of Mexico from seven differen...
Juffo GD, Bassuino DM, Gomes DC, Wurster F, Pissetti C, Pavarini SP, Driemeier D.The Salmonella sp. genus is identified in several species, and the zoonosis it causes is one of the most important types worldwide. The specifics of salmonellosis vary according to the function of the serovar involved, the species affected, age and predisposing factors. However, few cases of equine salmonellosis have been reported. This study presents ten confirmed salmonellosis cases in equines in southern Brazil. Six were adult animals with stress factors preceding the disease, while four were foals, three of which presented with hyperacute manifestations. The main clinical signs were diarrh...
Kuzmina TA.Analysis of the influence of horse-keeping conditions by contamination of the environment (pastures, paddocks, and stalls) by the strongylid infective larvae (L(3)) was carried out at various types of horse farms, hippodromes, and riding clubs in Ukraine. A total of 1,237 horses from three types of horse-keeping conditions were examined. Epidemiological studies of stall and grazing area (pasture and paddocks) contamination by L(3) were performed at hippodrome (stalled horse-keeping) and horse farms with stall/paddock-keeping and stall/pasture-keeping conditions. Grass and stall litter samples ...
Cruz F, Fores P, Mughini-Gras L, Ireland J, Moreno MA, Newton JR.Equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) have a worldwide distribution and cause respiratory disease, abortion, neonatal death and myeloencephalopathy in susceptible horses. Given the scarcity of serological EHV-1/EHV-4 data in Spain, the objective of this cross-sectional study was to estimate the seroprevalence of EHV-1/EHV-4 and to identify potential horse-level and stud farm-level factors associated with EHV-1/EHV-4 in the breeding Spanish Purebred (SP) horse population in central Spain. Serum samples from 334 SP unvaccinated horses, collected between September 2011 and November...
Batellier F, Duchamp G, Vidament M, Arnaud G, Palmer E, Magistrini M.Milk-based semen diluents are known to be practical and effective in protecting equine spermatozoa during storage before artificial insemination. Milk is a biological fluid with a complex composition and contains components which are beneficial or harmful to spermatozoa. The aim of this study was to test the fertility of stallion semen after long-term storage using different milk diluents (INRA 82 or Kenney's diluent) vs one diluent chemically defined (INRA 96), which is composed of efficient milk components and optimized for sperm survival and storage temperature. The milk fraction used was t...
Underwood C, van Eps AW, Ross MW, Laverman P, van Bloois L, Storm G, Schaer TP.Liposomes are phospholipid nanoparticles that extravasate at sites of increased vascular permeability. They have potential in equine medicine for targeted drug delivery and diagnostic imaging of infectious, inflammatory and neoplastic lesions. Objective: This study evaluates the safety and biodistribution of i.v. polyethyleneglycol(PEG) liposomes in normal horses. Methods: PEG-liposomes were prepared by the film hydration method and labelled using (99m) Tc-hexamethyl-propylene-amine-oxime. A single dose of 0.24 µmol/kg bwt (99m) Tc-PEG-liposomes and 2.4 µmol/kg bwt unlabelled PEG-liposomes...
Hoffmann ALC, Hauck SM, Deeg CA, Degroote RL.In the pathophysiology of autoimmune-mediated uveitis, granulocytes have emerged as possible disease mediators and were shown to be pre-activated in equine recurrent uveitis (ERU), a spontaneous disease model. We therefore used granulocytes from ERU horses to identify early molecular mechanisms involved in this dysregulated innate immune response. Primary granulocytes from healthy and ERU horses were stimulated with IL8, and cellular response was analyzed with differential proteomics, which revealed significant differences in protein abundance of 170 proteins in ERU. Subsequent ingenuity pathw...
Castaneda C, Juras R, Kjöllerström J, Hernandez Aviles C, Teague SR, Love CC, Cothran EG, Varner DD, Raudsepp T.This is a follow-up study to validate the previously detected association of the FKBP6 gene with stallion subfertility. Using a select cohort of 150 Thoroughbred stallions with detailed breeding records, we confirm significant association (P < 0.0001) between low per-cycle pregnancy rates (≤50%) and a combined A/A-A/A genotype of SNPs chr13:11 353 372G>A and chr13:11 353 436A>C in FKBP6 exon 5. We also show that stallion subfertility and the combined genotype A/A-A/A are not associated with the level of genetic diversity based on 12 autosomal microsatellite markers, or with pedig...
Turell MJ, O'Guinn ML, Parker MD.Specific mutations associated with attenuation of Venezuelan equine encephalitis (VEE) virus in rodent models were identified during efforts to develop an improved VEE vaccine. Analogous mutations were produced in full-length cDNA clones of the Cba 87 strain of western equine encephalitis (WEE) virus by site-directed mutagenesis in an attempt to develop an improved WEE vaccine. Isogenic viral strains with these mutations were recovered after transfection of baby hamster kidney cells with infectious RNA. We evaluated two of these strains (WE2102 and WE2130) for their ability to replicate in and...
