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.
Gonzalez-Salazar D, Estrada-Franco JG, Carrara AS, Aronson JF, Weaver SC.To assess the role of horses as amplification hosts during the 1993 and 1996 Mexican Venezuelan equine encephalitis (VEE) epizootics, we subcutaneously infected 10 horses by using four different equine isolates. Most horses showed little or no disease and low or nonexistent viremia. Neurologic disease developed in only 1 horse, and brain histopathologic examination showed meningeal lymphocytic infiltration, perivascular cuffing, and focal encephalitis. Three animals showed mild meningoencephalitis without clinical disease. Viral RNA was detected in the brain of several animals 12-14 days after...
Chaffin MK, Cohen ND, Martens RJ.To identify farm characteristics as risk factors for the development of Rhodococcus equi pneumonia in foals. Methods: Prospective matched case-control study. Methods: 2,764 foals on 64 equine breeding farms with 9,991 horses. Methods: During 1997, participating veterinarians completed paired data collection forms, 1 for a farm with > or = 1 foal with R equi pneumonia and 1 for an unaffected control farm. Matched data were compared by use of conditional logistic regression analysis. Results: Farm characteristics found in bivariate analyses to be associated with increased risk for pneumonia caus...
Lee JS, Hadjipanayis AG, Welkos SL.Anthrax, a disease usually associated with herbivores, is caused by the bacterium Bacillus anthracis. The current vaccine licensed for human use requires a six-dose primary series and yearly boosters and causes reactogenicity in up to 30% of vaccine recipients. A minimally reactogenic vaccine requiring fewer inoculations is warranted. Venezuelan equine encephalitis (VEE) virus has been configured for use as a vaccine vector for a wide variety of immunogens. The VEE vaccine vector is composed of a self-replicating RNA (replicon) containing all of the VEE virus nonstructural genes and a multiple...
Marti E, Horohov DW, Antzak DF, Lazary S, Paul Lunn D.The horse has been human kind's most important partner throughout history. Similarly, in the field of immunology, many critical scientific advances have depended on the horse. Equine immunology today is an active and important field of study, with a focus on control of many common infectious diseases and immunopathologic conditions of broad comparative interest. In 2001 two major equine immunology workshops were held, in Santa Fe, USA, and in Hortobagy, Hungary, with major sponsorship from the Havemeyer Foundation. This report summarizes the scientific themes and foci of those meetings.
Patterson-Kane JC, Caplazi P, Rurangirwa F, Tramontin RR, Wolfsdorf K.Encephalitozoon cuniculi is a microsporidial parasite, which has rarely been reported to cause placentitis in animals. A late-term aborted fetus and placenta from a Quarterhorse were presented to the Livestock Disease Diagnostic Center, University of Kentucky, for diagnostic examination. There was a necrotizing placentitis, with distension of many chorionic epithelial cells by intracytoplasmic vacuoles containing 1-2-microm-diameter, elongated, gram-positive organisms. The organisms were identified as E. cuniculi by electron microscopy and by polymerase chain reaction using primers to microspo...
Duarte PC, Daft BM, Conrad PA, Packham AE, Gardner IA.A serum indirect fluorescent antibody test (IFAT) was compared with a Western blot (WB) and a modified Western blot (mWB) for diagnosis of equine protozoal myeloencephalitis (EPM). Using receiver-operating characteristic (ROC) analysis, the area under the curve of the IFAT was greater than the areaunder the curves of the WB and the mWB (P = 0.025 and P = 0.044, respectively). There was no statistically significant difference between the areas under the curves of the WBs (P > 0.05). On the basis of an arbitrarily chosen cut-off titer for a positive test result of 1:80 for the IFAT and interpret...
