Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Bublot M.Until recently, Influenza was considered as a veterinary problem in avian, swine and horse only. New influenza strains able to infect and cause a disease in dogs and cats emerged these last six years. The most widely used influenza veterinary vaccines are the inactivated adjuvanted vaccines which are based on whole or split virus. New technologies have allowed the development of new generation vaccines including modified-live and vector vaccines. Modified-live influenza vaccines are available for horses only but they are in development in other species. Vector vaccines are already in use in ch...
Wolf TM, Gandolf AR, Dooley JL, Atkinson MW, Wolfe BA.Vaccination has been an important component of preventative health care programs of North American zoologic institutions in their protection of valuable species against West Nile virus (WNV) infection since its detection in 1999. Although approved only for horses, commercial WNV vaccine has been used for the purpose of protection of nondomestic species, including avian, equid, and rhinoceros species. Currently, there are two commercial equine vaccines available, a killed vaccine and a recombinant viral-vectored vaccine. Both products have been used for the vaccination of Greater One-horned rhi...
Müller I, Pinto E, Santibáñez MC, Celedón MO, Valenzuela PD.The equine influenza virus is the causal agent of influenza in horses. In July 2006, horses from various regions of Chile presented fever, serious nasal discharge, dry cough, anorexia and depression. Here we describe the isolation and characterization of the virus responsible for this outbreak. The virus was identified as equine influenza virus H3N8, since haemagglutination was inhibited by an anti-A/equi/1/H3N8 serum, but not by an anti-A/equi/1/H7N7 serum. The isolate was named A/equi/2/Lonquén/06 (H3N8). In addition, we describe the isolation and sequencing of the haemagglutinin, neuramini...
Walther B, Monecke S, Ruscher C, Friedrich AW, Ehricht R, Slickers P, Soba A, Wleklinski CG, Wieler LH, Lübke-Becker A.Despite the increasing importance of methicillin-resistant Staphylococcus aureus (MRSA) in veterinary medicine, knowledge about the epidemiology of the pathogen in horses is still poor. The phylogenetic relationship of strains of human and equine origins has been addressed before, usually by analyzing results of common standard classification methods for MRSA. This work intends to go beyond the baseline of typing procedures in order to comparatively characterize equine and human MRSA strains with similar phylogenetic backgrounds. In addition to multilocus sequence typing, pulsed-field gel elec...
Matthews AG.This paper overviews some recent developments in mammalian corneal immunobiology, and discusses how these may act as pointers towards understanding the immunology underlying some common corneal diseases in the horse, including infectious ulceration and presumptively immune-mediated non-ulcerative disease. Specifically, three aspects of corneal immunobiology are examined: the role of Toll-like receptors in surface immunity and in the etiogenesis of microbial ulceration, the relationship between conjunctiva associated lymphoid tissue (CALT) and immunoprotection of the corneal surface, and the me...
Black WD, Hartley CA, Ficorilli NP, Studdert MJ.Equine rhinitis B virus (ERBV), genus Erbovirus, is most closely related to the Cardiovirus genus in the family Picornaviridae. The structural proteins (VP1-4) of erboviruses are not well described, but are predicted by sequence to be 35, 29, 26 and 7 kDa. Methods for the purification of cardioviruses (polyethylene glycol, trypsin treatment) were used to characterise the structural proteins of ERBV1. Only one of the virus proteins detected was an expected molecular mass, and this 26 kDa protein was identified as VP3 by N-terminal amino acid sequencing. N-terminal sequencing of the 56 and a 29 ...
Ciscotto P, Machado de Avila RA, Coelho EA, Oliveira J, Diniz CG, Farías LM, de Carvalho MA, Maria WS, Sanchez EF, Borges A, Chávez-Olórtegui C.Venoms from the bee Apis mellifera, the caterpillar Lonomia achelous, the spiders Lycosa sp. and Phoneutria nigriventer, the scorpions Tityus bahiensis and Tityus serrulatus, and the snakes Bothrops alternatus, Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Bothrops neuwiedi, Crotalus durissus terrificus, and Lachesis muta were assayed (800mug/mL) for activity against Staphylococcus aureus. Venoms from B. jararaca and B. jararacussu showed the highest S. aureus growth inhibition and also against other Gram-positive and Gram-negative bacteria. To characterize the microbicidal compon...
