The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Stokes SM, Belknap JK, Engiles JB, Stefanovski D, Bertin FR, Medina-Torres CE, Horn R, van Eps AW.Continuous digital hypothermia can prevent the development and progression of laminitis associated with sepsis but its effects on laminitis due to hyperinsulinaemia are unknown. Objective: To determine the effects of continuous digital hypothermia on laminitis development in the euglycaemic hyperinsulinaemic clamp model. Methods: Randomised, controlled (within subject), blinded, experiment. Methods: Eight clinically normal Standardbred horses underwent laminitis induction using the euglycaemic hyperinsulinaemic clamp model (EHC). At initiation of the EHC, one forelimb was continuously cooled (...
Contreras-Aguilar MD, Martínez-Subiela S, Cerón JJ, Martín-Cuervo M, Tecles F, Escribano D.Salivary biomarkers could be useful to objectively evaluate critical illness and prognosis for survival in horses with acute abdominal disease. Objective: To compare salivary alpha-amylase (sAA) activity and concentration in healthy horses and horses with acute abdominal disease, and evaluate the association between sAA activity and concentration with disease severity and outcome. Methods: A prospective cohort. Methods: sAA activity, measured using a colorimetric commercial kit, and concentration, measured using a Time-resolved immunofluorometric assay, in 25 healthy horses and in 33 horses wi...
Warren A.A 5-year-old Hanoverian horse was presented for a palpable and visible mass over the frontal and maxillary sinuses. Following endoscopy and radiography surgical excision was attempted. The horse was euthanized during surgery and samples of the mass were identified as malignant anaplastic sarcoma, a seldom reported sinonasal tumor in equids. Sarcome anaplasique naso-sinusien équin infecté par Escherichia coli multirésistant aux antibiotiques. Un cheval Hanovrien âgé de 5 ans a été présenté pour une masse palpable et visible sur les sinus frontal et maxillaire. Après une endoscopie et ...
Kolb DS, Klein C.Congenital hydrocephalus has been reported for a number of horse breeds, and for Friesian horses this condition has been associated with a nonsense mutation of B3GALNT2. We report the first case of congenital hydrocephalus associated with the said mutation in a Belgian draft horse. Genetic testing and consideration of the testing results in breeding programs are warranted. Hydrocéphalie congénitale chez un cheval de trait Belge associée à une mutation non-sens de B3GALNT2. L’hydrocéphalie congénitale a été signalée pour plusieurs races de chevaux et, pour les chevaux Frisons, cette ...
Berryhill EH, Magdesian KG, Tadros EM, Edman JE.Maintaining serum glucose concentrations is critical in neonatal foals and is often dysregulated in illness; however, few studies have assessed the effects of age, or variation of glucose and insulin, in neonates and their postpartum dams. This study aimed to serially evaluate serum glucose and insulin concentrations and glucose/insulin (G/I) ratios in seven healthy foals and their dams immediately postpartum and at 1-2 and 10-12days of age. The hypotheses were that: (1) there would be wide temporal variation in hourly glucose and insulin measurements among foals; and (2) measured parameters i...
Knickelbein KE, Luethy D, Thomasy SM, Reilly C, Strom AR, Lassaline ME.(a) To evaluate the epidemiology of equine eosinophilic keratoconjunctivitis (EK) in the western United States, (b) to ascertain the efficacy of keratectomy and diamond burr debridement vs medical management alone, (c) to determine the efficacy of various medical therapies, and (d) to further characterize the histopathologic findings of the disease in horses. Methods: Twenty-nine horses (47 eyes) diagnosed with EK from 1993 to 2017. Methods: Retrospective medical record review; owner questionnaire. Results: Average age of presentation was 11 ± 4 years. Warmbloods were significantly overrep...
Bino E, Lauková A, Ščerbová J, Kubašová I, Kandričáková A, Strompfová V, Miltko R, Belzecki G.The intestinal microbiota has enormous impact on the health and performance of horses. Staphylococci belong in the phylum Firmicutes, and their occurrence, especially of methicillin-resistant strains and species, has been reported in horses previously. Moreover, biofilm formation is one of the virulence factors; it has been not completely studied in fecal coagulase-negative staphylococci (CoNS) from horses. Therefore, this study was focused on biofilm formation by various species of fecal CoNS from horses because it has been never reported before. In addition, their antibiotic profile was test...