Research in microbiologyFebruary 11, 2003
Volume 154, Issue 1 29-35 doi: 10.1016/s0923-2508(02)00003-7
Silva TA, Rodrigues PH, Ribeiro RN, Noronha FS, Farias Lde M, Carvalho MA.The influence of growth medium, hemin and menadione, blood source and atmosphere of incubation on the expression of hemolytic activity of 25 strains of Prevotella intermedia and Prevotella nigrescens was evaluated. The best hemolytic activity was observed for samples of both species growing in brain heart infusion agar and incubated in Brewer-like anaerobic jars for 48 h. Hemolysis was less intense and occurred later in the presence of hemin and menadione in solid media. beta-Hemolysis was detected for medium supplemented with horse or human blood and alpha-hemolysis was observed when sheep bl...
Crespo MJ, Abarca ML, Cabañes FJ.During a study on the occurrence of Malassezia spp. in 112 animals (50 horses, 25 goats, 25 sheep and 12 cows), Malassezia spp. were isolated from 60% of horses, 28% of sheep, 44% of goats and 58% of cows. In these animals, the occurrence of lipid-dependent species (42%) was much greater than the occurrence observed for M. pachydermatis (3%). Among the results obtained, we point out the first isolation of M. sympodialis, M. globosa and M. restricta from sheep, M. pachydermatis, M. furfur, M. sympodialis, M. obtusa, M. globosa and M. restricta from goats and M. furfur, M. slooffiae, M. obtusa, ...
Hirata H, Xuan X, Yokoyama N, Nishikawa Y, Fujisaki K, Suzuki N, Igarashi I.The efficacy of the Be82 gene product fused with glutathione S-transferase (GST/Be82) in an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Babesia equi infection was reported previously (H. Hirata et al., J. Clin. Microbiol. 40:1470-1474, 2002). However, the ELISA with the GST/Be82 antigen cross-reacted with Babesia caballi-infected horse sera, despite the high rate of detection of B. equi. These results suggested that GST/Be82 has an antigen in common with B. caballi or antigenicity similar to that of B. caballi. In the present study, we constructed a series of five clones wit...
Rappocciolo G, Birch J, Ellis SA.There is good evidence that cytotoxic T lymphocytes play an important role in the clearance of equine herpesvirus-1 (EHV1) in horses. We have demonstrated that, in common with other alphaherpesviruses, EHV1 infection can lead to dramatic down-regulation of MHC class I expression at the cell surface, a common strategy for pathogen evasion of the host immune response. This down-regulation is specific for MHC class I and does not reflect a general shut-off of host-cell protein synthesis. The use of monoclonal antibodies that recognize different MHC class I epitopes has demonstrated that the effec...
Cohen ND, Donahue JG, Carey VJ, Seahorn JL, Piercy D, Donahoe JK, Williams DM, Brown SE, Riddle TW.To identify factors associated with abortions during early gestation classified as mare reproductive loss syndrome (MRLS). Methods: Case-control study. Methods: 324 broodmares from 43 farms in central Kentucky, including 121 mares from 25 farms that had early-term abortions (ETAs) associated with MRLS (case horses), 120 mares from the same farms but that did not abort, and 83 mares from 18 farms that were not severely Impacted by MRLS. Methods: Farm managers were interviewed to obtain data on various management practices and environmental exposures for the mares. Data for case and control hors...
Akiba M, Uchida I, Nishimori K, Tanaka K, Anzai T, Kuwamoto Y, Wada R, Ohya T, Ito H.Equine paratyphoid is caused by Salmonella enterica serovar Abortusequi, and manifests mainly as abortion in the mare. We compared S. Abortusequi strains isolated in Japan and other countries using pulsed-field gel electrophoresis (PFGE) and fluorescent amplified-fragment length polymorphism (FAFLP) analysis. PFGE analysis of S. Abortusequi strains gave 21-27 fragments ranging in size from 33 to 602kb. Although two PFGE profiles were observed among the 20 S. Abortusequi isolates in Japan, the restriction fragments originating from the chromosome were common between the two profiles. The simila...
Peek SF, Semrad SD, Perkins GA.Previous reports of clostridial myonecrosis have either focused on individual case reports or have been small retrospective studies reporting very high mortality rates. Objective: The objective of this study was to describe the outcome of cases of clostridial myonecrosis submitted to 2 referral equine hospitals in the United States over a 15 year period. Methods: A retrospective study of case material selected on the basis of positive Clostridium spp. culture or the identification of Clostridium spp. by specific fluorescent antibody testing from soft tissue wounds was performed at Cornell and ...
