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.
Kindig CA, Ramsel C, McDonough P, Poole DC, Erickson HH.Capillary stress failure-induced (exercise-induced) pulmonary haemorrhage (EIPH) during intense running in horses is thought to involve both intravascular (i.e. mean pulmonary arterial pressure [Ppa] > 100 mmHg) and extravascular (e.g. negative inspiratory pressure swings) mechanisms. Objective: That inclined running would reduce breathing frequency (coupled to stride frequency) and increase tidal volume thus increasing lung volume changes and intrapleural pressure swings resulting in more pronounced EIPH. Methods: Six Thoroughbred horses were run to volitional fatigue (incremental step tes...
Bøgh IB, Brink P, Jensen HE, Lehn-Jensen H, Greve T.In the mare, ultrasound-guided transvaginal oocyte recovery and transfer might offer a way to circumvent the demanding procedures of in vitro embryo production. Before clinical application, the possible consequences for subsequent fertility have to be considered. Objective: To examine ovarian function and morphology in mares after repeated follicular punctures. Methods: A total of 14-26 follicular puncture sessions were conducted on each of 4 Norwegian pony mares over a period of 8 years. The ovaries of these mares were recovered by bilateral ovariectomy or at post mortem and subjected to macr...
Dunkel B, McKenzie HC.Sporadic measurement of serum triglycerides in depressed and inappetant clinically ill horses revealed severe hypertriglyceridaemia without visible evidence of lipaemia on several occasions, leading to the inclusion of serum triglyceride concentrations in the routine serum biochemistry evaluation of our hospital. Since then, more cases have been identified and treated for hypertriglyceridaemia, raising questions about the prevalence, predisposing factors and significance of these findings. Objective: 1) Severe hypertriglyceridaemia without visible opacity of the serum occurs more commonly in c...
Baumber J, Sabeur K, Vo A, Ball BA.The objective of this study was to examine the influence of reactive oxygen species (ROS) on equine sperm capacitation. Motile equine spermatozoa were separated on a discontinuous Percoll gradient, resuspended at 10 x 10(6)ml in Tyrode's medium supplemented with BSA (0.5%) and polyvinyl alcohol (0.5%) and incubated at 39 degrees C for 2h with or without the xanthine (X; 0.1mM)-xanthine oxidase (XO; 0.01 U/ml) system or NADPH (0.25 mM). The importance of hydrogen peroxide or superoxide for capacitation was determined by the addition of catalase (CAT; 150 U/ml) or superoxide dismutase (SOD; 150 ...
McKenzie HC.A study was conducted to characterize the aerosols produced by a medical ultrasonic nebulizer using solutions containing antimicrobials appropriate for therapy of equine lower respiratory bacterial infections (gentamicin sulfate and ceftiofur sodium). Test aerosols were generated using an ultrasonic nebulizer and were analyzed using a laser diffraction aerosol particle analyzer. The aerosol was described in terms of the particle size distribution (volume median diameter), span (sample dispersion), and aerosol density (% volume). The particle size distribution and aerosol density of gentamicin ...
Götzen N, Cross AR, Ifju PG, Rapoff AJ.We investigated the microstructural basis of a reduced stress concentration around the primary nutrient foramen of the equine third metacarpus. We quantified the spatial variations of compositional parameters (mineral content, volume fraction, histological architecture, and osteonal trajectories) from microradiographs and polarizing microscopic images of thin sections. These variations in composition and organization in turn cause variations in mechanical properties of cortical bone. We modeled the spatially inhomogeneous anisotropic elastic properties based on the measured compositional param...
Soboll G, Whalley JM, Koen MT, Allen GP, Fraser DG, Macklin MD, Swain WF, Lunn DP.Equine herpesvirus-1 (EHV-1) causes serious disease in horses throughout the world, despite the frequent use of vaccines. CTLs are thought to be critical for protection from primary and reactivating latent EHV-1 infections. However, the antigen-specificity of EHV-1-specific CTLs is unknown. The aim of this study was to identify EHV-1 genes that encode proteins containing CTL epitopes and to determine their MHC I (or ELA-A in the horse) restriction. Equine dendritic cells, transfected with a series of EHV-1 genes, were used to stimulate autologous CTL precursor populations derived from previous...
