Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Kuroda T, Kinoshita Y, Niwa H, Shinzaki Y, Tamura N, Hobo S, Kuwano A.Meticillin-resistant Staphylococcus aureus (MRSA) infections have been confirmed in hospitalised Thoroughbred racehorses at the hospitals of two training centres in Japan since 2009. To investigate the source of infection, the authors examined the rate of nasal MRSA colonisation in 600 healthy Thoroughbred racehorses, 53 veterinarians and 16 office staff at the racehorse hospitals of the two training centres. MRSA was not isolated from healthy Thoroughbred racehorses or hospital office staff. However, MRSA was isolated from 16 veterinarians (30.1 per cent), and the colonisation rate was signif...
Zakia LS, Olivo G, Basso RM, Mira J, Herman M, Araujo JP, Borges AS, Oliveira-Filho JP.Aural plaques are a dermatopathy associated with Equus caballus papillomavirus (EcPV). This disease affects horses of all ages, genders and breeds, and causes sensitivity of the ears. Objective: The aim of this study was to evaluate the clinical efficacy of 5% imiquimod cream for the treatment of aural plaques and to compare the PCR detection of EcPV 3, 4, 5 and 6 before and after treatment. Methods: Eight horses diagnosed with aural plaques (14 ears) were used. Three mares with unilateral aural plaques were used as untreated controls. Methods: Imiquimod cream was applied every 48 h until comp...
Zhao J, Negussie H, Laval K, Poelaert KC, Nauwynck HJ.Equine herpesvirus 1 (EHV-1) and equine arteritis virus (EAV) induce respiratory problems and abortion in horses and are considered as two serious threats to equine industry. Both EHV-1 and EAV misuse patrolling leukocytes in the upper respiratory tract to breach the basement membrane (BM) and to migrate to blood vessels. So far, the behavior and impact of a double infection in the respiratory mucosa of a horse are unknown. In the present study, the outcome of double infections with EHV-1 and the low virulent EAV strain 08P187 (superinfection with an interval of 12h or co-infection) were compa...
Andrews ES, Turell MJ.Emerging and re-emerging arboviruses continue to be a threat to global public health, and viral surveillance of mosquito populations is critical for mosquito control operations. Due to the tropical climate of many of the affected areas, it may be difficult to maintain a cold chain as the samples travel from collection sites to laboratories for testing. We determined how suboptimal holding temperatures affected the ability to detect viruses in pools of mosquitoes. Adult female Aedes albopictus and Ae. taeniorhynchus individuals were inoculated with chikungunya virus or Venezuelan equine encepha...
Bassarak B, Moser I, Menge C.A modified Baltz's in vitro cultivation system for the propagation of Trypanosoma equiperdum strain OVI was established to develop a replacement for the conventional production procedure of dourine diagnostic antigen in rats. To increase trypanosome yields we designed an optimized culture medium by addition of supplemental compounds. Trypanosomes were adapted to this medium by two succeeding cultivation steps which led to a substantial proliferation rate and an increased cell density tolerance, respectively. As a result, adapted parasites could be propagated to maximum cell densities of >2...
Peglar MT, Nerad TA, Anderson OR.A new species of lobosean amoeba, Stenamoeba polymorpha n. sp., was isolated from the diarrheic stool of a domesticated horse in Great Falls Virginia, U.S. It shares characteristics with the five other described Stenamoeba species. However, electron microscopy revealed S. polymorpha has a substantially thickened cell surface lamina. Under light microscopy, the amoebae had a dynamic polymorphic appearance because hyaloplasm readily formed and resorbed subpseudopodia from any peripheral region of the cell. While in locomotion, the amoebae produced subpseudopodia that led and alternated the dire...
Cauchard S, Van Reet N, Büscher P, Goux D, Grötzinger J, Leippe M, Cattoir V, Laugier C, Cauchard J.Trypanozoon parasites infect both humans, causing sleeping sickness, and animals, causing nagana, surra, and dourine. Control of nagana and surra depends to a great extent on chemotherapy. However, drug resistance to several of the front-line drugs is rising. Furthermore, there is no official treatment for dourine. Therefore, there is an urgent need to develop antiparasitic agents with novel modes of action. Host defense peptides have recently gained attention as promising candidates. We have previously reported that one such peptide, the equine antimicrobial peptide eCATH1, is highly active a...