Schemann K, Firestone SM, Taylor MR, Toribio JA, Ward MP, Dhand NK.In August 2007, Australia experienced its first-ever outbreak of equine influenza, a highly infectious respiratory disease of horses. Although the outbreak spread over a large geographic area, it was eradicated within 5 months following a substantial disease control effort led by federal and state animal health authorities. Despite its timely control, this large-scale outbreak caused severe impacts on horse owners and industry participants. This study aimed to describe the perceptions of horse owners and managers, impacted by outbreak control measures, regarding the state government's animal h...
Spencer JA, Ellison SE, Guarino AJ, Blagburn BL.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome seen in horses from the Americas and is mainly caused by Sarcocystis neurona. Cell-mediated immune responses to mitogens have been shown to be reduced in horses with EPM, although it is not known whether the parasite causes this immunosuppression or if the immunosuppression is required for disease manifestation. Recently, a 29-kDa surface antigen from S. neurona merozoites was identified as being highly immunodominant on Western blot. This antigen has been sequenced and cloned, and the expressed protein has been named SnSAG1. Is...
Brazil TJ, Rossi AG, Haslett C, McGorum B, Dixon PM, Chilvers ER.The synthetic formylpeptide fMLP is widely used as a model chemoattractant and secretagogue for mammalian neutrophils. Despite possessing fMLP receptors, equine neutrophils do not produce superoxide anions in response to fMLP and there is no inflammatory reaction in the horse when fMLP is injected intradermally. The functional capability of these receptors was investigated after pretreatment with recognized priming agents. Purified neutrophils were pretreated with lipopolysaccharide (LPS), platelet-activating factor (PAF), or tumor necrosis factor alpha (TNF-alpha) and superoxide anion generat...
Pretorius A, Van Kleef M, Van Wyngaardt W, Heath J.African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV naïve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4⁺ cells. In additio...
Palomero AM, Hernández JA, Cazapal-Monteiro CF, Balán FA, Silva MI, Paz-Silva A, Sánchez-Andrade R, Vázquez MSA.The integrated control of strongyles was assayed for a period of three years in wild equids (zebras, European donkeys, and African wild asses) captive in a zoo and infected by strongyles. During three years control of parasites consisted of deworming with ivermectin + praziquantel; equids also received every two days commercial nutritional pellets containing a blend of 10 - 10 spores of the fungi + per kg meal. Coprological analyses were done monthly to establish the counts of eggs of strongyles per gram of feces (EPG). The reductions in the fecal egg counts (FECR) and in the positive horses...
Dell A, Curry M, Yarnell K, Starbuck G, Wilson PB.The Cleveland Bay horse is one of the oldest equines in the United Kingdom, with pedigree data going back almost 300 years. The studbook is essentially closed and because of this, there are concerns about loss of genetic variation across generations. The breed is one of five equine breeds listed as "critical" (<300 registered adult breeding females) by the UK Rare Breeds Survival Trust in their annual Watchlist. Due to their critically endangered status, the current breadth of their genetic diversity is of concern, and assessment of this can lead to improved breed management strategies. Herein...
Page PC, Labuschagne K, Venter GJ, Schoeman JP, Guthrie AJ.The efficacy of untreated and alphacypermethrin-treated high density polyethylene (HDPE) mesh against Culicoides biting midges (Diptera: Ceratopogonidae) was determined using Onderstepoort downdraught black light traps and a contact bioassay. Three traps were operated overnight in four replicates of a 3×3 randomised Latin square design near horses under South African field conditions. Both the untreated and alphacypermethrin-treated HDPE mesh significantly (P<0.05) reduced the numbers of Culicoides midges, predominantly Culicoides (Avaritia) imicola Kieffer, collected in the light traps by...
Mohamed FH, Abu Samra MT, Ibrahim KE, Idris SO.Cutaneous habronemiasis in 15 horses and 5 donkeys is described. The lesions were distributed in many parts of the body involving the medial canthus, shoulder and pectoral regions, knee and fetlock joints, abdominal wall and prepuce. Some animals had more than one lesion. The lesions were ulcerative and filled with soft light red granulation tissue. When curretted, the deeper layers revealed a dense fibrous tissue with calcified foci. Close examination of the lesions showed that the superficial layer of this dense fibrous tissue contained small caseated and necrotic foci. The same features pre...
Rötting AK, Freeman DE, Constable PD, Eurell JA, Wallig MA.To establish reference values for the range of the number of eosinophils found in equine gastrointestinal mucosa and to describe the distribution of this cell within the equine gastrointestinal mucosa. Methods: Gastrointestinal mucosal specimens from 14 adult horses euthanatized for reasons other than gastrointestinal disease. Methods: Gastrointestinal mucosal specimens were collected and grouped according to their anatomic regions. For histologic examination slides were stained with Luna's eosinophil stain to determine eosinophil accumulation and distribution. The mucosa was divided into 5 se...
Leclere M, Bédard C, Cortes-Dubly ML, Lavoie JP.As inflammation and coagulation are intertwined processes, the efficiency of blood coagulation of heaves-affected horses and controls were compared in an observational case-control study, using thrombelastography. In experiment 1 (Exacerbation, six heaves, five controls), horses were housed indoors and fed hay. Thrombelastography, functional fibrinogen, platelet count, hematology, and antithrombin were measured. In experiment 2 (Remission, eight heaves, 11 controls), horses were housed in a low-dust environment for at least a month when thrombelastography was performed. Heaves-affected horses ...