Harder A, Schmitt-Wrede HP, Krücken J, Marinovski P, Wunderlich F, Willson J, Amliwala K, Holden-Dye L, Walker R.There are three major classes of anthelmintics for veterinary use: the benzimidazoles/prebenzimidazoles, the tetrahydropyrimidines/imidazothiazoles, and the macrocyclic lactones. In nematodes, there are five targets for the existing anthelmintics: the nicotinergic acetylcholine receptor which is the target of tetrahydropyrimidines/imidazothiazoles and indirectly that of the acetylcholineesterase inhibitors; the GABA receptor which is the target of piperazine, the glutamate-gated chloride channel as the target of the macrocyclic lactones, and beta-tubulin as the target of prebenzimidazoles/benz...
Ollivier FJ, Brooks DE, Kallberg ME, Komaromy AM, Lassaline ME, Andrew SE, Gelatt KN, Stevens GR, Blalock TD, van Setten GB, Schultz GS.To examine in vitro effects of various antiproteolytic compounds on activity of matrix metalloproteinase (MMP)-2 and -9 in the tear film of horses with active corneal ulcers. Methods: Samples of tear film obtained from the eyes of 34 horses with active ulcerative keratitis. Methods: Horses were sedated, and tear samples were collected from the lower fornix of 34 ulcerated eyes by use of capillary tubes. The protease inhibitors 0.2% EDTA, 0.1% doxycycline, 10% N-acetylcysteine (NAC), 0.1% solution of a modified dipeptide that contains hydroxamic acid (ie, ilomostat), 0.1% alpha1-proteinase inhi...
Elliott J, Berhane Y, Bailey SR.To determine in vitro vasoactive potency of monoamines formed in the cecum and found in the systemic circulation of horses. Methods: Segments of digital blood vessels obtained from 6 healthy mixed-breed horses and ponies euthanatized at an abattoir and platelets isolated from 4 healthy ponies. Methods: Paired rings of digital artery and vein from the same horse were examined, and isometric tension was recorded. Concentration-response curves for tryptamine (TRP), tyramine (TYR), phenylethylamine (PEA), isoamylamine (IAA), and isobutylamine (IBA) were obtained. Vasoconstrictor mechanisms were in...
Dowdall SM, Proudman CJ, Love S, Klei TR, Matthews JB.Cyathostomins are important equine gastrointestinal parasites. Mass emergence of mucosal stage larvae causes a potentially fatal colitis. Mucosal stages are undetectable non-invasively. An assay that would estimate mucosal larval stage infection would greatly assist in treatment, control and prognosis. Previously, we identified two putative diagnostic antigens (20 and 25 kDa) in somatic larval preparations. Here, we describe their purification and antigen-specific IgG(T) responses to them. Western blots confirmed the purity of the antigens and showed that epitopes in the 20 kDa complex were sp...
Cunningham FM, Vandergrifft E, Bailey SR, Sepulveda MF, Goode NT, Horohov DW.The cytokine, interleukin (IL)-5 stimulates eosinophil differentiation, activation and survival and can prime these cells, increasing the response to other mediators. In view of its many effects on eosinophils, IL-5 has been implicated in the pathogenesis of allergic disease in man. Here we report the cloning of equine IL-5 and expression of the recombinant protein by transfection of Chinese hamster ovary (CHO) cells. The cloned cDNA sequence consisted of 405 nucleotides and encoded a protein of 135 amino acids. There is >85% identity with feline, bovine, ovine, canine, and human IL-5 sequence...
Chen C, Montelaro RC.Synthesis of Gag-Pol polyproteins of retroviruses requires ribosomes to shift translational reading frame once or twice in a -1 direction to read through the stop codon in the gag reading frame. It is generally believed that a slippery sequence and a downstream RNA structure are required for the programmed -1 ribosomal frameshifting. However, the mechanism regulating the Gag-Pol frameshifting remains poorly understood. In this report, we have defined specific mRNA elements required for sufficient ribosomal frameshifting in equine anemia infectious virus (EIAV) by using full-length provirus rep...
Matthee S.Anthelmintic products form the basis of helminth control practices on horse stud farms at present. Regular evaluation of the efficacy of these products is advisable, as it will provide information on the worm egg reappearance period and the resistance status in the worm population. The aim of this study was to evaluate the efficacy of doramectin, pyrantel pamoate, ivermectin and moxidectin on a Thoroughbred stud farm in the Western Cape Province, South Africa. The study also compared the anthelmintic efficacy of two moxidectin formulations administered at their recommended dosages (an injectab...
Carmalt JL, Townsend HG, Allen AL.To evaluate the effect of dental floating on the position of the mandible relative to the maxilla (a measure of rostrocaudal mobility [RCM] of the mandible) during extension and flexion of the head of horses. Methods: Randomized controlled blinded trial. Methods: 59 horses housed in 1 barn. Methods: Horses were formally randomized into a treatment (n = 33) or control (26) group. All horses were sedated, and the distance between rostral portions of the upper and lower incisor arcades were determined with the head fully extended and flexed at the poll (the difference in measurements represented ...