Mumford EL, Traub-Dargatz JL, Carman J, Callan RJ, Collins JK, Goltz KL, Romm SR, Tarr SF, Salman MD.Horses vaccinated against common agents of infectious upper respiratory disease (IURD) may not have detectable serum antibody and may not be protected from clinical disease. Objective: The objectives of this study were to 1) investigate the serological response of horses to vaccination against influenza virus (H3N8 and H7N7) and equine herpesviruses (EHV) in a field setting and 2) evaluate associations among vaccination status, serum antibody concentrations, and occurrences of IURD in monitored horses. Methods: In this study, horses on 6 Colorado premises were vaccinated parenterally against i...
Dagleish MP, Brazil TJ, Scudamore CL.Lipopolysaccharide (LPS) and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-like peptides are Gram-negative bacterial cell wall components which, when released into the peripheral circulation in endotoxaemia, have the potential to activate leucocytes. In vitro, equine neutrophils require priming with LPS in order to generate reactive oxygen intermediates (ROI) in response to fMLP. Objective: The aim of this study was to examine whether the release of other neutrophil products is similarly dependent on prior priming with LPS. In particular, neutrophil elastase (NE), a potent proteolytic enzyme,...
Maury W, Wright PJ, Bradley S.A novel strain of equine infectious anemia virus (EIAV) called vMA-1c that rapidly and specifically killed infected equine fibroblasts (ED cells) but not other infectible cell lines was established. This strain was generated from an avirulent, noncytopathic strain of EIAV, MA-1. Studies with this new cytolytic strain of virus have permitted us to define viral parameters associated with EIAV-induced cell killing and begin to explore the mechanism. vMA-1c infection resulted in induction of rapid cell death, enhanced fusogenic activity, and increased rates of spread in equine fibroblasts compared...
Rossano MG, Kaneene JB, Marteniuk JV, Banks BD, Schott HC, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a neurological disease of horses and ponies caused by infection of the central nervous system with the protozoan parasite Sarcocystis neurona. A herd-level analysis of a cross-sectional study of serum antibodies to S. neurona in Michigan equids was conducted, using data collected in 1997 for study that included 1121 equids from 98 Michigan horse farms. Our objective was to identify specific herd-level risk factors associated with seropositivity. We tested associations between herd seroprevalence and various farm-management practices (including feed-s...
The Journal of parasitologyJanuary 23, 2003
Volume 88, Issue 6 1239-1246 doi: 10.1645/0022-3395(2002)088[1239:QEOSTF]2.0.CO;2
Packham AE, Conrad PA, Wilson WD, Jeanes LV, Sverlow KW, Gardner IA, Daft BM, Marsh AE, Blagburn BL, Ferraro GL, Barr BC.Neospora hughesi is a newly recognized protozoan pathogen in horses that causes a myeloencephalitis similar to Sarcocystis neurona. There are no validated serologic tests using the gold standard sera that are currently available to detect specific N. hughesi antibodies and, thus, no tests available to detect antemortem exposure or estimate seroprevalence in the horse. The objectives of the present study were to establish a bank of gold standard equine sera through experimental infections with N. hughesi and to assess several serologic tests for the detection of related protozoan antibodies. Se...