González-Medina S, Montesso F, Chang YM, Hyde C, Piercy RJ.Several pasture management strategies have been proposed to avoid hypoglycin A (HGA) intoxication in horses, but their efficacy has never been investigated. Objective: To evaluate the effect of mowing and herbicidal spraying on HGA content of sycamore seedlings and the presence of HGA in seeds and seedlings processed within haylage and silage. Methods: Experimental study. Methods: Groups of seedlings were mowed (n = 6), sprayed with a dimethylamine-based (n = 2) or a picolinic acid-based herbicide (n = 1). Seedlings were collected before intervention, and at 48 h, 1 and 2 weeks after. ...
Pluháček J, Tučková V, King SRB, Šárová R.Overmarking occurs when one individual places its scent mark directly on top of the scent mark of another individual. Although it is almost ubiquitous among terrestrial mammals, we know little about the function of overmarking. In addition, almost all studies on mammalian overmarking behaviour dealt with adult individuals. Reports on this behaviour in juveniles are extremely rare, yet may elucidate the function of this behaviour. We tested four mutually non-exclusive hypotheses which might explain this behaviour in juveniles: (1) conceal the individual's scent identity, (2) announcement of ass...
Sperl C, Gerber V, Drießlein D, Klima A, Becher AM.Respiratory signs or more specifically severe equine asthma (SEA) is in some studies reported to be associated with decreased strongyle egg shedding. This association can be reproduced in a larger population of unrelated horses. The owners of 209 horses, on seven farms in Bavaria, were interviewed using, an in prior studies validated questionnaire. Horses were categorized into classes of the horse owner assessed respiratory signs index (HOARSI 1-4, unaffected to severely affected). In total, 1,035 fecal samples were analyzed between March 2011 and September 2014 using a modified McMaster proce...
Slivinska K, Karbowiak G, Gawor J, Wróblewski Z, Jaworski Z, Jastrzębska E, Demeshkant V.The influence of internal and external parasites on the health of Polish konik horses housed in different types of management strategies in Poland is discussed. This study includes consolidated data of different authors from the past 50 years, supplemented by results of more recent research. A total of 38 species of helminths (i.e., 37 Nematoda and one Cestoda) and five Diptera species were recorded from the horses. Protozoan parasites, Cryptosporidium spp. and Theileria equi, and the Rickettsiales, Anaplasma phagocytophilum, were observed for the first time in Poland.
Sheldon SA, Aleman M, Costa LRR, Santoyo AC, Howey Q, Madigan JE.Trigeminal-mediated headshaking results from low-threshold firing of the trigeminal nerve resulting in apparent facial pain. Magnesium may have neuroprotective effects on nerve firing that potentially dampen signs of neuropathic pain. This hypothesis has not been investigated in horses with trigeminal-mediated headshaking. Objective: To investigate head-shaking behavior in affected horses after IV magnesium sulfate infusion. Methods: Six geldings with trigeminal-mediated headshaking. Methods: Prospective randomized crossover study. Horses were controlled for diet and infused IV with 5% dextros...
Stein L, Sledge D, Smedley R, Kiupel M, Thaiwong T.A 15-y-old Miniature horse mare had a 6-mo history of an ulcerated mass on the right lower eyelid. An incisional biopsy and a subsequent excisional biopsy were submitted to the Michigan State University Veterinary Diagnostic Laboratory for microscopic evaluation. Histologically, the incisional biopsy was composed of sheets of large neoplastic vacuolated polygonal cells. A few regions contained poorly differentiated neoplastic round-to-basaloid cells that rimmed the sheets of highly vacuolated polygonal cells. Both vacuolated and basaloid cells exhibited strong perimembranous and cytoplasmic im...
Miglio A, Morelli C, Gialletti R, Lauteri E, Sforna M, Marenzoni ML, Antognoni MT.The clinical, histological, and immunophenotypic findings are presented for 4 horses affected by different types of lymphoma. Diagnoses of a monomorphic epitheliotropic intestinal T-cell lymphoma, a diffuse splenic large B-cell lymphoma, a peripheral T-cell lymphoma, and a T-cell rich large B-cell lymphoma of the third eyelid were made. Constatations cliniques et immunophénotypiques pour quatre formes de lymphomes équins. Les constatations cliniques, histologiques et immunophénotypiques sont présentées pour quatre chevaux affectés par différents types de lymphome. Des diagnostics d’un...