Habibi G, Esmaeilnia K, Hablolvarid MH, Afshari A, Zamen M, Bozorgi S.Equine piroplasmosis (EP) is the cause of persistent tick-borne infection with no symptoms, but the most important problem of EP is due to the persistent carrier state. Carrier animals to Babesia (Theileria) equi (Laveran 1901) and B. caballi (Nuttall, 1910) infestation could be identified by extremely sensitive PCR-based method. The purpose of this study was to identify the causative agents of equine piroplasmosis based on molecular and microscopic assays in equids from Kurdistan Province, Iran. Methods: Thirty one horse and mule blood samples were used with history of living in Kurdistan Pro...
Kumar J, Chaudhury A, Yadav SC.Trypanosomosis (Surra) is an economically important disease caused by Trypanosoma evansi which is an extracellular parasite present in the plasma, tissues and other body fluids of a wide range of hosts including domesticated animals. Currently, serological reports are based on detection of antibodies by ELISA using whole cell lysate (WCL) antigen, which has a limitation of persistence of anti-trypanosomal antibodies after successful treatment of the disease. Moreover, it has some ethical issues also like requirement of mice for in vivo maintenance of parasite for preparing the antigen. Therefo...
Sánchez-Matamoros A, Nieto-Pelegrín E, Beck C, Rivera-Arroyo B, Lecollinet S, Sailleau C, Zientara S, Sánchez-Vizcaíno JM.African horse sickness (AHS) is considered a fatal re-emergent vector-borne disease of horses. In the absence of any effective treatment for AHS, vaccination remains the most effective form of disease control. The new generation of vaccines, such as one based on purified, inactivated AHS virus (AHSV, serotype 4), which does not induce antibodies against non-structural protein 3 (NS3), enables the development of diagnostic methods that differentiate infected from vaccinated animals (DIVA assays). As detecting AHS in AHSV-free countries may lead to restrictions on international animal movements ...
Peters M, Grafen J, Kuhnen C, Wohlsein P.A 13-year-old Icelandic crossbred horse was presented with headshaking and progressive impairment of chewing. A slowly growing mass was identified in the anterior maxilla. This was associated with lysis of the alveolar bone and the roots of the incisors and there were nodular proliferations affecting the nasal septum and conchae. There was no response to chemotherapy and so the horse was humanely destroyed. Based on morphological, immunohistochemical and ultrastructural findings the mass was classified as a malignant glomus tumour with multifocal vascular spaces and additional neuroendocrine d...
Davitkov D, Vucicevic M, Stevanovic J, Krstic V, Slijepcevic D, Glavinic U, Stanimirovic Z.Equine piroplasmosis is significant tick-borne disease with wide distribution. The prevalence of equine piroplasmosis in Serbia, Montenegro and Bosnia and Herzegovina is unknown. In aim to obtain a first insight into the prevalence we performed molecular epidemiological study which included 142 horses, on seven locations in these three countries. We first performed PCR for the detection of a 450bp long section of the 18S rRNA of piroplasma-specific region. For all positive samples we have done multiplex PCR for the species detection. Species determination was further confirmed by sequencing PC...
Kennedy R, Lappin DF, Dixon PM, Buijs MJ, Zaura E, Crielaard W, O'Donnell L, Bennett D, Brandt BW, Riggio MP.Equine periodontal disease is a common and painful condition and its severe form, periodontitis, can lead to tooth loss. Its aetiopathogenesis remains poorly understood despite recent increased awareness of this disorder amongst the veterinary profession. Bacteria have been found to be causative agents of the disease in other species, but current understanding of their role in equine periodontitis is extremely limited. The aim of this study was to use high-throughput sequencing to identify the microbiome associated with equine periodontitis and oral health. Subgingival plaque samples from 24 h...
Kalinowski M, Grądzki Z, Jarosz Ł, Kato K, Hieda Y, Kakuda T, Takai S.Rhodococcus equi is an important bacterial pathogen in foals up to 6 months old, widespread in horse farms all over the world. It was found that only virulent R. equi strains expressing 15-17 kDa virulence-associated protein (VapA) and having large virulence plasmid of 85-90 kb containing vapA gene are pathogenic for horses. To date, 12 plasmid types have been reported in VapA positive strains from horses. There are no data concerning plasmid types of Polish field R. equi strains isolated from horses and horse farm environment. The aim of the study is to determine plasmid profiles of virulent ...