The Journal of parasitologyJanuary 23, 2003
Volume 88, Issue 6 1252-1254 doi: 10.1645/0022-3395(2002)088[1252:EOHTAD]2.0.CO;2
Dubey JP, Saville WJ, Sreekumar C, Shen SK, Lindsay OS, Pena HF, Vianna MC, Gennari SM, Reed SM.The effect of moist heat and several disinfectants on Sarcocystis neurona sporocysts was investigated. Sporocysts (4 million) were suspended in water and heated to 50, 55, 60, 65, and 70 C for various times and were then bioassayed in interferon gamma gene knockout (KO) mice. Sporocysts heated to 50 C for 60 min and 55 C for 5 min were infective to KO mice, whereas sporocysts heated to 55 C for 15 min and 60 C or more for 1 min were rendered noninfective to mice. Treatment with bleach (10, 20, and 100%), 2% chlorhexidine, 1% betadine, 5% o-benzyl-p-chlorophenol, 12.56% phenol, 6% benzyl ammoni...
van der Meulen KM, Nauwynck HJ, Pensaert MB.Equine herpesvirus-1 (EHV-1) may cause abortion in vaccination- and infection-immune horses. EHV-1-infected peripheral blood mononuclear cells (PBMCs) play an important role in virus immune evasion. The mechanisms by which infected PBMCs can avoid destruction by EHV-1-specific antibody and equine complement were examined. The majority of EHV-1-infected PBMCs (68.6 %) lacked surface expression of viral antigens and these cells were not susceptible to complement-mediated lysis. In infected PBMCs with surface expression of viral antigens, 63 % showed focal surface expression, whereas 37 % showed ...
Ridgely SL, Zhang B, McGuire TC.Lipopeptide containing an ELA-A1-restricted cytotoxic T lymphocyte (CTL) epitope from the envelope surface unit (SU) protein of the EIAV(WSU5) strain was used to immunize three horses having the ELA-A1 haplotype. Peptide-specific ELA-A1-restricted CTL were induced in all three horses, although these were present transiently in PBMC. These horses were further immunized with lipopeptide containing the corresponding CTL epitope from the EIAV(PV) strain. Then, the three immunized horses and three non-immunized horses were challenged by intravenous inoculation with 300 TCID(50) EIAV(PV). All horses...
Pitel PH, Lindsay DS, Caure S, Romand S, Pronost S, Gargala G, Mitchell SM, Hary C, Thulliez P, Fortier G, Ballet JJ.Sarcocystis neurona is considered a leading cause of equine protozoal myeloencephalitis (EPM), a common infectious neurological disease in horses in the Americas. EPM-like cases associated with S. neurona peptide reactive antibodies in Western blots were recently described in Normandy, France. In this report, antibodies reacting with S. neurona merozoites were detected using an agglutination assay at titers ranging from 50 to 500 in sera from 18/50 healthy horses from two farms with a previous EPM-like case. Higher values were found in older animals. Four out of six horses which traveled or st...
Monzon CM, Mancebo OA, Russo AM.An ELISA test was used to determine the persistence of antibody levels in horses following treatment for Trypanosoma evansi. In 17 horses with T. evansi from two farms treated and cured with quinapyramine sulphate, ELISA antibody levels fell progressively post-treatment, but remained with positive results for 22.6 months in one horse, 12.8 months in a second, 4.1 months in another four and 2.3 months in three, whilst the rest became negative at 2.3 months. In two horses that suffered a post-treatment infection relapse the decrease in ELISA levels was only temporary, and a new increase in antib...
Fermaglich DH, Horohov DW.Although vaccine manufacturers make no specific recommendations regarding the vaccination of older horses and ponies, the similarities in age-induced immunologic changes between human beings and equids suggests that similar vaccination recommendations should be followed. The need for vaccination of the older horse depends, of course, on the relative risk of exposure for the individual horse. Particular care should be taken when using attenuated vaccine products because these live agents may pose a unique risk to the older individual. Immunization with inactivated agent vaccines is likely to be...
Venter GJ, Groenewald D, Venter E, Hermanides KG, Howell PG.Equine encephalosis virus (EEV) is widespread and prevalent in southern Africa. In this study, the oral susceptibility of Culicoides (Avaritia) imicola Kieffer (Diptera: Ceratopogonidae) to EEV was confirmed. In addition, C. (A.) bolitinos Meiswinkel, collected in the high-lying eastern Free State, South Africa, was systemically infected with the Bryanston serotype of EEV after feeding through a membrane on artificially infected equine blood containing 4.7 log10 PFU/mL of EEV. The mean infectivity of Bryanston virus in C. bolitinos increased from 1.2 log10 PFU/midge, in midges assayed for viru...