Abraham G, Kottke C, Dhein S, Ungemach FR.Although in the respiratory system there is great therapeutic interest in manipulating and understanding the beta-adrenoceptor-G-protein-adenylate cyclase (AC) signal transduction pathway, little is known on segmental differences among lung, bronchus, and trachea with regard to the receptor concentration and interaction to G-proteins and coupling to AC. In this study, patterns of distribution and absolute quantities of beta-adrenoceptor subtypes beta(1) and beta(2) were determined in membranes of equine lung parenchyma, bronchial and tracheal epithelium with the underlying smooth muscle by sat...
Pirie RS, Dixon PM, McGorum BC.Mould extract inhalation challenges have been used extensively in the investigation of heaves. Such challenges have induced pulmonary neutrophilic inflammation and dysfunction, consistent with, but less severe than the natural disease. However, the method of mould extract production is likely to result in endotoxin contamination. Objective: To investigate whether insufficient dose delivery was responsible for the shortfall in response to inhaled extract compared with natural disease, and whether endotoxin contamination of mould extract contributed to the pulmonary inflammation and dysfunction....
Young LE.Our recent data have confirmed that maximum oxygen delivery in racing Thoroughbreds is positively correlated to left ventricular mass measured by echocardiography. A similar, but weaker relationship also exists between left ventricular mass and Timeform performance rating in commercial racehorses. The relationship of the Thoroughbred heart to racing success and the special problems that selective breeding for aerobic capacity have had in this species are reviewed in this article.
Cook RF, Cook SJ, Berger SL, Leroux C, Ghabrial NN, Gantz M, Bolin PS, Mousel MR, Montelaro RC, Issel CJ.Pathogenicity was reportedly restored to an avirulent molecular clone of equine infectious anemia virus (EIAV) by substitution of 3' sequences from the pathogenic variant strain (EIAV(PV)). However, the incidence of disease in horses/ponies was found to be significantly lower (P = 0.016) with the chimeric clone (EIAV(UK)) than with EIAV(PV). This was attributable to 3' rather than 5' regions of the proviral genome, where EIAV(UK) differs from the consensus EIAV(PV) sequence by having a 68-bp duplication in the 3' LTR and arginine (R(103)) rather than tryptophan (W(103)) at position 103 in the ...
Herrera HD, Duchene AG, Croxatto JO, Burgués N, Amusquibar H.Vascular tumors of the conjunctiva in the horse are rare. We present a unique case of an intravascular papillary endothelial hyperplasia of the conjunctiva. Methods: Horse. Methods: Case report. A 6-year-old-mare presented with a red mass in the conjunctiva of the left eye. After complete ophthalmologic examination the lesion was excised. The tissue was processed for light microscopy and studied histopathologically. Results: Pathologic examination revealed a nonencapsulated vascular lesion composed of confluent vascular spaces filled by multiple papillary structures composed of a central colla...
Taniguchi K, Obitsu T, Ohmura H, Hiraga A, Hata H, Aida H, Akiyama K, Tanaka K.A rigid-type of polyethylene T-cannula was fitted into the anterior ileum of six horses in order to improve the cannulation techniques. A piece of polyethylene net was fastened onto the intestinal wall around the cannula to prevent dislodgment of the cannula by promoting a secure adhesion between the ileum and the abdominal wall. The cannula barrel sheathed with silicone tubing was exteriorized through a stab incision at the lateral ventral wall on the transverse line of the second lumber vertebra, and a flange was screwed onto the barrel. The feeding regime gradually increased concentrate wit...
Haber M, Cao Z, Panjwani N, Bedenice D, Li WW, Provost PJ.The physiologic mechanisms involving growth factors, including PDGF-BB, EGF, and TGF-beta 1, as potent mediators of fibroblasts and epithelial cells in corneal wound healing remain unknown. The goal of this study was to determine culture methods for equine epithelial cells and keratocytes and to investigate how exogenous growth factors influence proliferation of both cell types. Methods: Cell cultures were established from healthy corneas harvested from horses immediately following euthanasia and maintained using standard tissue culture protocols. To determine the effects of PDGF-BB, EGF, TGF-...