Takesue M, Osaka Y, Muranaka M, Katayama Y, Ikadai H.In the present study, the serum and cerebrospinal fluid of horses diagnosed with Setaria digitata cerebrospinal filariasis were analyzed by western blot. The results revealed S. digitata protein bands measuring 65, 34, 22, and 18 kDa in molecular weight. In particular, the 18 kDa band is a possible candidate for clinical immunodiagnosis on the basis of western blot findings.
Jarvis JA, Franke MA, Davis AD.An examination using the routine rabies direct fluorescent antibody test was performed on rabies or Eastern equine encephalitis positive mammalian brain tissue to assess inactivation of the virus. Neither virus was inactivated with acetone fixation nor the routine test, thus laboratory employees should treat all samples as rabies and when appropriate Eastern equine encephalitis positive throughout the whole procedure.
Sherman AB, Clode AB, Gilger BC.To determine the significance of Aspergillus and Fusarium spp., as identified by culture, on clinical outcome in equine keratomycosis. Methods: Retrospective analysis of 66 horses (66 eyes) evaluated at the NCSU-VH diagnosed with keratomycosis from which Aspergillus or Fusarium spp. were cultured. Horses were classified into those who improved with medical management alone or those who required surgical intervention to improve. Horses who underwent surgery were divided into globe-sparing procedures or enucleation. Effects of bacterial co-infection, previous topical steroid or antifungal use, a...
Gardner SN, McLoughlin K, Be NA, Allen J, Weaver SC, Forrester N, Guerbois M, Jaing C.Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne alphavirus that has caused large outbreaks of severe illness in both horses and humans. New approaches are needed to rapidly infer the origin of a newly discovered VEEV strain, estimate its equine amplification and resultant epidemic potential, and predict human virulence phenotype. We performed whole genome single nucleotide polymorphism (SNP) analysis of all available VEE antigenic complex genomes, verified that a SNP-based phylogeny accurately captured the features of a phylogenetic tree based on multiple sequence alignment, an...
Kydd JH, Case R, Winton C, MacRae S, Sharp E, Ricketts SL, Rash N, Newton JR.Identification of risk factors which are associated with severe clinical signs can assist in the management of disease outbreaks and indicate future research areas. Pregnancy loss during late gestation in the mare compromises welfare, reduces fecundity and has financial implications for horse owners. This retrospective study focussed on the identification of risk factors associated with pregnancy loss among 46 Thoroughbred mares on a single British stud farm, with some but not all losses involving equid herpesvirus-1 (EHV-1) infection. In a sub-group of 30 mares, association between pregnancy ...
Information on equine infectious anaemia (EIA) in mules, including those with an equivocal reaction in agar gel immunodiffusion test (AGIDT), is scarce. For this, a study was conducted to evaluate the clinical, viral loads and pathological findings of two groups of naturally infected asymptomatic mules, respectively with a negative/equivocal and positive AGIDT reactivity, which were subjected to pharmacological immune suppression (IS). A non-infected control was included in the study that remained negative during the observation period. Throughout the whole study, even repeated episodes of rec...
Jennings JE.A 21-year-old Appaloosa mare was presented with a pigmented cutaneous mass at the base of the right side of the neck. The diagnosis of phaeohyphomycosis due to pigmented fungi, known as Pyrenophora phaeocomes and Drechslera nobleae, was made based on a histopathology report followed by polymerase chain reaction (PCR) and 18S rRNA gene sequencing. The mass was surgically excised with clean margins, which is usually curative. Une jument Appaloosa âgée de 21 ans a été présentée avec une masse cutanée pigmentée à la base du côté droit du cou. Le diagnostic de phæohyphomycose causée p...
Carfora V, Caprioli A, Grossi I, Pepe M, Alba P, Lorenzetti S, Amoruso R, Sorbara L, Franco A, Battisti A.A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phen...
Terron-Canedo N, Weir W, Nicolson L, Britton C, Nasir L.Bovine papillomavirus (BPV) types 1 and 2 play an important role in the pathogenesis of equine sarcoids (ES), the most common cutaneous tumour affecting horses. MicroRNAs (miRNAs), small non-coding RNAs that regulate essential biological and cellular processes, have been found dysregulated in a wide range of tumours. The aim of this study was to identify miRNAs associated with ES. Differential expression of miRNAs was assessed in control equine fibroblasts (EqPalFs) and EqPalFs transformed with the BPV-1 genome (S6-2 cells). Using a commercially available miRNA microarray, 492 mature miRNAs we...