Donahue JM, Williams NM, Sells SF, Labeda DP.Over the course of the past decade, actinomycetes have been isolated from the placentas of horses diagnosed with nocardioform placentitis. The incidence of this infection has generally been low, with typically no more than 30 animals affected in most years, but the incidence increased through 1999, with placentas from 144 mares found to be infected. Approximately half of the cases result in loss of the foal. A typical actinomycete with branching mycelium was isolated from placental lesions, and a comparison of the sequence of the 16S rDNA gene against the public databases indicated a relations...
Faverjon C, Leblond A, Lecollinet S, Bødker R, de Koeijer AA, Fischer EAJ.African horse sickness (AHS) and equine encephalosis (EE) are Culicoides-borne viral diseases that could have the potential to spread across Europe if introduced, thus being potential threats for the European equine industry. Both share similar epidemiology, transmission patterns and geographical distribution. Using stochastic spatiotemporal models of virus entry, we assessed and compared the probabilities of both viruses entering France via two pathways: importation of live-infected animals or importation of infected vectors. Analyses were performed for three consecutive years (2010-2012). Se...
Faber E, Tshilwane SI, Kleef MV, Pretorius A.African horse sickness (AHS) is caused by African horse sickness virus (AHSV), a double stranded RNA (dsRNA) virus of the genus Orbivirus, family Reoviridae. For the development of new generation AHS vaccines or antiviral treatments, it is crucial to understand the host immune response against the virus and the immune evasion strategies the virus employs. To achieve this, the current study used transcriptome analysis of RNA sequences to characterize and compare the innate immune responses activated during the attenuated AHSV serotype 4 (attAHSV4) (in vivo) and the virulent AHSV4 (virAHSV4) (in...
Nemoto M, Yamayoshi S, Bannai H, Tsujimura K, Kokado H, Kawaoka Y, Yamanaka T.Equine influenza virus is an important pathogen for the horse industry because of its economic impact, and vaccination is a key control measure. Our previous work suggested that a mutation at position 144 in the hemagglutinin of Florida sublineage clade 2 viruses reduces the cross-neutralizing activity of antiserum against a former vaccine strain. To confirm this suggestion, here, we generated viruses by reverse genetics. Antibody titers against the mutated viruses were one-tenth to one-sixteenth of those against the former vaccine strain. Our findings confirm that this single amino acid subst...
Rubio C, Cubillo MA, Hooghuis H, Sanchez-Vizcaino JM, Diaz-Laviada M, Plateau E, Zientara S, Crucière C, Hamblin C.The mortality rate in susceptible populations of horses during an epizootic of African horse sickness (AHS) may be in excess of 90%. Rapid and reliable assays are therefore essential for the confirmation of clinical diagnoses and to enable control strategies to be implemented without undue delay. One of the major objectives of a recent European Union funded project was the validation of newly developed diagnostic assays which are rapid, sensitive, highly reproducible and inexpensive, for the detection of African horse sickness virus (AHSV) antigens and antibodies. The Laboratorio de Sanidad y ...
Debarbat F, Mollaret HH, Mailloux M.Bovine leptospirosis is a typical form in the island of Reunion. It appears during the second part of the rain season. The clinical picture of equine leptospirosis is acute hepatonephritis. About 10 serogroups are found in bovines, with greater frequency for Sejroë and Hebdomadis. In horses, the prevailing serogroups are Autumnalis, Ballum, Icterohaemorrhagiae, Australis, Grippotyphosa.
Anzai T, Kamada M, Niwa H, Eguchi M, Nishi H.Contagious equine metritis (CEM), a contagious venereal disease of horses, invaded Japan in 1980 and spread in the Thoroughbred population of the Hidaka-Iburi district of Hokkaido. To eradicate CEM, we ran a program aimed at detecting Taylorella equigenitalis, the causal agent, in carrier horses by using the PCR test, followed by culling or treatment. In 2001, the first year of the program, 12,356 Thoroughbred racing stallions and mares were tested and 11 carriers were found. Four, two, one, and one carrier mares were detected in 2002, 2003, 2004, and 2005, respectively, by application of the ...