Coleman MC, Walzem RL, Kieffer AJ, Minamoto T, Suchodolski J, Cohen ND.Lipoproteins are water-miscible macromolecules enabling the transport of lipids in blood. In humans, altered proportions of lipoproteins are used to detect and classify metabolic diseases. Obesity and obesity-related comorbidities are common in horses. The pathophysiology of obesity is poorly understood and likely multifactorial. Development of new diagnostic tests to identify horses at risk of developing obesity to implement preventative measures is critical; however, a necessary first step to accomplish this goal is to improve our understanding of the pathophysiology of disease. Thus, the ob...
Pollard D, Wylie CE, Newton JR, Verheyen KLP.Previous robust epidemiological studies of equine laminitis have utilised only veterinary-diagnosed episodes of disease, potentially underestimating true disease frequency. Objective: To estimate the incidence of, and describe clinical signs associated with, owner-reported active laminitis in horses/ponies, using both veterinary-diagnosed and nonveterinary-diagnosed episodes. Methods: Prospective cohort. Methods: Data were collected from horse/pony owners in Great Britain between August 2014 and December 2016 using a web-based application. The incidence of owner-reported laminitis was estimate...
de Lagarde M, Larrieu C, Praud K, Schouler C, Doublet B, Sallé G, Fairbrother JM, Arsenault J.Although antimicrobial resistance is increasingly common in equine medicine, molecular and epidemiological data remains scarce. Objective: We estimated the prevalence of, and risk factors for, shedding of multidrug resistant (MDR), extended spectrum β-lactamase (ESBL)-producing, and AmpC β-lactamase-producing, or some combination of these in Escherichia coli in horses in France. We characterized ESBL/AmpC isolates for antimicrobial susceptibility and the presence of virulence and ESBL/AmpC-associated resistance genes. Methods: Fecal samples from healthy adult horses at 41 premises were colle...
Francesca Martelli, Sue Kidd and Joanna Lawes of the APHA discuss surveillance findings relating to Salmonella isolates from horses, and also the antimicrobial resistance patterns being seen.
Roberts V.Trigeminal-mediated headshaking is a little-understood neuropathic facial pain condition of the horse. The condition may affect around 1% of the equine population to a degree of severity sufficient to require veterinary attention. As a pain condition, this represents a significant welfare issue. Horses are usually more severely affected at exercise which can leave them unable to perform, or even dangerous to ride and handle. With little known about the condition and variable response to treatments, severely affected horses are often euthanized. This review article considers the literature on t...
Gianino GM, Valberg SJ, Perumbakkam S, Henry ML, Gardner K, Penedo C, Finno CJ.Immune-mediated myositis (IMM) in American Quarter Horses (QHs) causes acute muscle atrophy and lymphocytic infiltration of myofibers. Recently, an E321G mutation in a highly conserved region of the myosin heavy chain 1 (MYH1) gene was associated with susceptibility to IMM and nonexertional rhabdomyolysis. Objective: To estimate prevalence of the E321G MYH1 variant in the QH breed and performance subgroups. Methods: Three-hundred seven elite performance QHs and 146 random registered QH controls. Methods: Prospective genetic survey. Elite QHs from barrel racing, cutting, halter, racing, reining...
Kecerova Z, Cizek A, Nyc O, Krutova M.Clostridium difficile has been recovered from the faeces of several animal species as well as horses. Between April 2015 and October 2016, 213 samples of faeces from non-hospitalized (n = 138) and hospitalized horses (n = 75) were investigated and eighteen C. difficile isolates were cultured using an enrichment method. Sixteen C. difficile positive samples were identified from hospitalised horses (p < 0.01). Molecular typing revealed seven ribotypes and sequence types (RT033/ST11 n = 8, 44.4%; RT081/ST9 n = 4, 22.2%; RT009/ST3 n = 2, 11.1%; RT003/ST12 n = 1, 5.6%;...
Seo MG, Ouh IO, Choi E, Kwon OD, Kwak D.The identification and characterization of pathogenic and zoonotic tick-borne diseases like granulocytic anaplasmosis are essential for developing effective control programs. The differential diagnosis of pathogenic Anaplasma phagocytophilum and non-pathogenic A. phagocytophilum-like Anaplasma spp. is important for implementing effective treatment from control programs. The objective of the present study was to investigate the prevalence of Anaplasma spp. in horses in Korea by nucleotide sequencing and restriction enzyme fragment length polymorphism assay. Of the 627 horses included in the stu...