Martin LM, Johnson PJ, Amorim JR, Honaker AR, Donaldson RS, DeClue AE.Horses affected with gastrointestinal conditions such as colic or colitis are at substantial risk for translocation of bacterial components such as lipopolysaccharide (LPS, endotoxin) from the gastrointestinal tract into circulation resulting in systemic inflammation and subsequent morbidity and mortality. Therefore, there is a need for effective preventive and treatment strategies aimed at minimizing the host's inflammatory reaction to these pathogen-associated molecular patterns (PAMPs) from gastrointestinal disease. Resveratrol (RES, trans-3,5,4'-trihydroxystilbene) is a phytoalexin commonl...
Ayala-Valdovinos MA, Galindo-García J, Sánchez-Chiprés D, Duifhuis-Rivera T.Lethal white foal syndrome (LWFS) is an autosomal recessive disease of neonatal foals characterized by a white hair coat and a functional intestinal obstruction. Traditional techniques for identifying the dinucleotide mutation (TC→AG) of the endothelin receptor B gene (EDNRB) associated with LWFS are time-consuming. We developed a new technique based on mutagenically separated polymerase chain reaction (MS-PCR) for simple detection of the EDNRB genotype in horses.
Carossino M, Lee PY, Nam B, Skillman A, Shuck KM, Timoney PJ, Tsai YL, Ma LJ, Chang HF, Wang HT, Balasuriya UB.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of horses. Most importantly, EAV induces abortion in pregnant mares and can establish persistent infection in up to 10-70% of the infected stallions, which will continue to shed the virus in their semen. The objective of this study was to develop and evaluate a reverse transcription insulated isothermal polymerase chain reaction (RT-iiPCR) for the detection of EAV in semen and tissue samples. The newly developed assay had a limit of detection of 10 RNA copies and a 10-fol...
Gressler LT, Bordin AI, McQueen CM, Cohen ND, de Vargas AC.Rhodococcus equi preferentially infects macrophages causing pyogranulomatous pneumonia in young foals. Both the vapA and rhbC genes are up-regulated in an iron (Fe)-deprived environment, such as that found within macrophages. Chloroquine (CQ) is a drug widely used against malaria that suppresses the intracellular availability of Fe in eukaryotic cells. The main objective of this study was to evaluate the ability of CQ to inhibit replication of virulent R. equi within murine (J774A.1) and foal alveolar macrophages (AMs) and to verify whether the mechanism of inhibition could be Fe-deprivation-d...
Slusarewicz P, Pagano S, Mills C, Popa G, Chow KM, Mendenhall M, Rodgers DW, Nielsen MK.Intestinal parasites are a concern in veterinary medicine worldwide and for human health in the developing world. Infections are identified by microscopic visualisation of parasite eggs in faeces, which is time-consuming, requires technical expertise and is impractical for use on-site. For these reasons, recommendations for parasite surveillance are not widely adopted and parasite control is based on administration of rote prophylactic treatments with anthelmintic drugs. This approach is known to promote anthelmintic resistance, so there is a pronounced need for a convenient egg counting assay...
Erol E, Jackson C, Horohov D, Locke S, Smith J, Carter C.Determination of fetal serum amyloid A (SAA) concentrations in aborted fetuses can provide valuable information regarding the infectious and/or inflammatory process of abortion in horses. To investigate the relationship between fetal SAA levels and the infectious/inflammatory disease process in feto-placental tissues, a SAA ELISA was used to test heart serum samples of 89 equine fetuses that were necropsied and diagnosed in the following groups: a multiorgan disease process diagnosed with an identified microorganism (14 cases, group 1); only placentitis diagnosed with an identified microorgan...
Rosin-Arbesfeld R, Rivlin M, Noiman S, Mashiah P, Yaniv A, Miki T, Tronick SR, Gazit A.Three cDNA clones representing structurally distinct transcripts were isolated from a cDNA library prepared from cells infected with equine infectious anemia virus (EIAV) by using a probe representing the S3 open reading frame, which is thought to encode Rev. One species, designated p2/2, contained four exons and was identical to a previously described polycistronic mRNA that encodes Tat. This transcript was predicted to also direct the synthesis of a truncated form of the transmembrane protein and a putative Rev protein whose N-terminal 29 amino acids, derived from env, are linked to S3 seque...