Maeda K, Kai K, Matsumura T.Infection with equine herpesvirus-4 (EHV-4) is a major cause of respiratory tract disease, equine rhinopneumonitis, in horses. Although the full sequence of EHV-4 has been reported, genomic differences among EHV-4 field isolates have not yet been characterized. In this study, the genomic diversity between 23 Japanese EHV-4 isolates was analyzed by digestion with restriction endonucleases (BamHI, BgIII, EcoRI, SacI, and SalI) and polymerase chain reaction (PCR). The restriction endonuclease digestion patterns of the EHV-4 field isolates showed distinct differences which included mobility shifts...
Asenzo G, Wilkowsky S, Barrandeguy M, Mesplet M, Benitez D, Florin-Christensen M.An indirect ELISA (iELISA) for the detection of specific anti-Theileria equi antibodies in horse serum was developed. Its performance showed good concordance (K= 0.79) when compared with a competitive ELISA recommended by the World Organisation for Animal Health. Horse serum samples from two provinces located in the north and east of Argentina (Formosa and Entre Rios, respectively) were analyzed by this iELISA. A high percentage of positive horses were found in Formosa, consistent with the climatic conditions of the region that are apt for the development of tick vectors. Surprisingly, seropos...
Beck A, Baird JD, Slavić D.This is the first report of the isolation of Actinomyces denticolens, an opportunistic pathogen, from a draining submandibular lymph node abscess in a horse in Ontario. Due to the similarity of the clinical signs with strangles, this pathogen should be included in the differential diagnosis of submandibular lymphadenopathy in the horse. Il s’agit du premier rapport d’isolement d’ un agent pathogène opportuniste, lors du drainage d’un abcès d’un ganglion lymphatique sous-maxillaire chez un cheval en Ontario. En raison de la similarité des signes cliniques avec ceux de la gourme, ...
Kirchhoff H, Heitmann J, Bisping W.Mycoplasmas were isolated from 11 (=#6,8%) of 161 cervix swabs from infertile mares. A total of 17 strains was isolated and characterized by indirect immunofluorescent test and metabolic inhibition test as Mycoplasma equigenitalium (11 strains), Mycoplasma subdolum (2 strains), Acholeplasma laidlawii (3 strains) and Acholeplasma equifetale (1 strain). In addition cervix swabs of the mares were investigated for bacteria. There was no specific correlation between presence of mycoplasmas and bacteria (table 1). In clinical investigations 5 of the 11 mares which harboured mycoplasmas showed a pneu...
Maloufi F.From March to September 1991, horses (n = 1567), donkeys (n = 112) and mules (n = 96) were examined for equine parafilariosis by random sampling from different areas of Iran. The clinical signs of equine parafilariosis were observed in 136 cases of two northern areas (1.4% and 41.3% infection rate) and one northeastern area (6.3% infection rate). Most of the infected cases were confirmed by laboratory findings. All infected cases were followed up to establish the epidemiological features. The results suggest that there is one enzootic area in Iran, the Caspian coast and Persian Turkman steppes...
Floyd K, Suter PF, Lutz H.Direct staining of the granules of blood eosinophils by anti-immunoglobulin fluorescein isothiocyanate (FITC) conjugates was observed when feline blood smears were tested for presence of feline leukemia virus (FeLV) antigen by immunofluorescent antibody. When blood smears of other species including swine, horses, cattle, dogs, sheep, birds, and human beings were examined, direct staining of eosinophils by FITC conjugates was also detected. This FITC staining was restricted to eosinophils and was not observed in neutrophils, lymphocytes, and platelets. Direct FITC staining of eosinophils does n...