Morita H, Shiratori C, Murakami M, Takami H, Toh H, Kato Y, Nakajima F, Takagi M, Akita H, Masaoka T, Hattori M.Four bacterial strains, designated ST18(T), HM244, HM250 and DI49, were isolated from the fresh faeces of four thoroughbred horses in Japan. Cells were Gram-positive, strictly anaerobic, catalase-negative, non-spore-forming, non-motile rods that occurred in chains. They were placed in the same subcluster based on 16S rRNA gene sequence analysis, phenotypic characteristics and levels of DNA-DNA relatedness. Their DNA G+C content ranged from 36 to 38 mol%. Lactobacillus catenaformis, Lactobacillus vitulinus and Catenibacterium mitsuokai belong to cluster XVII of the Clostridium subphylum. Strain...
Cochet M, Vaiman D, Lefèvre F.Interferons (IFNs) are cytokines of vertebrates with many biological effects including antiviral, immunoregulatory and antiproliferative activities. Among them, mammalian type I IFNs represents a large family of related proteins, mainly virus-inducible, divided in 10 distinct subfamilies named alpha, beta, omega, delta, epsilon, alphaomega, nu, tau, kappa and zeta (or Limitin). Some type I IFN subfamilies are physiologically expressed by the conceptus during early pregnancy in ungulates. This is the case in ruminants with IFN-tau (which triggers the maintenance of the maternal corpus luteum du...
Traversa D, Otranto D.Dogs, cats, and horses are popular pets in many countries of the World and they have lived in close proximity with human beings for thousands of years. The effect of pet ownership on human health is well known and there is significant merit in preserving the health and welfare of these animals. Some infections caused by parasitic nematodes and arthropods of dogs, cats, and horses are now spreading in several areas of the world. This is the case of canine spirocercosis, feline aelurostrongylosis, and equine gastro-intestinal and nasal nematode and botfly infections. These diseases affect animal...
Baker A, Plummer CE, Szabo NJ, Barrie KP, Brooks DE.To determine the concentration of doxycycline in preocular tear film following oral administration in horses as a possible therapeutic modality for infectious and keratomalacic equine keratitis. Methods: Eight broodmares without ocular disease from a Thoroughbred breeding facility were included in this study. Each mare received 20 mg/kg of doxycycline by mouth once daily in the morning for five consecutive days. Tears were collected 1 h after doxycycline administration starting on day one of administration and continuing for 10 consecutive days. Doxycycline levels in the tears were measured us...
Allen GP.To identify risk factors associated with development of clinical neurologic signs in horses exposed to equine herpesvirus-1 (EHV-1). Methods: 36 adult horses. Methods: Blood samples collected before and after challenge inoculation with nonneuropathogenic or neuropathogenic EHV-1 were analyzed for leukocyte-associated viremia, serum neutralizing antibody, and EHV-1-specific cytotoxic T-lymphocyte precursors (CTLPs). Associations between variables and neurologic disease and correlations between age category or breed and development of neurologic disease were examined. Results: 9 horses developed...
Yang DK, Kim BH, Kweon CH, Nah JJ, Kim HJ, Lee KW, Yang YJ, Mun KW.Recent global warming trends may have a significant impact on vector-borne viral diseases, possibly affecting vector population dynamics and disease transmission. This study measured levels of hemagglutination-inhibition (HI) antibodies against Japanese encephalitis virus (JEV) and neutralizing antibodies against Akabane virus (AKAV) and Aino virus (AINV) for Thoroughbred horses in Korea. Blood samples were collected from 989 racehorses in several provinces, between October 2005 and March 2007. Sera were tested using either an HI assay or a virus neutralization test. Approximately half (49.7%;...
Mori A, De Benedictis P, Marciano S, Zecchin B, Zuin A, Zecchin B, Capua I, Cattoli G.Equine rhinitis A and B viruses (ERAV and ERBV) are respiratory viruses of horses belonging to the family Picornaviridae. Although these viruses are considered to cause respiratory disease in horses and are potentially infectious for humans, little is known about their prevalence and pathogenesis. Virus isolation is often unsuccessful due to their inefficient growth and lack of cytopathic effect in cell cultures. Therefore, molecular assays should be considered as the method of choice to detect infection in symptomatic or apparently healthy horses. In the present study, a novel real-time duple...