Timoney JF, Suther P, Velineni S, Artiushin SC.Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were sig...
Reyna-Bello A, García FA, Rivera M, Sansó B, Aso PM.The standardization of ELISA for the detection of anti-Trypanosoma evansi antibodies in naturally and experimentally infected horses is described. Bayesian analysis was used to establish the cutoff between positive and negative sera. In order to determine the assessment of the ELISA test, the results obtained were compared with those from an IFA. A relative sensibility of 98.39%, a specificity of 95.12% and a predictive value of 96.83% were determined. The standardized technique was used to evaluate the antibody production against trypanosome in an experimentally infected equine, in which the ...
Matthee S, Krecek RC, McGeoch MA.The intestinal helminth communities of 8 horses, 12 donkeys, 21 Hartmann's mountain zebras, and 44 Burchell's zebras were compared using the original data from 6 studies in South Africa and Namibia. Necropsy and worm recovery techniques were comparable between the studies. Sixty helminth species (58 nematode, 1 cestode, and 1 trematode species) were recorded. There were significant differences in the helminth community structures of the 4 Equus species. The helminth communities of the 2 closely related zebra subspecies were most similar, and they jointly shared 7 helminth species with donkeys ...
Turan N, Yildirim F, Altan E, Sennazli G, Gurel A, Diallo I, Yilmaz H.The aim of the present study was to investigate abortion storms that occurred in the Marmara region of Turkey in 2008-2009 using a real-time PCR. Two aborted foetuses were necropsied and histo-pathological findings reported herein. Ten lungs, 3 brains and one nasal swab from 10 aborted foetuses, 6 nasal swabs and 3 vaginal swabs from aborting mares were included in this study. EHV-1 was isolated from the lung, liver and brain of 1 aborted foetus. EHV-1 DNA was detected in the lungs, livers and spleens of 2 necropsied foetuses and in 3 lungs from 10 foetuses submitted for diagnosis. A brain fro...
Hansson I, Johansson KE, Persson M, Riihimäki M.Nicoletella semolina, a member of the family Pasteurellaceae, can be isolated from the airways of horses with respiratory disorders. However, its role as a potential or opportunistic pathogen is not clear nor is its presence as part of the normal flora. We therefore investigated the presence and bacterial load of N. semolina in healthy and diseased horses. Samples from a healthy control group were compared with samples from the routine analysis of horses with a clinical history of respiratory disorders. A total of 1770 nose swabs and 1132 tracheal aspirate samples were analysed and subjected t...
Allkofer A, Garvey M, Ryan E, Lyons R, Ryan M, Lukaseviciute G, Walsh C, Venner M, Cullinane A.This study compared concurrent and separate primary vaccination against equid alphaherpesviruses 1 and 4, genus Varicellovirus, subfamily Alphaherpesvirinae, family Herpesviridae, and equine influenza A virus, genus Alphainfluenzavirus, family Orthomyxoviridae. Their vernacular names are equine herpesvirus 1 and 4 (EHV1/4) and equine influenza virus (EIV). Infection with these respiratory pathogens is associated with loss of performance, interruption of training schedules, and on occasion, cancellation of equestrian events. Vaccination is highly recommended, and for some activities it is a man...
Wyatt CR, Magnuson NS, Perryman LE.Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed b...
Bryan J, Leonard N, Fanning S, Katz L, Duggan V.The objective of this study was to examine the impact of hospitalisation and antimicrobial drug administration on the prevalence of resistance in commensal faecal E. coli of horses. Faecal samples were collected from ten hospitalised horses treated with antimicrobials, ten hospitalised horses not treated with antimicrobials and nine non-hospitalised horses over a consecutive five day period and susceptibility testing was performed on isolated E. coli. Results revealed that hospitalisation alone was associated with increased prevalence of antimicrobial resistance and multidrug resistance in com...
Burk SV, Dangoudoubiyam S, Brewster-Barnes T, Bryant UK, Howe DK, Carter CN, Vanzant ES, Harmon RJ, Kazacos KR, Rossano MG.Currently, diagnosis of Parascaris equorum infection in equids is limited to patent infections. The goals of this study were to culture P. equorum larvae in vitro and identify excretory-secretory (ES) products for prepatent diagnostic testing. Parascaris equorum L2/L3 larvae were hatched and cultured for up to 3 weeks for ES product collection. Fifth stage (L5) P. equorum were also cultured for ES product collection. Examination of ES fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver stain revealed L2/L3 products ranging from 12-94 kDa and L5 products...