Gummow B, de Wet CS, de Waal DT.Serum samples from yearling Thoroughbred horses (n = 176) in the magisterial districts of Colesberg, Venterstad, and Wodehouse in the Northern and Eastern Cape Provinces were collected between September and November 1995 to determine the prevalence of antibodies to Babesia equi and Babesia caballi in these regions. Samples were examined for specific antibodies using the indirect fluorescent antibody test. The 95% confidence intervals for the prevalence of serum antibodies in the 3 districts combined varied from 47% to 61% for B. equi and from 26% to 40% for B. caballi. Antibody prevalence did ...
McChesney SL, England JJ, McChesney AE.An agent lethal to embryonated chicken eggs was isolated from lung tissues of a quarter horse mare with a fatal respiratory disease. The lesions induced in embryonated chicken eggs, the tinctoral properties, the ultrastructural morphology, the resistance of the organism to sodium sulfadiazine, and the presence of a chlamydial complement fixing antigen, identify this isolate as a member of the family Chlamydiaceae and suggest the agent to be Chlamydia psittaci. Two Shetland ponies experimentally infected with the isolated agent developed subclinical infection as demonstrated by an increase in c...
Rockx B, Mire CE.Henipaviruses are emerging zoonotic viruses that can cause outbreaks of severe respiratory and neurological disease in humans and animals such as horses. The mechanism by which these viruses can cause disease remain largely unknown and to date there are no therapeutics or vaccines approved for use in humans. Nipah virus is listed on the World Health Organization R & D Blueprint list of epidemic threats. In order to advance the availability of effective therapeutics and vaccines and medicines that can be used to save lives and avert large scale crises, animal models are required which recap...
Zhu C, Li Q, Guo W, Lu G, Yin X, Qi T, Xiang W, Ran D, Qu J.We report the complete genomic sequence of A/equine/Heilongjiang/1/2010, a strain of Florida sublineage clade 2 of H3N8 subtype equine influenza virus (EIV) isolated in northern China. This is the first announcement of a complete genomic sequence of EIV of such a clade in China.
Takai S, Yoda A, Sasaki Y, Kakuda T, Suzuki Y, Oikawa M.Tracheal washing fluid was collected from 170 foals at 28 and 35 d old from February to July in a foaling season on horse-breeding farms with sporadic rhodococcosis in Japan and was investigated by quantitative culture. The history of the 170 foals followed up for the next few months. The proportion of R. equi-positive foals at 28 and 35 d old was significantly increased according to the birth month. Furthermore, the mean number of R. equi in the tracheal washing fluid of each month group increased according to their birth month with the rise in outside temperature. During the follow-up observ...
Barrell EA.Polyuria and polydipsia are rare, but significant, manifestations of several different diseases of horses. Causes can be endocrine, iatrogenic, psychogenic, infectious, or toxic in nature and can also be due to primary renal disease or diseases of other organs, such as the liver. Although numerous causes of polyuria and polydipsia in horses exist, the most common conditions include chronic kidney disease, pituitary pars intermedia dysfunction, and psychogenic polydipsia with secondary polyuria. Additional testing is dictated by history, other clinical signs, and the results of blood work and/o...
Walter J, Seeh C, Fey K, Bleul U, Osterrieder N.Equine herpesvirus myeloencephalopathy (EHM) is a severe manifestation of equine herpesvirus 1 (EHV-1) infection. Prevention and treatment of EHM during EHV-1 outbreaks is critical, but no reliable and tested specific medication is available. Due to the thromboischemic nature of EHM and due to the fact that EHV-1 entry in cells is blocked by heparin, it was hypothesized that this compound may be useful in reduction of EHM incidence and severity. Therefore, during an acute EHV-1 outbreak with the neuropathogenic G/D Pol variant, metaphylactic treatment with heparin to prevent EHM was initiated....