Chambers G, Ellsmore VA, O'Brien PM, Reid SW, Love S, Campo MS, Nasir L.The equine sarcoid, one of the most common dermatological lesions in equids, is a benign, locally invasive dermal fibroblastic lesion. Previous studies have suggested an association with two bovine papilloma virus (BPV) types, BPV-1 and BPV-2. In the present study, we examined sarcoids from horses from two geographical areas, Switzerland and the UK, for the major transforming gene of BPV, E5. We detected BPV DNA for the E5 open reading frame and viral E5 RNA transcripts in most sarcoids. Sequence analysis of the E5 open reading frame of sarcoid-associated BPV detected several unique DNA sequen...
Gurfield N, Benirschke K.The placenta from a 300-day-gestational age, female, Arabian equine fetus was examined. Multifocal to coalescing, 0.5- to 4-cm-diameter, white, smooth nodules covered 50% of the placenta. Microscopic evaluation of the nodules revealed undifferentiated germ cells and a haphazard arrangement of immature, mesenchymal stroma, cartilage, squamous cornifying epithelium, scattered ducts and secretory acini lined by cuboidal to columnar epithelium, and mineralized foci. No umbilicus, arrangement about an axial skeleton, or organized polarity of structures was present. The lesion was diagnosed as a pla...
Zerbe H, Castilho LF, Engelke F, Mattos RC, Schuberth HJ, Klug E, Leibold W.Sufficient numbers of functionally competent polymorphonuclear neutrophil granulocytes (PMN) seem to be of major importance during the course of equine endometritis. In this study, we wanted to establish a method for cryopreservation of functionally competent neutrophils for an intended local endometritis therapy in mares. The separation of leucocytes by hypotonic lysis of whole blood from clinically healthy mares was superior to the separation by dextrose sedimentation. After suspension of the cells in the cryoprotective solution [equine plasma with 5% (v/v) dimethyl sulphoxide (DMSO)], the l...
Osterman Lind E, Eysker M, Nilsson O, Uggla A, Höglund J.This study was conducted on a stud farm in Sweden to investigate the species composition of cyathostomins expelled in the faeces of horses after deworming using three different anthelmintic preparations. Twenty-seven horses excreting > or = 200 strongyle eggs per gram faeces (EPG) were divided into three comparable groups and dewormed on day 0 with either of following compounds: 0.2 mg ivermectin per kg body weight (bw), 19 mg pyrantel pamoate per kg bw or 7.5 mg fenbendazole per kg bw. For each of the 3 days following anthelmintic treatment faeces was collected from individual horses and s...
Lyons ET, Tolliver SC.Fenbendazole (FBZ) suspension was administered intraorally at the dose rate of 7.0-10.3 mg/kg once a day for 5 consecutive days to 58 thoroughbred yearlings on two farms in central Kentucky in April, 2002. The average dose rates of drug given to groups of colts and fillies on each farm were 7.8-8.5 mg/kg. Only 3 of the yearlings had negative counts of strongyle eggs per gram of feces (EPGs) after treatment which was at 8.4, 8.7, or 9.4 mg/kg; the pretreatment EPG counts were low (10-30). Reduction of EPG values at the highest dose rates was 0% (at 9.5 mg/kg) and 78% (at 10.3 mg/kg). This study...
Yoshikawa H, Yasu T, Ueki H, Oyamada T, Oishi H, Anzai T, Oikawa M, Yoshikawa T.To evaluate the possibility that Streptococcus equi subsp. zooepidemicus (S.z) the causative bacterial agent of equine shipping fever pneumonia (ESFP), as well as to investigate its pathogenesis, 10 horses (seven Thoroughbreds and three Anglo-Arab species, ranging from 2-4 years in age) were experimentally inoculated, via an endoscope, into bronchus of the lung lobe with a dose of 30 ml of 1-7 x 10(8) CFU/ml of S.z. After inoculation, autopsy and pathological examinations were sequentially conducted 30 min, 1, 2, 3, 4, 17, 20 hr and 2 weeks later. Pneumonia induced by the intrapulmonary inocul...
Nie GJ, Johnson KE, Wenzel JG, Braden TD.Mares (n = 30) were treated in the post-ovulatory period with saline, oxytocin, or cloprostenol (Clo). Dose, administration frequency and treatment day (Day 0, 1 or 2 post-ovulation) were evaluated. Interovulatory interval of control cycles was 22.7 (+/-0.36) days with a range of 20.6 (+/-1.44) to 23.8 (+/-1.39) days among all treatment groups. Mares treated with two micro-doses of cloprostenol on Day 2 post-ovulation had the shortest interovulatory interval. This group also had the lowest mean circulating progesterone concentrations on Days 3-7 and 13, and was the slowest group to reach conce...