Kharchenko V, Kuzmina T, Trawford A, Getachew M, Feseha G.Fourth-stage larvae of four species of the Cyathostominae Nicoll, 1927 parasitic in donkeys Equus asinus L. from Ethiopia were identified mainly using moulting specimens. They are Cylicocyclus asini Matthee, Krecek & Gibbons, 2001, C. auriculatus (Looss, 1900) Chaves, 1930, Cyathostomum tetracanthum (Mehlis, 1831) Molin, 1861 (sensu Looss, 1900) and Cylindropharynx brevicauda Leiper, 1911. The larva of Cylicocyclus asini is similar to those of C. nassatus (Looss, 1900) Chaves, 1930 and C. leptostomum Kotlán, 1920, but differs from the former by the shape of the dorsal tooth in the oesopha...
Corona A, Cherchi R.Bacteriological surveillance is little applied in management of equine frozen semen but it is quite important to verify the microbial contamination in order to find out the chance of transmission of pathology to the mare in AI. Authors describe a qualitative and quantitative analysis for bacterial contamination on long time (3-17 years) equine frozen semen stored in liquid nitrogen. The semen checked, produced in Italy and in another Europe country, was cryopreserved in liquid nitrogen inside sealed plastic straws. One hundred and ten straws were checked out for pathogenic and no pathogenic ba...
Cuny C, Strommenger B, Witte W, Stanek C.During 2006 and 2007 small clusters of methicillin-resistant Staphylococcus aureus (MRSA) infections in horses were recorded in different clinical departments of a veterinary university. The infections were caused by different MRSA clones (ST1, ST254, and ST398). In the same time, nasal colonization of veterinarians, veterinary personnel, and students was observed indicating transmission to humans.
Ward MP, Wittich CA, Fosgate G, Srinivasan R.West Nile Virus (WNV) was first detected in the Texas equine population during June 2002. Infection has since spread rapidly across the state and become endemic in the equine population. Environmental risk factors associated with equine WNV attack rates in Texas counties during the period 2002 to 2004 were investigated. Equine WNV attack rates were smoothed using an empirical Bayesian model, because of the variability among county equine populations (range 46-9,517). Risk factors investigated included hydrological features (lakes, rivers, swamps, canals and river basins), land cover (tree, mos...
Hassan AA, Ulbegi-Mohyla H, Kanbar T, Alber J, Lämmler C, Abdulmawjood A, Zschöck M, Weiss R.The present study was designed to characterize phenotypically and genotypically seven Arcanobacterium haemolyticum strains obtained from infections of six horses. All seven strains showed the cultural and biochemical properties typical of A. haemolyticum and were susceptible to most of the antibiotics tested. The species identification could be confirmed by amplification and sequencing of the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region and by PCR amplification of species-specific parts of the gene encoding phospholipase D in A. haemolyticum. Use of the latter could possibly imp...
De Souza PN, Bomfim TC, Huber F, Abboud LC, Gomes RS.To detect Cryptosporidium sp., Giardia sp. and Eimeria leuckarti in horses, fecal samples were collected from three different handling horse groups from the state of Rio de Janeiro, Brazil. Group A was composed of "Mangalarga Marchador" pure breed horses, Group B was formed by horses of a Military Corporation and Group C by stray horses captured by the Center of Zoonosis Control Paulo Dacorso Filho. A total of 396 fecal samples were collected, 212 samples from Group A, 154 samples from Group B and 30 from Group C. The material was submitted to the centrifugation - flotation technique and stain...
Hobson-Peters J, Toye P, Sánchez MD, Bossart KN, Wang LF, Clark DC, Cheah WY, Hall RA.Using a monoclonal antibody directed to domain I of the West Nile virus (WNV) envelope (E) protein, we identified a continuous (linear) epitope that was immunogenic during WNV infection of horses. Using synthetic peptides, this epitope was mapped to a 19 aa sequence (WN19: E147-165) encompassing the WNV NY99 E protein glycosylation site at position 154. The inability of WNV-positive horse and mouse sera to bind the synthetic peptides indicated that glycosylation was required for recognition of peptide WN19 by WNV-specific antibodies in sera. N-linked glycosylation of WN19 was achieved through ...
Mongoh MN, Dyer NW, Stoltenow CL, Khaitsa ML.We identified the risk factors associated with the anthrax outbreak Of 2005 in animals in North Dakota. Methods: Medical records of the 2005 anthrax outbreak were obtained from the Veterinary Diagnostic Laboratory at North Dakota State University. Additional data were obtained from the North Dakota state veterinarian's office, and supplemental questionnaires were administered to producers. The data obtained included ecological and environmental factors, animal health factors, and management factors. Results: Anthrax occurred from July 1 to October 12, 2005. The cases were located in eastern No...