Gehlen H, Shety T, El-Zahar H, Hofheinz I.Cardiac biomarkers are important tools for monitoring disease progress and can monitor progression of therapy. Endothelin-1 (ET-1) has been studied for its use as a cardiac biomarker in human and small animal medicine while in horses with cardiac disease it has not been evaluated yet. The objective of the present study was to determine the concentration of plasma ET-1 in healthy horses and compare it with ET-1 concentration in horses with cardiac disease during rest and after exercise. Fifty four horses admitted to the Equine Clinic of Free University of Berlin were used in the present study, ...
Adair S, Baus M, Bell R, Boero M, Bussy C, Cardenas F, Casey T, Castro J, Davis W, Erskine M, Farr R, Fischer A, Forbes B, Ford T, Genovese R....No abstract available
Simões J, Sales Luís J, Tilley P.Staging methods are useful tools for monitoring disease and response to treatment, and because Severe Equine Asthma Syndrome (SEAS) has a high prevalence in the equine population, a clinical staging method can provide important information to optimize equine care. Our team has previously developed and published a clinical staging method for SEAS and in the present study we further evaluated information provided by lung function tests, in order to determine their contribution to disease staging. Using discriminant analysis we set out to produce a new staging method with applicability in the fie...
McIlwraith CW, Lattermann C.The use of intra-articular corticosteroids for traumatic arthritis and osteoarthritis (OA) is common in the horse. The beneficial and deleterious effects of the principal corticosteroids used betamethasone esters (Celestone [Soluspan], methylprednisolone acetate [Depo Medrol], and triamcinolone acetonide [TA] [Vetalog or Kenalog]) have been defined for the horse. While TA has both disease-modifying as well as symptom-modifying effects, methyl prednisolone acetate has deleterious effects on the articular cartilage. Studies in traumatically injured joints show the same rationale (suppression of ...
Wise LN, Kappmeyer LS, Knowles DP, White SN.The equine parasite Theilera equi continues to curtail global equine commerce due primarily to its ability to persist indefinitely in the immunocompetent horse. Details regarding the parasite life cycle, pathogenesis and mechanism of persistence remain unclear. The recently discovered T. haneyi is also capable of persistence in the horse, creating a potential reservoir for additional infections. These two divergent parasites share a unique gene family that expresses surface merozoite antigens, or equi merozoite antigens (EMAs). The EMA family was maintained in number and size in both parasites...
Peters-Kennedy J, Lange CE, Rine SL, Hackett RP.Equus caballus papillomavirus 8, a recently discovered virus, has been reported to cause generalised papillomavirus in horses. Objective: To describe a case in which multiple viral plaques, viral papillomas, squamous cell carcinoma (SCC) in situ and invasive squamous cell carcinoma (ISCC) were associated with EcPV8 in a horse. Methods: Case report. Methods: A 16-year-old mixed breed horse presented with dozens of raised crusted papular to nodular lesions over a course of 4 years. Masses had been surgically excised four times and cisplatin beads and emulsion were implanted on three different ...
Gibbs C, Lane JG.The radiographic findings in 167 horses subjected to radiography of the facial area, nasal cavity and paranasal sinuses are recorded. Cases were grouped according to clinical diagnosis and the common and disparate radiographic features between and within groups are discussed. Dental disease occurred most frequently and accounted for about 30 per cent of cases, most of which had periapical infection. This disorder presented as two distinct clinical entities in almost equal numbers affected teeth with roots rostral to the maxillary sinus usually produced facial swelling, whereas those with roots...
Cooper LG, Caffe G, Cerutti J, Nielsen MK, Anziani OS.Macrocyclic lactones are the most widely used drugs for the control of gastrointestinal nematodes of horses in Argentina. Ivermectin and moxidectin are used as broad spectrum anthelmintics and although there are several international reports on the resistance of Parascaris spp., the resistance status of the local nematode population is largely unknow. This report informs a case of suboptimal efficacy to both drugs to control Parascaris spp in foals in central Argentina. In February 2018, routine fecal parasite egg counts showed a moderate-high number of Parascaris spp eggs (mean = 680 eggs p...