Akbari G, Asadiahranjani B, Goodarzi N, Shokrollahi S.Donkeys are a member of the horse family (Equidae) and share a common ancestor. However, in morphological terms, donkeys and horses are regarded as two separate subgenus. Given variations in the branching pattern of the brachiocephalic trunk (BCT) in different species of animals and the use of donkeys in anatomy courses at colleges of veterinary medicine, we conducted this study in order to investigate the branching patterns of BCT and to describe detailed morphological information regarding donkeys. Seventeen mature donkeys were examined following euthanasia by exsanguination from the common ...
Davenport-Goodall CL, Boston RC, Richardson DW.To investigate the effects of insulin-like growth factor-II (IGF-II) on DNA and glycosaminoglycan (GAG) synthesis and the expression of matrix-related genes in equine articular cartilage explants and chondrocytes, respectively, with and without interleukin 1-beta (IL1-beta). Methods: Articular cartilage from 12 adult horses. Methods: Articular cartilage was incubated in standard media with and without equine IL1-beta (10 ng/mL) containing various concentrations of IGF-II for 72 hours. Synthesis of DNA and GAG was determined by incorporation of thymidine labeled with radioactive hydrogen (3H) a...
Vitale V, Berg LC, Larsen BB, Hannesdottir A, Dybdahl Thomsen P, Laursen SH, Verwilghen D, van Galen G.This pilot prospective study reports the feasibility, management and cost of the use of a continuous glucose monitoring (CGM) system in critically ill adult horses and foals. We compared the glucose measurements obtained by the CGM device with blood glucose (BG) concentrations. Neonatal foals (0-2 weeks of age) and adult horses (> 1 year old) admitted in the period of March-May 2016 with clinical and laboratory parameters compatible with systemic inflammatory response syndrome (SIRS) were included. Glucose concentration was monitored every 4 hours on blood samples with a point-of-care (POC) gl...
Rossi G, Richardson A, Jamaludin H, Secombe C.Paraoxonase-1 (PON-1) activity is a new inflammatory and oxidative marker. Technical effects and biological factors could affect the accuracy of PON-1 activity measurement. We investigated the effects of storage at different temperatures, repeated freeze-thaw cycles, interferences from hemolytic, lipemic, and icteric samples, and seasonal effects on PON-1 activity in horses. We evaluated 2 substrates with an automated spectrophotometer. Ten equine serum samples were stored under different conditions. Although storage at room (21°C) or refrigeration (4°C) temperature induced a statistically s...
Current drug metabolismAugust 27, 2022
Volume 23, Issue 10 850-865 doi: 10.2174/1389200223666220825093945
Ishii H, Shibuya M, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Sato F, Kuroda T, Yamada M, Leung GN.Vadadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitor, is a substance which carries a lifetime ban in both horse racing and equestrian competition. A comprehensive metabolic study of vadadustat in horses has not been previously reported. Objective: Metabolism and elimination profiles of vadadustat in equine plasma and urine were studied for the purpose of doping control. Methods: A nasoesophageal administration of vadadustat (3 g/day for 3 days) was conducted on three thoroughbred mares. Potential metabolites were comprehensively detected by differential analysis of ful...
Gastal GDA, Aguiar FLN, Ishak GM, Cavinder CA, Willard ST, Ryan PL, Feugang JM, Gastal EL.Preservation of cellular integrity and its mechanisms after ovarian tissue cryopreservation (OTC) and in vitro culture (IVC) procedures are crucial aspects for the success of preservation and recovery of female fertility. This study aimed to evaluate the effects of two cryopreservation methods (slow-freezing, SF, and vitrification, VIT) on the equine ovarian tissue after 1, 3, and 7 days of IVC by assessing: (i) preantral follicle morphology and distribution of follicle classes; (ii) protein expression of markers of cell proliferation for EGFR and Ki-67; (iii) markers of apoptosis for Bax and...
Watt BC, Edwards RB, Markel MD, McCabe R, Wilson DG.To compare the biomechanical characteristics and mode of failure of 2 parallel-screw techniques for proximal interphalangeal joint arthrodesis in horses. Methods: Randomized block design, blocking for horse (1-5), method of screw fixation (three 4.5-mm vs two 5.5-mm), side (left limb vs right limb), and end (front limb vs hind limb). Constructs were loaded to failure in 3-point bending in a dorsal-to-palmar (plantar) direction. Methods: Twenty limbs (10 limb pairs) from 5 equine cadavers. Methods: A combined aiming device was used to facilitate consistent screw placement. Three parallel 4.5-mm...