Heinrich A, Riethmüller D, Gloger M, Schusser GF, Giese M, Ulbert S.Equine Arteritis Virus (EAV) belongs to the Arteriviridae and causes viral arteritis in horses. In an attempt to develop novel and save therapies against the infection it was tested whether EAV is susceptible to RNA interference (RNAi) in an equine in vitro system. Horse cells were transfected with chemically synthesized small interfering RNA oligonucleotides (siRNAs) and challenged with EAV. Application of these siRNAs led to a significant protection of the cells, and virus titers decreased drastically. siRNAs derived from DNA plasmids expressing small hairpin RNAs (shRNAs) were also effectiv...
Ghanem YM, Fukushi H, Ibrahim ES, Ohya K, Yamaguchi T, Kennedy M.Viruses related to equine herpesvirus type 1 (EHV-1) were isolated from an aborted fetus of an onager (Equus hemionus) in 1984, an aborted fetus of Grevy's zebra (Equus grevyi) in 1984 and a Thomson's gazelle (Gazella thomsoni) with nonsuppurative encephalitis in 1996, all in the USA. The mother of the onager fetus and the gazelle were kept near plains zebras (Equus burchelli). In phylogenetic trees based on the nucleotide sequences of the genes for glycoproteins B (gB), I (gI), and E (gE), and teguments including ORF8 (UL51), ORF15 (UL45), and ORF68 (US2), the onager, Grevy's zebra and gazell...
Gardiner DW, Teifke JP, Podell BK, Kamstock DA.An 18-year-old Arabian stallion was presented for recent onset of stranguria. Physical examination of the distal portion of the glans penis revealed multiple, smooth, glistening, grayish-pink, variably sized, exophytic, nodular masses circumferentially surrounding the external urethral orifice. Partial penile amputation was performed, and the entire specimen was submitted for histological evaluation. Microscopically, the masses consisted of abundant amounts of loosely arranged fibrovascular stroma with low numbers of spindloid to stellate fibrocytes. The overlying epithelium was mildly to mode...
Vengust M, Wen X, Bienzle D.A 4-year-old donkey was evaluated for progressive neurological abnormalities consisting of depression, stupor, weakness, and recumbency. Diagnostic evaluation for viral involvement identified an asinine herpesvirus in DNA extracted from deep pharyngeal swabs. Specific primers were designed based on comparison with equine herpesviral DNA polymerase sequences and yielded an 875-base pair product from the donkey. This sequence had complete identity with short sequences of asinine herpesvirus previously identified in donkeys with interstitial pneumonia. Amino acid analysis of the entire sequence i...
Coffman EA, Abd-Eldaim M, Craig LE.A pregnant 18-year-old Quarterhorse mare presented with fever, anorexia, tachycardia, tachypnea, and gastrointestinal hypermotility at day 68 of gestation. Potomac horse fever was diagnosed based on polymerase chain reaction (PCR) analysis of whole blood and a high antibody titer to Neorickettsia risticii. The mare made a rapid clinical recovery following antibiotic therapy, but aborted 98 days later. Necropsy on the aborted fetus revealed lymphohistiocytic colitis, lymphadenitis, myocarditis, and hepatitis. The placenta was grossly and histologically normal. Formalin-fixed lymph node, thymus,...
Onyiche TE, Sivakumar T, Tuvshintulga B, Nugraha AB, Ahedor B, Mofokeng L, Luka J, Mohammed A, Mbaya AW, Biu AA, Yokoyama N, Thekisoe O.Equine piroplasmosis is caused by apicomplexan parasites, namely, and , which are transmitted to equids principally through ticks. To ascertain the exposure of equines to agents of equine piroplasms, we tested serum samples collected from horses (n = 272) and donkeys (n = 170) in North-Western Nigeria for the presence of antibodies against and using IFAT and ELISA. The seroprevalence of in the horses determined using IFAT and ELISA was 48.89% and 45.96%, respectively, while for , it was 6.3% and 0.4%, respectively. For , the seroprevalence based on IFAT and ELISA results in donkeys was...