Pusterla N, Hussey SB, Mapes S, Leutenegger CM, Madigan JE, Ferraro GL, Wilson WD, Lunn DP.The objective of the current study was to compare the performance of 4 methods to quantify Equid herpesvirus 1 (EHV-1) by real-time polymerase chain reaction (PCR) in nasal secretions from experimentally and naturally infected horses. Nasal secretions were collected on the challenge day and daily thereafter for 13 days from 4 experimentally infected horses. Additional nasal swabs were collected from 30 horses with clinical signs consistent with natural EHV-1 infection. Absolute quantitation of EHV-1 target molecules was performed using standard curves for EHV-1 and equine glyceraldehyde-3-phos...
Guimarães-Ladeira CV, Palhares MS, Oliveira JS, Ramirez MA, Guedes RM.Proliferative enteropathy, caused by the intracellular bacterium Lawsonia intracellularis, has been described in horses in Australia, the USA, Canada and European countries but has not been reported in Latin America. The prevalence of the disease in horses worldwide is unknown. Objective: To evaluate the presence of subclinical L. intracellularis infection in horses in the state of Minas Gerais, Brazil. Methods: A longitudinal study using serology and PCR for detecting antibodies (IgG) and shedding of L. intracellularis in faecal samples, respectively, was conducted using a total of 223 horses...
Masatani T, Takashima Y, Takasu M, Matsuu A, Amaya T.The present study is the first report that investigated the seroprevalence of Toxoplasma gondii infection in domestic horses in various prefectures of Japan and analyzed risk factors for seropositivity. We performed a latex agglutination test for riding/racing horses from 11 prefectures in Japan (783 samples) and 4 groups of Japanese native horses (254 samples). The total seroprevalence of anti-T. gondii antibody in horses examined in this study was 4.24% (44/1037). As for riding/racing horses, we did not find a statistically different T. gondii seroprevalence between sampling prefectures. In ...
Ainsworth DM, Weldon AD, Beck KA, Rowland PH.Five 3-month-old foals presenting with fever and respiratory disease were found to have pulmonary abscesses with patchy to diffuse alveolar and interstitial pneumonia on post-mortem examination. All affected foals had evidence of Rhodococcus equi infection and had few to abundant Pneumocystis carinii cysts in the sections of affected lung. Of the 5 foals examined radiographically, 3 had a distinct reticulonodular (miliary) pattern which may aid in the ante-mortem diagnosis of P. carinii pneumonia (PCP). Leukocyte counts of foals with PCP were significantly greater than in the control group of ...
Dallap Schaer BL, Epstein K.To review the hemostasis literature relevant to development of coagulopathy in the critically ill equine patient. Methods: Original scientific and review articles. Results: Inflammation plays a critical role in the activation and amplification of clot formation, as well as the impairment of physiologic anticoagulant mechanisms, and fibrinolysis. Earlier identification of coagulopathy in patients at risk and restoration of physiologic hemostasis may result in better outcome. Development of scoring systems based on information other than coagulation markers alone may better identify patients wit...
McTaggart C, Yovich JV, Penhale J, Raidal SL.Flow cytometric assays were used to compare phagocytic and oxidative burst activity of neutrophils from healthy foals less than 7 days of age with the activity of cells from healthy adult horses. The phagocytosis of Staphylococcus aureus by foal neutrophils was less than that observed for adult neutrophils when autologous serum was used as the source of opsonins in the assay. The use of adult serum did not significantly improve the ability of foal neutrophils to attach bacteria. The oxidative burst activity of foal neutrophils was equivalent to that of adult cells. However, when serum or plasm...
Cymerys J, Dzieciatkowski T, Słońska A, Bierla J, Tucholska A, Chmielewska A, Golke A, Bańbura MW.Equine herpesvirus-1 (EHV-1) infections cause significant economic losses for equine industries worldwide as a result of abortion, respiratory illness, and neurologic disease in all breeds of horses. The occurrence of abortions caused by EHV-1 has repeatedly been confirmed in Poland, but neurological manifestations of the infection have not been described yet. Also it is unknown how the infection of neurons with non-neuropathogenic strains is regulated. To further understand the virus-neuron interaction we studied two strains of EHV-1 in murine primary neuron cell cultures. Both strains were i...