Ababneh MM, Troedsson MH.The aim of this study was to determine phospholipase A2 (PLA2) kinetics and activity in the mare's endometrium during the oestrous cycle and early pregnancy. Phospholipase A2 is responsible for the liberation of arachidonic acid from phospholipids, which is the first limiting step in prostaglandins synthesis. Phospholipase A2 activity was measured using an assay based on the liberation of oleic acid from 1-palmitoyl-2-[(14) C] oleoyl phosphatidylcholine. The enzyme was shown to be calcium dependent, to have an optimum pH of 8 and an apparent Michaelis constant of 127 μM. Enzyme activity was l...
Short CR, Horner MW, Blay PK, Moss MS, Edington N, Clarke CR.Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three th...
Maulet BE, Mayhew IG, Jones E, Booth TM.Radiography is a very important aspect of equine stifle imaging. The precise radiographic anatomy of the soft tissue structures of the equine stifle has not been described previously. Objective: To describe the anatomical relationship between sites of attachment of soft tissue structures of the equine stifle and their locations on standard radiographic views. Methods: The sites of bony attachments of the tendons, ligaments and fibrous portion of the joint capsules of equine stifles were determined by gross dissection. These sites of attachment were transposed onto one set of bones deprived of ...
Ben-Shlomo G.Fundus is an anatomic term referring to the portion of an organ opposite from its opening, and the fundus of the eye is the back portion of the posterior segment of the globe, including the optic nerve, retina, and choroid. Clinically, the fundus can be visualized by direct or indirect ophthalmoscopy. Understanding the normal anatomy and appearance of the equine fundus is crucial for differentiating normal variations from abnormalities. This article reviews the normal anatomy and appearance of the equine fundus and discusses basic and advanced examination techniques. It also discusses common f...
Han X, Rossdale PD, Ousey J, Holdstock N, Allen WR, Silver M, Fowden AL, McGladdery AJ, Labrie F, Belanger A.15-hydroxy prostaglandin dehydrogenase (PGDH) is the critical enzyme that determines metabolism of primary prostaglandins. Its expression is determined in part by steroid hormones, particularly progesterone, formed from delta(5) steroids through 3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity. To assess whether the regulation of PGDH might occur in a paracrine, autocrine or intracrine fashion, we used immunohistochemistry (IHC) to determine the localisation of key steroidogenic enzymes in the equine placenta and compared these patterns to the distribution of immunoreactive (IR-) PGDH. ...
Mendoza FJ, Gonzalez-Cara CA, Aguilera-Aguilera R, Toribio RE, Perez-Ecija A.Metabolic disorders are highly prevalent in donkeys. Differences in energy regulatory hormones and glucose dynamic testing, including the intravenous glucose tolerance test (IVGTT) and combined glucose-insulin test (CGIT), have been documented between donkeys and horses. The aims of this study were to characterise the insulin:glucagon (IGR) and glucagon:insulin (GIR) molar ratios, at baseline and in response to the IVGTT and CGIT in healthy donkeys, and to determine their correlation with endocrine (leptin, ghrelin and adiponectin) and morphometric variables. Median values and interquartile ra...
Wagner AL, Urschel KL, Lefta M, Esser KA.To determine the effect of biopsy collection depth on the postprandial activation of mammalian target of rapamycin (mTOR) signaling factors, particularly protein kinase B, ribosomal protein S6 kinase, ribosomal protein S6, and eukaryotic initiation factor 4E binding protein 1 in middle-aged horses. Methods: 6 healthy Thoroughbred mares (mean ± SD age, 13.4 ± 3.4 years). Methods: Horses were fed a high-protein feed at 3 g/kg. Sixty minutes after horses were fed, the percutaneous needle biopsy technique was used to collect biopsy specimens from the gluteus medius muscle at 6, 8, and 10 cm belo...
Skärlina EM, Wilmink JM, Fall N, Gorvy DA.The success of primary healing of equine traumatic wounds is dependent on thorough debridement. A specific hydrosurgical debridement device (Versajet(TM) )(a) is gentle to viable tissues, yet effectively removes macroscopic contaminants and debris. We wished to investigate whether it is effective in reducing bacterial burden and whether it differs from traditional methods. No previous reports compare hydrosurgical debridement and conventional wound debridement with regard to bacterial reduction from in vitro inoculated soft tissue. Objective: To assess the effectiveness of hydrosurgical debrid...