Thirion-Delalande C, Guillot J, Jensen HE, Crespeau FL, Bernex F.A 6-year-old female pony died after 2 days of prostration. Clinical signs included hyperthermia and abnormal pulmonary auscultation sounds. Necropsy revealed diffuse severe necrohaemorrhagic colitis and splenitis, multiple visceral ecchymoses, petechial haemorrhages in the brain and lungs. Microscopical examination showed acute necrohaemorrhagic colitis, encephalitis, pneumonia and splenitis associated with fibrinoid vasculitis, thrombosis and fungal hyphae within and around vessels. Immunohistologically, concomitant aspergillosis (caused by Aspergillus fumigatus) and mucormycosis (causde by A...
Moore BR, Reed SM, Biller DS, Kohn CW, Weisbrode SE.Magnification of cervical radiographs prevents accurate interpretation of vertebral canal absolute minimum sagittal diameter (MSD) values and application of the established MSD values for diagnosis of cervical stenotic myelopathy (CSM). Variability in MSD determination in human beings, owing to radiographic magnification, is minimized by assessing a ratio of the vertebral canal diameter to the sagittal width of the vertebral body. This relative measurement technique improves the accuracy of diagnosis of cervical spinal stenosis in human beings. The MSD of the vertebral canal was determined in ...
Idoko IS, Edeh RE, Adamu AM, Machunga-Mambula S, Okubanjo OO, Balogun EO, Adamu S, Johnson W, Kappmeyer L, Mousel M, Ueti MW.Equine piroplasmosis, an economically important disease of equids caused by the hemoprotozoan parasites , , and , has a worldwide distribution. These parasites are transmitted by ixodid ticks. To improve the detection of horses in Nigeria exposed to piroplasm parasites, 72 horses with variable clinical signs of piroplasmosis were sampled from Northwest and Northcentral Nigeria and tested by nPCR and cELISA. Blood and serum samples were collected from each horse via jugular venesection. Individually, nPCR or cELISA failed to identify all horses exposed to piroplasms. A combination of species-sp...
Bergero D, Nery J.The concept 'liver disease' includes several pathological conditions affecting liver's functions. It can either consist of a temporary impaired functioning of the liver and/or it can progress to its failure. The purpose of this review is to update the knowledge on hepatobiliary diseases and in particular on equine hyperlipaemia. Hepatobiliary disease's aetiology, clinical signs, diagnosis and nutritional management are thus described in the first part of the review the second part being devoted to hyperlypaemia's lipid metabolism, epidemiology, clinical signs, post-mortem observations and nutr...
Borchers A, Wilkins PA, Marsh PM, Axon JE, Read J, Castagnetti C, Pantaleon L, Clark C, Qura'n L, Belgrave R, Schwarzwald C, Levy M, Bedenice D....Evaluation of serial blood lactate concentrations [LAC] are of prognostic value for morbidity and mortality in critically ill human patients and neonatal foals, but have not been prospectively evaluated in a large multicentre study of critically ill neonatal foals. Objective: To prospectively evaluate the prognostic value of sequential [LAC] analysis in critically ill neonatal foals with risk of mortality. Methods: Prospective, observational study. Methods: Thirteen university and private equine referral hospitals enrolled 643 foals over the 2008 foaling season and [LAC] was measured at admiss...
Dunowska M, Holloway SA, Wilks CR, Meers J.Seventeen New Zealand isolates of equine herpesvirus 5 (EHV-5) were compared to the Australian prototype strain. PCR primers were designed to amplify EHV-5 glycoprotein B (gB) gene, and Restriction Fragment Length Polymorphism (RFLP) was used to detect differences between cloned PCR products. EHV-5 isolates from different horses showed a high degree of heterogeneity. However, EHV-5 isolates from individual horses remained homogeneous when examined over a period of time or isolated from different sites. A single EHV-5 gB RFLP profile was detected in isolates from each individual horse but one. ...