Sheoran AS, Timoney JF, Tinge SA, Sundaram P, Curtiss R.The aim of this study was to investigate the intranasal immunogenicity for the horse of a Deltacya Deltacrp-pabA mutant (MGN-707) of Salmonella enterica serotype Typhimurium (S. typhimurium). MGN-707 caused no sign of disease, was not detected in feces and a single administration induced strong Salmonella-specific serum and nasal mucosal antibody responses. All ponies had made strong salmonella specific serum IgGa, IgGb, IgA and IgM antibody responses by day 25 after the first immunization. IgM responses to salmonella lipopolysaccharide (LPS) were short lived whereas salmonella specific serum ...
Divers TJ.Nephrotoxic and hemodynamically mediated disorders are the most common causes of acute renal failure (ARF) in horses and foals. Leptospira spp. is the most common infectious cause of ARF. Initial treatments for ARF include elimination of nephrotoxic drugs, correction of predisposing disorders, and fluid therapy to promote diuresis. Horses and foals with polyuric ARF often have a good prognosis, while those with oliguric or anuric ARF have a guarded to poor prognosis. When fluid therapy is unsuccessful in improving urine production, various drugs treatments have been used in an attempt to incre...
Alzuheir I, Fayyad A, Jalboush N, Abdallah R, Abutarbush S, Gharaibeh M, Bdarneh M, Khraim N, Helal MA, Helal BA.West Nile fever (WNF) is a neurotropic, mosquito-borne disease affecting humans and domesticated animals, caused by a member of the genus . Over the last decades, this virus has been responsible for several cases of illness in humans and animals. The current epidemiological status of WNF in horses is insufficient, and in veterinarians, as an occupational hazard is unknown. This study aimed to investigate and determine the seroprevalence and risk factors for WNF in veterinarians and horses in Palestine. Methods: In this study, serum samples from 100 veterinarians and 87 horses were collected be...
Sumbria D, Singla LD, Sharma A, Bal MS, Randhawa CS.Equine piroplasmosis caused by Theileria equi, an apicomplexan intracellular haemoprotozoan parasite effects equids throughout the world. Current investigation is the first detailed epidemiological survey report based on conventional (blood smear) and primary polymerase chain reaction (PCR) for the detection of T. equi on 464 equids (426 horses and 38 donkeys/mules) in Punjab province of India. PCR targeting 18S rRNA gene of T. equi produced high fidelity 709bp amplification products with 100% concordance with blood films. The prevalence of infection was proportional (P≤0.01) to temperature ...
Kohnen AB, Wiedenheft AM, Traub-Dargatz JL, Short DM, Cook KL, Lantz K, Morningstar-Shaw B, Lawrence JP, House S, Marshall KL, Rao S.Several studies have investigated antimicrobial resistance (AMR) in Salmonella spp. and Escherichia coli isolated from hospitalized horses, but studies conducted on community-based populations of equids are limited. The factors associated with AMR in these bacteria in the general horse population are not well understood. The primary objective of our study was to estimate the prevalence of Salmonella and describe antimicrobial susceptibility of Salmonella and E. coli from equids across the United States. The second objective was to identify associations between health management and biosecurity...
Carrasco L, Sánchez C, Gómez-Villamandos JC, Laviada MD, Bautista MJ, Martínez-Torrecuadrada J, Sánchez-Vizcaíno JM, Sierra MA.African horse sickness (AHS) is a disease of equids, characterized by severe pulmonary oedema and caused by an orbivirus. To determine the role of pulmonary intravascular macrophages (PIMs) in the development of pulmonary microvascular changes in this disease, five horses were given an intravenous inoculation of 10(6)TCID50of serotype 4 of AHS virus. Viral replication was detected in endothelial cells, PIMs, interstitial macrophages and fibroblasts. Alveolar and interstitial oedema, and changes in pulmonary microvasculature, consisting mainly of the sequestration of neutrophils and the formati...
Dagnachew S, Mohammed S, Dessie B, Tilahun M, Ayele A, Kefyalew H.A cross-sectional study was carried out from November 2016 to May 2017 in selected districts of Northwest Ethiopia (Jawi, South Achefer, Dembecha and Jabitehenan) with the aim of determining the prevalence of bovine and equine trypanosomosis, estimating the apparent density of vectors and assessing the effectiveness of control measures of the disease. A total of 1257 animals of which 803 bovine and 454 equine were examined for the determination of prevalence using blood sample collected from ear vein of animals. The buffy coat technique was employed to determine the prevalence and the packed c...