House JA.African horse sickness (AHS), which causes mortality up to 95%, is caused by orbiviruses and is transmitted by Culicoides. The goal of a control and eradication program for AHS is to prevent the spread of the virus via the biological vector. Control measures include slaughter of infected animals, housing of suspected infected animals in insect-proof stalls, and vaccination. Vaccination has played a key role in eradication when AHS occurred outside of Africa. Both modified live vaccines (MLV) and inactivated vaccines have been used to control AHS. An acceptable vaccine should be: safe, efficaci...
Lea RG, Bolton AE.Commercial preparations of equine chorionic gonadotrophin (eCG) and extracts of horse placenta taken at 80 days gestation were incorporated into mixed lymphocyte culture and mitogen stimulation assays of horse peripheral blood mononuclear cells. A dose-related inhibition of lymphocyte proliferation, indicative of immunosuppressive activity, was observed in both systems, both with commercial eCG preparations and tissue extracts. Negligible inhibitory activity was observed with an extract of term placenta. The inhibitory activity of the placental samples was not related to their eCG content as m...
Harkins JD, Mundy GD, Stanley SD, Sams RA, Tobin T.Sarapin is a distillate of the pitcher plant that has long been used in human and veterinary medicine for 'regional analgesia'. The mechanism of the reported analgesic response is unknown; however, the agent is purported to provide more effective analgesia for slow, chronic pain than for sharp, acute pain. Reportedly, Sarapin is also widely used as an analgesic agent in the horse, generally in combination with corticosteroids and other agents. To determine its local anaesthetic efficacy in the horse, we tested Sarapin in a unilateral abaxial sesamoid block model at two dose levels, 2 mL and 10...
De Kock SS, Rodgers JP, Swanepoel BC, Guthrie AJ.This study investigated the biochemical effects of administration of three types of recombinant growth hormone (GH; somatotropin) to the Thoroughbred horse. Equine or bovine or porcine GH was administered at a recommended dosage to 3-5-year old Thoroughbred geldings, for up to 21 days. It was shown that, in addition to equine GH, bovine and porcine GH were active in the horse; however, porcine GH caused injection-site reactions that were so serious that administration had to be terminated. The concentrations of a range of GH-related serum protein markers were determined before, during and afte...
Lord CC, Venter GJ, Mellor PS, Paweska JT, Woolhouse ME.African horse sickness (AHS) and equine encephalosis (EE) viruses are endemic to southern Africa. AHS virus causes severe epidemics when introduced to naive equine populations, resulting in severe restrictions on the movement of equines between AHS-positive and negative countries. Recent zoning of South Africa has created an AHS-free zone to facilitate equine movement, but the transmission dynamics of these viruses are not fully understood. Here, we present further analyses of serosurveys of donkeys in South Africa conducted in 1983-5 and in 1993-5. Age-prevalence data are used to derive estim...
Middlebrooks B, McCue P, Nelson B, May E, Divine C, Barton C, Conley A.Disorders of sexual development (DSD) are associated with atypical chromosomal, gonadal, or phenotypic sex. It is likely that the number of cases of DSD are underestimated in the equine population. Monorchidism in the horse is very rare. This case report describes the clinical assessment of a phenotypic mare with stallion-like behavior which led to the diagnosis of a DSD. A 4-year-old Quarter Horse mare presented in good body condition, with normal external genitalia for a mare, and normal mammary glands with two bilaterally symmetric teats. No uterus, cervix, or gonads were detected on transr...
Maniego J, Pesko B, Habershon-Butcher J, Hincks P, Taylor P, Tozaki T, Ohnuma A, Stewart G, Proudman C, Ryder E.Gene editing and subsequent cloning techniques offer great potential not only in genetic disease correction in domestic animals but also in livestock production by enhancement of desirable traits. The existence of the technology, however, leaves it open to potential misuse in performance-led sports such as horseracing and other equestrian events. Recent advances in equine gene editing, regarding the generation of gene-edited embryos using CRISPR/Cas9 technology and somatic cell nuclear transfer, have highlighted the need to develop tools to detect potential prohibited use of the technology. On...
Laukkanen T, Karma L, Virtala AM, Mykkänen A, Pehkonen J, Rossi H, Tuomola K, Raekallio M.Equine dental diseases are often underdiagnosed and their signs inadequately reported. Many horse owners have difficulties in recognizing pain-related behavioral signs and in associating them with dental pain. Our objective was to determine what type and degree of dental findings may cause behavioral signs associated with dental pain. In this cross-sectional study, dental examination was performed on 183 adult horses and cheek tooth findings were scored. Owners filled in an internet-based questionnaire including 35 questions concerning eating behavior, bit behavior, and general behavior of the...