Hedges JF, Balasuriya UB, Ahmad S, Timoney PJ, McCollum WH, Yilma T, MacLachlan NJ.Indirect enzyme linked immunosorbant assays (ELISAs) utilizing the three major structural proteins (M, N, and G(L)) of equine arteritis virus (EAV) expressed from recombinant baculoviruses were developed. A large panel of sera collected from uninfected horses, and from animals experimentally and naturally infected with EAV or vaccinated with the modified live virus vaccine against equine viral arteritis, were used to characterize the humoral immune response of horses to the three major EAV structural proteins. The data suggest that the M protein was the major target of the equine antibody resp...
Beech J, McFarlane D, Lindborg S, Sojka JE, Boston RC.To compare endogenous ACTH and α-melanocyte-stimulating hormone (α-MSH) concentrations after administration of thyrotropin-releasing hormone (TRH) and to compare ACTH concentrations after TRH administration with those following domperidone administration in healthy horses and horses with pituitary pars intermedia dysfunction (PPID). Methods: Prospective case series. Methods: 69 clinically normal horses and 47 horses with or suspected to have PPID. Methods: ACTH concentrations were measured during 108 TRH stimulation tests in 88 horses, and α-MSH concentrations were measured during 56 TRH st...
Dein FJ, Carpenter JW, Clark GG, Montali RJ, Crabbs CL, Tsai TF, Docherty DE.Of 39 captive whooping cranes (Grus americana), 7 died during a 7-week period (Sept 17 through Nov 4, 1984) at the Patuxent Wildlife Research Center, Laurel, Md. Before their deaths, 4 cranes did not develop clinical signs, whereas the other 3 cranes were lethargic and ataxic, with high aspartate transaminase, gamma-glutamyl transferase, and lactic acid dehydrogenase activities, and high uric acid concentrations. Necropsies indicated that the birds had ascites, intestinal mucosal discoloration, fat depletion, hepatomegaly, splenomegaly, and visceral gout. Microscopically, extensive necrosis an...
Tietje S, Becker M, Böckenhoff G.The rapid development of software and technology now allows a large amount of diagnostic information to be obtained from a computed tomographic examination. This imaging technique can also be usefully applied to the horse, given appropriate premises and a custom built table for accurate positioning. Computed tomography of the skull has considerable advantages over other techniques, as structures are viewed without superimposition. Fifteen cases are used to demonstrate how through high image quality (precise detail, reduction in artefacts) and objective measurement of density, various pathologi...
Flaminio MJ, LaCombe V, Kohn CW, Antczak DF.A 12-year-old Quarter Horse mare that was nonresponsive to medical treatment was evaluated for chronic respiratory disease and hepatobiliary disease. Serum immunoglobulin concentrations were measured by use of radial immunodiffusion that revealed trace to nondetectable concentrations of IgG, IgG(T), IgM, and IgA. Use of serum protein electrophoresis confirmed agammaglobulinemia by the absence of the expected peak in the gamma region. In addition, vaccination with tetanus toxoid did not result in specific immunoglobulin production. Flow cytometric analysis of blood lymphocyte subpopulations rev...
Cordeiro Rde A, Bittencourt PV, Brilhante RS, Teixeira CE, Castelo-Branco Dde S, Silva ST, De Alencar LP, Souza ER, Bandeira Tde J, Monteiro AJ....Respiratory infections are a common problem among equines and occur with variable rates of morbidity and mortality. Although some fungal species are considered primary agents of respiratory tract infections in several mammals, their relevance in respiratory diseases of equines is frequently neglected. In the present study, we performed an active search for Candida spp. in the nasal cavity of horses. The presence of Candida spp. was investigated through the use of nasal swabs that were streaked on culture media. These yeasts were identified through physiological testing and their in vitro antif...
Jacks S, Giguère S, Prescott JF.Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in foals but does not induce disease in adult horses. Virulence of R. equi depends on the presence of a large plasmid, which encodes a family of seven virulence-associated proteins (VapA and VapC to VapH). Eradication of R. equi from the lungs depends on gamma interferon (IFN-gamma) production by T lymphocytes. The objectives of the present study were to determine the relative in vivo expression of the vap genes of R. equi in the lungs of infected foals, to determine the recall response of bronchial lymph node (BLN)...
Lear TL, McGee RB.Abnormalities of sexual development causing infertility in horses have been investigated since the early 1970's. Conventional cytogenetic analysis by karyotyping has been the primary tool used to investigate these horses. Abnormalities have a broad range, from a phenotypically normal mare with gonadal dysgenesis to a horse with ambiguous external genitalia and internal male and female organs. Cytogenetic analysis can determine genetic sex but cannot identify mutations or deletions of genes involved in the sex determination pathway. Molecular technologies have been developed to confirm cytogene...