Luciani M, Di Febo T, Orsini M, Krasteva I, Cattaneo A, Podaliri Vulpiani M, Di Pancrazio C, Bachi A, Tittarelli M.The diagnosis of dourine can be difficult because the clinical signs of this disease in horses are similar to those of surra, caused by . Moreover, and are closely related and, so far, they cannot be distinguished using serological tests. In a previous work, the protein pattern recognized by antibodies from dourine-infected horses and the humoral immune response kinetics were investigated by immunoblotting assay; a total of 20 sera from naturally and experimentally infected horses and from healthy animals were tested. Immunoblotting analysis showed that antibodies from infected horses speci...
Monath TP, McLean RG, Cropp CB, Parham GL, Lazuick JS, Calisher CH.Brain tissues were obtained from 5 horses with clinical encephalomyelitis during an epizootic in southwestern Michigan in August-September 1980. These tissues were tested for virus by intracerebral inoculation of suckling mice and by examination of frozen sections and impression smears by the indirect fluorescent antibody (FA) technique. Eastern equine encephalomyelitis virus was isolated and detected by FA technique in brains of 3 horses which died or were euthanatized within approximately 24 hours of onset of the disease but not from 2 horses at 2 and 3 days after onset. The latter 2 animals...
Emmons RW, Woodie JD, Laub RL, Oshiro LS.Main Drain virus, which is thought to be transmitted normally among rabbits and various rodents by its natural vector, Culicoides variipennis, was isolated repeatedly from brain tissue of a sick horse from Sacramento County, California, and was implicated as the causative agent. Signs of illness were incoordination and ataxia, stiff neck, head pressing, inability to swallow, fever, and tachycardia.
McQueen CM, Whitfield-Cargile CM, Konganti K, Blodgett GP, Dindot SV, Cohen ND.Rhodococcus equi (R. equi) is an intracellular bacterium that affects young foals and immuno-compromised individuals causing severe pneumonia. Currently, the genetic mechanisms that confer susceptibility and/or resistance to R. equi are not fully understood. Previously, using a SNP-based genome-wide association study, we identified a region on equine chromosome 26 associated with culture-confirmed clinical pneumonia. To better characterize this region and understand the function of the SNP located within TRPM2 that was associated with R. equi pneumonia, we performed RNA-Seq on 12 horses repres...
Harvey AM, Watson JL, Brault SA, Edman JM, Moore SM, Kass PH, Wilson WD.OBJECTIVE To investigate the impact of age and inferred prior vaccination history on the persistence of vaccine-induced antibody against rabies in horses. DESIGN Serologic response evaluation. ANIMALS 48 horses with an undocumented vaccination history. PROCEDURES Horses were vaccinated against rabies once. Blood samples were collected prior to vaccination, 3 to 7 weeks after vaccination, and at 6-month intervals for 2 to 3 years. Serum rabies virus-neutralizing antibody (RVNA) values were measured. An RVNA value of ≥ 0.5 U/mL was used to define a predicted protective immune response on the b...
Virmani N, Bera BC, Shanumugasundaram K, Singh BK, Gulati BR, Singh RK, Vaid RK.India faced an epizootic of equine influenza in 2008-2009. The isolated viruses were typed as H3N8 and grouped with the clade 2 viruses of Florida sublineage on the basis of haemagglutinin (HA) gene sequence analysis. This report describes the genetic analysis and selection pressure of matrix (M) and non-structural 1 (NS1) genes of the Indian isolates. All isolates shared 98.41% and 99.54% homology with other clade 2 viruses of Asian origin for M1 and M2 amino acid (aa) sequences, respectively. There were 3 and 4 unique aa residue changes respectively in M1 and M2 proteins in all Asian isolate...
Covaleda L, Gno BT, Fuller FJ, Payne SL.The macrophage-tropic lentivirus, equine infectious anemia virus (EIAV), encodes the small auxiliary protein S2 from a short open reading frame that overlaps the amino terminus of env EIAV S2 is dispensable for virus replication in cultured cells but is required for disease production. S2 is approximately 7 kDa and has no overall amino acid sequence homology to other cellular or viral proteins. Therefore it is likely that S2 plays a role as an adaptor protein. To further investigate S2 function we performed a yeast-2-hybrid screen to identify cellular proteins that interact with EIAV S2. The s...