Passamonti F, Vardi DM, Stefanetti V, Marenzoni ML, Prato S, Cévese P, Coletti M, Pepe M, Casagrande Proietti P, Olea-Popelka F.Early diagnosis and prevention of Rhodococcus equi pneumonia in foals represent important goals for equine clinicians. Recent protocols for diagnosis and treatment of Rhodococcosis in foals typically rely on a multimodal approach based on sonographic evidence suggestive of pyogranulomas, sonographic abscess scores and laboratory findings including plasma fibrinogen concentrations, blood biochemistry testing and platelet and leukocyte counts. The aim of this study was to assess the utility of weekly testing of serum amyloid A (SAA) and plasma fibrinogen concentrations in foals to achieve early ...
Tandon R, Kaplan RM.A larval development assay (LDA, DrenchRite) was evaluated to determine the effectiveness of this method in detecting anthelmintic resistance in cyathostomin nematodes of horses. A total of 15 horse farms from Georgia and South Carolina (USA) and Population S ponies from the University of Kentucky (USA) were included in this study. Nematode eggs were extracted from pooled fecal samples and placed into the wells of a DrenchRite plate for testing against thiabendazole (TBZ), levamisole (LEV) and 2 ivermectin (IVM) analogs (IVM-1, IVM-2). After a 7-day incubation larvae in each well were counted ...
Hunyadi L, Sundman EA, Kass PH, Williams DC, Aleman M.Immune-mediated myositis (IMM) is a cause of rhabdomyolysis, stiffness, and muscle atrophy predominantly affecting Quarter horses. Limited information is available with regard to outcome, prognostic indicators, and associations with concurrent diseases. Objective: To report outcomes and associations between outcome and clinical and laboratory parameters, and presence of concurrent illness. Methods: Sixty-eight horses; 52 Quarter horses and related breeds and 16 other breeds. Methods: Retrospective cohort study (1991-2014). Medical records of horses with histological diagnosis of IMM were revie...
Magdesian KG, Dujowich M, Madigan JE, Hansen LM, Hirsh DC, Jang SS.To determine molecular characteristics, antimicrobial susceptibility, and toxigenicity of Clostridium difficile isolates from horses in an intensive care unit and evaluate associations among severity of clinical disease with specific strains of C difficile. Methods: Prospective study. Methods: 130 horses. Methods: Feces were collected from horses admitted for acute gastrointestinal tract disease with loose feces and submitted for microbial culture and immunoassay for toxin production. Polymerase chain reaction assays were performed on isolates for toxins A and B genes and strain identification...
Prescott JF, Ogilvie TH, Markham RJ.A lymphocyte stimulation test using antigens of Corynebacterium equi was used to compare the response of peripheral blood lymphocytes from foals with C equi pneumonia with those of clinically normal foals and adult horses. The test clearly distinguished infected foals from normal foals when tested in animals less than or equal to 2 months old. After the 2nd month, stimulation response from individual normal foals sometimes exceed those from infected foals, but mean stimulation response to C equi antigens was significantly (P less than 0.025) greater in 3- to 5-month-old infected foals when com...
Sydor T, von Bargen K, Becken U, Spuerck S, Nicholson VM, Prescott JF, Haas A.Rhodococcus equi is a mucoid Gram-positive facultative intracellular pathogen which can cause severe bronchopneumonia in foals and AIDS patients. A polysaccharide capsule which gives R. equi a mucoid appearance has long been suspected to be a virulence factor. Here, we describe a transposome mutant in the gene fbpA of strain R. equi 103 causing absence of a capsular structure. FbpA is a chromosomal gene homologous to antigen 85 (Ag85) mycolyl chain transferase gene of Mycobacterium tuberculosis. The mutant multiplied normally in isolated macrophages, was able to establish the unusual R. equi-c...
Foote CE, Love DN, Gilkerson JR, Wellington JE, Whalley JM.A silent cycle of equine herpesvirus 1 infection was described following epidemiological studies of unvaccinated mares and foals on a Hunter Valley stud farm. Following the introduction of routine vaccination with an inactivated whole virus equine herpesvirus 1 (EHV-1) and equine herpesvirus 4 (EHV-4) vaccine in 1997, a subsequent study identified excretion of EHV-1 and EHV-4 in nasal swab samples tested by PCR from vaccinated mares and their unweaned, unvaccinated foals. The current sero-epidemiological investigation of vaccinated mares and their young foals found serological evidence of EHV-...