Gold S, Regan CE, McLoughlin PD, Gilleard JS, Wilson AJ, Poissant J.Variability in host resistance or tolerance to parasites is nearly ubiquitous, and is of key significance in understanding the evolutionary processes shaping host-parasite interactions. While ample research has been conducted on the genetics of parasite burden in livestock, relatively little has been done in free-living populations. Here, we investigate the sources of (co)variation in strongyle nematode faecal egg count (FEC) and body condition in Sable Island horses, a feral population in which parasite burden has previously been shown to negatively correlate with body condition. We used the ...
Pease AP, Scrivani PV, Erb HN, Cook VL.Large-colon torsion is a common cause of colic in horses and has a worse prognosis and higher cost than other causes of surgical colic of the large colon. During large-colon torsion, the colon wall becomes thick due to vascular occlusion. Therefore, we hypothesized that detecting increased colon wall thickness during ultrasonography would be an accurate preoperative test for large-colon torsion. The sample population consisted of 42 horses that were admitted for surgical treatment of colic localized to the large colon. The diagnosis was confirmed at surgery or necropsy examination. Twelve (29%...
Terhaar HM, Allbaugh RA, Mochel JP, Sebbag L.To determine total protein content (TPC) and serum albumin levels in the tears of horses with healthy or diseased eyes. Methods: Forty-two horses with healthy eyes and 11 horses with unilateral (n = 10) or bilateral (n = 1) ocular disease. Methods: Each eye underwent an ophthalmic examination including detailed conjunctivitis scoring and tear collection with Schirmer strips. TPC and serum albumin levels were quantified in tear samples and compared among healthy eyes, affected eyes, and contralateral unaffected eyes. The impact of the following variables on lacrimal protein levels were asse...
Rejnö S, Strömberg B.An investigation was made of the pathology of osteochondritis dissecans of young foals and horses with clinical signs of the lesion. A randomly selected material of fetuses and young foals without clinical signs was also examined. It was demonstrated that osteochondritis dissecans is primarily a cartilaginous disease, as previously described in pigs and dogs. Thickening, disturbance of endochondral ossification, degeneration and necrosis of the cartilage were the four main features of osteochondritis dissecans. Cracks and fissures occurred in the degenerated and necrotic parts of the cartilage...
Sleeper MM, Durando MM, Miller M, Habecker PL, Reef VB.Clinical findings in 4 horses with aortic root disease are described. Three of the horses had aneurysms of the right aortic sinus, and in 2 of the 3, the aneurysm ruptured, creating a fistula between the aorta and right ventricle. One of these horses had had a murmur since birth, and the aortic sinus aneurysm may have been a congenital anomaly. In a second horse, the aneurysm may have been an acquired condition that developed secondary to chronic aortic regurgitation. Another horse had a large subendocardial hematoma associated with dissection of blood from the aorta to the interventricular se...
Wang T, Xi C, Yu Y, Liu W, Akhtar MF, Li Y, Wang C, Li L.Equid herpesvirus 8 (EHV-8), also known as asinine herpesvirus type 3 (AHV-3), can cause severe respiratory disease, abortion in mares, and neurological disorders. There is limited information on the prevalence of EHV-8 in donkeys in China. In this study, we investigated EHV-8 infection in donkeys using PCR, resulting in the identification of a field strain, termed EHV-8 SD2020113, which was isolated using RK-13 cells and characterized by high-throughput sequencing and transmission electron microscopy. Our data indicated that 38.7% (457/1180) of donkeys showed the presence of EHV-8 in blood sa...
Leng J, Walton G, Swann J, Darby A, La Ragione R, Proudman C.The intestinal microbiota of the horse, an animal of huge economic and social importance worldwide, is essential to the health of the animal. Understanding the intestinal ecosystem and its dynamic interaction with diet and dietary supplements currently requires the use of experimental animals, with consequent welfare and financial constraints. Here, we describe the development and assessment, using multiple analytical platforms, of a three-vessel, continuous-flow, model of the equine hindgut. After inoculation of the model with fresh horse feces, the bacterial communities established in each ...