Palmer JE, Whitlock RH, Benson CE, Becht JL, Morris DD, Acland HM.Bacteriologic cultures of 65 rectal mucosal samples and 335 fecal samples from 53 horses and 5 cattle shedding Salmonella were performed. Salmonella spp were isolated from 34 (52%) rectal mucosal samples, 21 (32%) concurrent fecal samples, and 150 (45%) total fecal samples. The use of rectal mucosal samples when compared with concurrently obtained fecal samples significantly (P less than 0.025) improved the ability to isolate Salmonella spp. Concurrent bacteriologic culture of rectal mucosal samples and fecal samples resulted in 39 (60%) isolations. Compared with a series of fecal samples, Sal...
Galan JE, Timoney JF.Purpura hemorrhagica is an acute disease of the horse characterized by edema of the head and limbs, leucocytoclastic vasculitis, petechial hemorrhages in mucosae, musculature and viscera, and sometimes glomerulonephritis. It is usually associated with strangles, an upper respiratory tract disease of the horse caused by Streptococcus equi. We have detected and characterized immune complexes in the sera of horses with poststrangles purpura hemorrhagica by using PEG precipitation and Western blot analysis. The immune complexes contained IgA and S. equi-specific antigens similar to those found in ...
Stone-Marschat M, Carville A, Skowronek A, Laegreid WW.Reverse transcription-PCR (RT-PCR) was used to detect African horse sickness virus (AHSV). A single primer pair which amplified a 423-bp fragment of the S8 gene which encodes the NS2 protein of AHSV was identified. Amplification of this fragment from all nine serotypes of AHSV was achieved with these primers. Between 10(1) and 10(2) copies of AHSV genomic double-stranded RNA could be detected by RT-PCR followed by agarose gel electrophoresis and ethidium bromide staining. Application of RT-PCR to blood samples from AHSV-infected horses resulted in earlier detection of viremia than virus isolat...
Allen LJ, Schwartz EJ.Equine infectious anemia virus (EIAV) is a lentivirus in the retrovirus family that infects horses and ponies. Two strains, referred to as the sensitive strain and the resistant strain, have been isolated from an experimentally-infected pony. The sensitive strain is vulnerable to neutralization by antibodies whereas the resistant strain is neutralization-insensitive. The sensitive strain mutates to the resistant strain. EIAV may infect healthy target cells via free virus or alternatively, directly from an infected target cell through cell-to-cell transfer. The proportion of transmission from f...
Wadsworth AB, Kirkbride MB.Horses immunized to Type I pneumococci developed serum, 0.1 cc. of which protected against 0.5 cc. of a virulent culture, 0.000001 cc. of which killed mice in less than 40 hours. Protective tests of serum from horses immunized to Type II organisms varied, 0.1 cc. protecting, however, in certain instances against 0.1 and 0.01 cc. of virulent homologous culture. Types I and II sera obtained in our experiments with culture sediment and whole culture did not vary markedly for a given type and corresponded closely in their protective titer with samples of sera received from The Rockefeller Institut...
Alvarez I, Gutierrez G, Ostlund E, Barrandeguy M, Trono K.We analyzed the performance of a single-band Western blot (WB) test using recombinant p26 (rp26) capsid protein of equine infectious anemia virus. According to the results obtained, the rp26 WB test is a reliable confirmatory diagnostic tool to be used as a complementary test after an enzyme-linked immunosorbent assay or agar gel immunodiffusion test yielding doubtful results.
Dutta SK, Campbell DL.Equine macrophages from the mammary glands of a yearling filly and an 18-year-old barren nonlactatind mare formed cell monolayers in continuous cultures. There was absence of viral cytopathic effect (CPE) in early cell culture passages. The cells from the early cell culture passages having no CPE failed to show evidence of virus or viral antigen by electron microscopic and immunofluorescence studies. Foci of CPE first appeared in the monolayer cell cultures from the filly and the mare in the 3rd and the 4th serial passages respectively, and the CPE increased on subsequent serial passages. Equi...
Couissinier-Paris P.Until 1999 the West Nile virus had been reported only in the "Old world" and particularly in Europe, Africa, Middle East and Asia where it was responsible only for sporadic or size-and-time-limited outbreaks in humans and equines. The sudden and unexpected emergence of WN in New York in 1999, followed by a rapid and huge extension to the whole North America in less than four years, made health authorities aware of the potential of previously forgotten viruses to become a threat to public health. The present review will focus on the epidemiology of West Nile virus in Europe and Africa during th...