Ramos-Vara JA, Ortiz-Santiago B, Segalès J, Dunstan RW.This report contains the clinical, histologic, immunohistochemical, and electron microscopic findings in two cases of equine cutaneous leishmaniasis. Nodular, sometimes crusty or ulcerated lesions were confined to the pinna and adjacent neck in both animals. The dermal inflammatory infiltrate was lymphohistiocytic in horse No. 1 and pyogranulomatous with formation of tuberculoid granulomas in horse No. 2. Numerous Leishmania organisms were found within macrophages in both animals. There was moderate to intense and specific reaction by immunoperoxidase using a polyclonal antiserum against Leish...
Parashar R, Singla LD, Gupta M, Sharma SK.The haemato-biochemical indices and oxidative stress markers in horses naturally infected with Trypanosoma evansi were evaluated by analyzing the level of these parameters between T. evansi infected (microscopically positive patent group and PCR positive latent group) and infection free horses. To compare the hemato-biochemical indices and oxidative stress indicators, horses were divided into three categories based on diagnostic test employed and positive results obtained. These included Romanowsky stained slide positive group (Group I; n = 6), PCR positive group (group II; n = 28) and negativ...
Sweeney CR, Benson CE, Whitlock RH, Meirs DA, Barningham SO, Whitehead SC, Cohen D.The age-specific attack rates of Streptococcus equi infections of the upper respiratory tract and lymph nodes (strangles) in horses for the different age groups were 17.6% for broodmares, 47.5% for 1-year-old horses, and 37.5% for foals. Streptococcus equi was isolated from nasal, pharyngeal, or lymph node specimens in 31 (60.8%) of 51 sick horses. A male 1-year-old horse, shipped from Kentucky to farm A, was considered to be the index case. Six (19.4%) of 31 horses with strangles remained as shedders of S equi after clinical signs of the disease had ended. Shedders of S equi were not identifi...
Singha H, Gulati BR, Kumar P, Singh BK, Virmani N, Singh RK.The complete genome of the Japanese encephalitis virus (JEV) strain JEV/eq/India/H225/2009(H225), isolated from an infected horse in India, was sequenced and compared to previously published JEV genomes. H225 genome was 10,977-nucleotides long, comprising a single ORF of 10,299-nucleotides, a 5'-UTR of 95 nucleotides and a 3'-UTR of 582 nucleotides. The H225 genome showed high levels of sequence identity with 47 fully sequenced JEV genomes, ranging from 99.3 % to 75.5 % for nucleotides and 99.2 % to 91.5 % for amino acid sequences. Phylogenetic analysis of the full-length sequence indicated th...
Chaffin MK, Cohen ND, Martens RJ, Edwards RF, Nevill M, Smith R.Rhodococcus equi causes severe pyogranulomatous pneumonia in foals and in immunocompromised people. In mice, both CD4+ and CD8+ T lymphocytes contribute to host defense against R. equi, but CD4+ T lymphocytes are required for pulmonary clearance of the bacteria. In this prospective study of 208 foals at two equine breeding farms with endemic R. equi infections, we collected peripheral blood samples at 2 and 4 weeks of age and at the time of diagnosis of R. equi pneumonia. Samples were analyzed for concentrations of total and differential leukocytes, EqCD4+ and EqCD8+ T lymphocytes, and B lymph...
Thieulent C, Hue ES, Sutton G, Fortier C, Dallemagne P, Zientara S, Munier-Lehmann H, Hans A, Paillot R, Vidalain PO, Pronost S.Equid herpesvirus-1 infections cause respiratory, neurological and reproductive syndromes. Despite preventive treatments with vaccines, resurgence of EHV-1 infection still constitutes a major threat to equine industry. However, no antiviral compound is available to treat infected horses. In this study, 2891 compounds were screened against EHV-1 using impedance measurement. 22 compounds have been found to be effective in vitro against EHV-1. Valganciclovir, ganciclovir, decitabine, aphidicolin, idoxuridine and pritelivir (BAY 57-1293) are the most effective compounds identified, and their antiv...