Johnson AK, Clark-Price SC, Choi YH, Hartman DL, Hinrichs K.To describe the health status of foals derived by use of somatic cell nuclear transfer (NT) at a university laboratory. Methods: Retrospective case series. Methods: 14 live-born NT-derived foals. Methods: Medical records from 2004 through 2008 were evaluated to identify all pregnancies resulting in live-born NT-derived foals. Information obtained included gestation length, birth weight, foaling complications, gross abnormalities of the fetal membranes, appearance of the umbilicus, mentation of the foal, limb deformities, and any other abnormalities detected in the neonatal period. Clinicopatho...
Holland RE, Schmidt A, Sriranganathan N, Grimes SD, Wilson RA, Brown CM, Walker RD.Serotype, biotype, antibiogram, hemolysin production, fimbrial hemagglutinins, select toxin genes (STb, STaP, LT, slt1 and slt2) and the attaching effacing (eae) gene were determined for 99 foal strains of E. coli. E. coli from diarrheic and normal foals could not be distinguished by serotype, biotype, or antibiogram. Differences (P < or = 0.05) were observed in hemolysin production (11.5% vs 0%) and the expression of mannose-resistant hemagglutinins (23% vs 13%) among E. coli from diarrheic and healthy foals, respectively. Three of the E. coli strains from diarrheic foals were positive wit...
Mead DG, Ramberg FB, Maré CJ.In previous experiments we have demonstrated that colonized and wild black flies are competent laboratory vectors of different Mexican and Western USA isolates of vesicular stomatitis virus, serotype New Jersey (VSV-NJ). We have recently demonstrated biological VSV-NJ transmission by black flies using animal models. In the study described here, we tested the vector competence of colonized and wild black flies for the vesicular stomatitis virus, serotype Indiana (VSV-IN). A 1998 equine isolate was used. After a 10 day incubation period, saliva from experimentally infected Simulium vittatum and ...
Fukushi H, Yamaguchi T, Yamada S.Equine herpesvirus type 9 (EHV-9), which we isolated from a case of epizootic encephalitis in a herd of Thomson's gazelles (Gazella thomsoni) in 1993, has been known to cause fatal encephalitis in Thomson's gazelle, giraffe, and polar bear in natural infections. Our previous report indicated that EHV-9 was similar to the equine pathogen equine herpesvirus type 1 (EHV-1), which mainly causes abortion, respiratory infection, and equine herpesvirus myeloencephalopathy. We determined the genome sequence of EHV-9. The genome has a length of 148,371 bp and all 80 of the open reading frames (ORFs) fo...
Bisgaard M, Piechulla K, Ying YT, Frederiksen W, Mannheim W.Evidence was obtained to indicate that equine strains of organisms previously described as Actinobacillus suis or hemolytic variants of Actinobacillus equuli might constitute a separate group of organisms provisionally designated taxon 11. Four biovars were noticed within taxon 11. Selected DNA:DNA hybridizations support the classification of the mannitol positive biovar 2 of taxon 11 distinct from porcine A. suis. The final taxonomical position of taxon 11, however, has to await more detailed genetic studies including all biovars of taxon 11. A species name has not been suggested for the same...
Hall BG, Faunce W.The genes for utilization of cellobiose are normally cryptic in both laboratory strains and natural isolates of Escherichia coli. A survey of natural isolates of E. coli reveals that functional genes for cellobiose utilization, while rare, are present. The fraction of E. coli that utilized cellobiose ranged from less than 0.01% in human fecal samples to 7% in fecal samples obtained from horses. Samples obtained from sheep, cows, dogs, and pigs contained 0.1 to 0.5% cellobiose-positive E. coli. Neither the previously identified cel genes nor the bgl genes from E. coli K-12 were expressed during...
Leroux AA, Detilleux J, Sandersen CF, Borde L, Houben RM, Al Haidar A, Art T, Amory H.Risk factors for cardiac diseases in horses have not been explored in a large population of animals. Objective: To describe risk factors for various cardiac diseases in a hospital-based population of horses. Methods: Files of 3,434 horses admitted at the Internal Medicine Department of the Liege Equine Teaching Hospital between 1994 and 2011 were reviewed and of those, 284 were categorized as having moderate-to-severe cardiac disease. Methods: Observational study. After calculating prevalence for each cardiac disease, we tested whether breed (chi-square test) or sex, age, body weight (BW), and...