Soilemetzidou ES, de Bruin E, Eschke K, Azab W, Osterrieder N, Czirják GÁ, Buuveibaatar B, Kaczensky P, Koopmans M, Walzer C, Greenwood AD.The majority of influenza A virus strains are hosted in nature by avian species in the orders of Anseriformes and Charadriformes. A minority of strains have been able to cross species boundaries and establish themselves in novel non-avian hosts. Influenza viruses of horses, donkeys, and mules represent such successful events of avian to mammal influenza virus adaptation. Mongolia has over 3 million domestic horses and is home to two wild equids, the Asiatic wild ass or khulan (Equus hemionus hemionus), and Przewalski's horse (Equus ferus przewalskii). Domestic and wild equids are sympatric acr...
Salas Y, Márquez A, Canelón J, Perazzo Y, Colmenárez V, López JA.Pythium insidiosum is a pathogenic oomycete known since 1890 that causes pythiosis in mammals. In this report, seven P. insidiosum isolates were recovered from Venezuelan horses and were characterized. The strains were recovered from biopsied tissues and kunkers collected from granulomatous masses located on the hind limb and from a nodular lesion in the left upper eyelid, which decrease the ability of the horses to be used for working purposes. The methods used to identify P. insidiosum isolates were based on the production of sporangia and zoospores, histopathology and PCR assay. To further ...
Chambers TM, Reedy SE.Serologic tests for equine influenza virus (EIV) antibodies are used for many purposes, including retrospective diagnosis, subtyping of virus isolates, antigenic comparison of different virus strains, and measurement of immune responses to EIV vaccines. The hemagglutination-inhibition (HI), single radial hemolysis (SRH), and serum micro-neutralization tests are the most widely used for these purposes and are described here. The presence of inhibitors of hemagglutination in equine serum complicates interpretation of HI assay results, and there are alternative protocols (receptor-destroying enzy...
Karimi A, Mosavari N.Burkholderia mallei, the etiologic agent of the disease known as glanders. Clinical and bacteriological diagnosis of glanders is difficult in the early stages of the disease. Currently, mallein (allergic hypersensitivity test) is used for the diagnosis of glanders. The mallein test requires an experienced laboratory person and lasts 48 h. Therefore, in order to quickly diagnose the disease, especially in areas (such as the borders of the country) that cannot be kept animals, new methods should be used to identify the disease. The Rose Bengal is a serological diagnostic test and has been recom...
Schuster RK, Sivakumar S, Kinne J, Babiker H, Traversa D, Buzzell GR.Nematode larvae found in histological cuts of lung tissue of a horse from a farm in Al Dhaid (UAE) were determined to belong to the Habronematidae family. The clinical examination of the other 18 horses present in the farm revealed summer sores (cutaneous habronemosis) in two stallions. Nematode larvae were found in 147 (=26.2%) out of 561 male but only in 64 (=8.7%) out of 739 female Musca domestica caught at the farm in November and December 2008. Conversely, all 15 Stomoxys calcitrans specimens caught in the farm resulted negative for nematode larvae. The housefly population caught in the b...
Wu J, Cui Y, Yu F, Muhatai G, Tao D, Zhao A, Ning C, Qi M.Piroplasmosis is a disease that negatively affects equine health worldwide. Hence, 324 blood samples were collected from grazing horses in ten sites in Xinjiang and testing them for the presence of Theileria equi and Babesia caballi by PCR of the EMA-1 gene and BC48 gene, respectively. Of the 324 blood samples, 161 (49.7%) were positive for equine piroplasms. The prevalence of T. equi was 38.9% (126/324), while that of B. caballi was 30.2% (98/324). The T. equi and B. caballi co-infection rate was 19.4% (63/324). From the 126 EMA-1 gene sequences and 98 BC48 gene sequences we obtained, 21 and ...
Collins MT, Cho SN, Reif JS.We examined more than 2,800 human and animal sera for antibodies to four serogroups of Legionella pneumophila by using the microagglutination test. Antibody titers of greater than or equal to 1:64 were considered positive. The occurrence of positive equine sera (31.4%) was significantly higher than the occurrence of positive sera in cattle (5.1%), swine (2.9%), sheep (1.9%), dogs (1.9%), goats (0.5%), wildlife (0%), and humans (0.4%). The highest titer measured in horses was 1:512. The occurrence of positive sera in horses was related directly to age. In horses less than or equal to 1, 2 to 3,...