Höglund N, Koho N, Rossi H, Karttunen J, Mustonen AM, Nieminen P, Rilla K, Oikari S, Mykkänen A.Extracellular vesicles (EVs) are membrane-bound particles that engage in inflammatory reactions by mediating cell-cell interactions. Previously, EVs have been isolated from the bronchoalveolar lavage fluid (BALF) of humans and rodents. The aim of this study was to investigate the number and size distribution of EVs in the BALF of asthmatic horses (EA, = 35) and healthy horses ( = 19). Saline was injected during bronchoscopy to the right lung followed by manual aspiration. The retrieved BALF was centrifuged twice to remove cells and biological debris. The supernatant was concentrated and EVs w...
Muñoz L, Donaire C, Salazar T, Ortiz R, Cruces J, Briones M.The Chilean horse is a breed of closed registry. Stall-walking and weaving are locomotor stereotypies that affect this breed, and genetic predisposition has been suggested for both conditions. The objective of the present study was to estimate heritability of stall-walking and weaving in Chilean horses. Owners of 2,098 horses registered in the Chilean horse Stud Book, which were or had been stabled for at least 1 year, were asked to provide for identification data of the animal and presence or absence of stall-walking and/or weaving. The Chilean Horse Stud Book was accessed online, to collect ...
Potter BM, Scansen BA, Dunbar LK, Reed SM, Toribio RE.There are rare published reports of atrial fibrillation (AF) in foals, all of which are associated with structural heart disease or within the adaptive period of newborns. This report describes a 3-month-old Thoroughbred filly with AF and a structurally normal heart on echocardiography. Medical cardioversion of the foal's AF was attempted with three 20mg/kg doses of quinidine sulfate therapy without success. Timed, transcutaneous, direct current cardioversion was successfully performed using adhesive patches on the midthorax in conjunction with intravenous procainamide at a total dose of 20mg/...
Norris JW, Pombo M, Shirley E, Blevins G, Tablin F.Two congenital bleeding diatheses have been identified in Thoroughbred horses: Glanzmann thrombasthenia (GT) and a second, novel diathesis associated with abnormal platelet function in response to collagen and thrombin stimulation. Objective: Platelet dysfunction in horses with this second thrombasthenia results from a secretory defect. Methods: Two affected and 6 clinically normal horses. Methods: Ex vivo study. Washed platelets were examined for (1) expression of the αIIb-β3 integrin; (2) fibrinogen binding capacity in response to ADP and thrombin; (3) secretion of dense and α-granules; (...
Norrdin RW, Bay BK, Drews MJ, Martin RB, Stover SM.An overload arthrosis occurs consistently in the palmar region of the metacarpal condyle of the equine fetlock (metacarpophalangeal) joint characterized by subchondral bone sclerosis, devitalization and mechanical failure leading to collapse of the overlying articular cartilage. Samples were selected of joints with mild, moderate, and severe subchondral sclerosis, in which cartilage collapse had not yet occurred. An additional group that had severe sclerosis with focal rarefaction suggesting impending collapse was also studied (n=5/group). Parasagittal slices were milled to 2.0 mm thickness an...
Mykkänen AK, Koho NM, Reeben M, McGowan CM, Pösö AR.Polymorphisms in human lactate transporter proteins (monocarboxylate transporters; MCTs), especially the MCT1 isoform, can affect lactate transport activity and cause signs of exercise-induced myopathy. Muscles express MCT1, MCT4 and CD147, an ancillary protein, indispensable for the activity of MCT1 and MCT4. We sequenced the coding sequence (cDNA) of horse MCT4 for the first time and examined polymorphisms in the cDNA of MCT1, MCT4 and CD147 of 16 healthy horses. To study whether signs of myopathy are linked to the polymorphisms, biopsy samples were taken from 26 horses with exercise-induced...
Winder NC, Grünig G, Hermann M, von Fellenberg R.The concentration of soluble fibrinogen derivatives (SFD) and protease and procoagulant activities were determined in cell-free supernatants of equine respiratory secretions obtained from horses with chronic pulmonary disease. The concentration of neutrophils was estimated from direct smears of the secretions. Lung specimens and smears of the secretions were evaluated for the presence of fibrin or fibrinogen by use of immunohistochemical methods. Thirty-five of 80 specimens tested contained SFD. Respiratory secretions from horses with moderate or severe chronic pulmonary disease contained SFD ...