Tu YB, Zhou T, Yuan XF, Qiu HJ, Xue F, Sun CQ, Wang L, Wu DL, Peng JM, Kong XG, Tong GZ.The long terminal repeats (LTRs) of equine infectious anemia virus donkey leukocyte-attenuated virus (EIAV-DLA) were substituted with those of the wild-type EIAV-L (wt EIAV-L, the parent virus of EIAV-DLA). The resulting chimeric plasmid was designated pOK-LTR DLA/L. Purified pOK-LTR DLA/L was transfected into monocyte-derived macrophage (MDM) cultures prepared from EIAV-negative, heparinized whole blood from a donkey. Eighth-passage cell cultures developed the typical cytopathogenic effects (CPE) of EIAV infection, and virions with typical EIAV profiles were observed with an electron microsco...
Pellegrini-Masini A, Dolente BA, Habecker PL, Jesty SA.A 5-year-old Quarter Horse mare was referred for evaluation of oral ulcers, limb edema, weight loss, and weakness. There was marked diffuse swelling extending from the stifle region to the tarsal region of the left hind limb, and the horse had a left hind limb lameness. Firm swellings ranging from 2 to 15 cm in diameter and consisting of nodules, plaques, and discrete masses were palpated on both sides of the neck, over the right shoulder region, over the left elbow region, and over the left caudoventral aspect of the abdomen. Laboratory abnormalities included hypoproteinemia, neutrophilia, an...
De Cock HE, Labelle P, Magdesian KG.The clinical, gross morphological, histological and immunohistochemical characteristics of an ameloblastic carcinoma in a 30-year-old Quarter Horse mare are reported. This tumour was fast growing, locally invasive and destructive. Histologically, it showed an infiltrative pattern of large islands, broad sheets and, at the periphery, small cords of moderately pleomorphic round, oval to spindle-shaped cells. Immunohistochemical evaluation revealed positive labelling for vimentin, cytokeratin 5/6 and cytokeratin 14. In the oral cavity of human beings, this immunolabelling pattern is unique for th...
Kirchhoff H, Ammar AM, Heitmann J, Dubenkropp H, Schmidt R.Sera from horses with respiratory disease (RD) have been investigated using the complement fixation test, indirect hemagglutination test, enzyme immune assay, and the metabolic inhibition test, and sera from mares after abortion, using the complement fixation test, indirect hemagglutination test and enzyme immune assay, for antibodies against Mycoplasma equirhinis, M subdolum, M. equigenitalium, M. pulmonis, M. felis, Acholeplasma laidlawii, A. hippikon and A. equifetale. Antibodies were found against all mycoplasma and acholeplasma species tested, more often against acholeplasmas. The antibod...
Songsri J, Mala W, Wisessombat S, Siritham K, Cheha S, Noisa N, Wongtawan T, Klangbud WK. O157:H7 is enterohemorrhagic , which produces verocytotoxin or Shiga toxin. It is a well-known cause of severe diseases in humans worldwide. Cattle and other ruminants are the main reservoirs of this organism. Sports animals, such as fighting bulls, riding horses, and fighting cocks, are economic animals in Southern Thailand. This study aimed to identify O157:H7 from the rectal swabs of these sports animals and determine the antimicrobial susceptibility patterns of isolated bacteria. Unassigned: The rectal swabs were collected from 34 fighting bulls, 32 riding horses, and 31 fighting cocks. ...
Yamanaka T, Tsujimura K, Kondo T, Hobo S, Matsumura T.We investigated the efficacy of the oral administration of oseltamivir phosphate (OP) in horses experimentally infected with equine influenza A virus (H3N8). Nine horses were divided into three horses each of control, treatment and prophylaxis groups. An administration protocol for the treatment group (2 mg/kg of body weight, twice a day for five days) was started immediately after the onset of pyrexia (above 38.9 degrees C). An administration protocol for the prophylaxis group (2 mg/kg of body weight, once a day for five days) was started on a day before viral inoculation. In the treatment gr...
Sahu SP, Dardiri AH.Uterine, cervical, and clitoral specimens on swabs from pony mares infected with contagious equine equine metritis (CEM) bacteria were streaked on agar plates. Colonies of CEM bacteria were observed under CO2 incubation in 2 days on Eugon chocolate agar and Eugon blood agar plates. The diameter of the colonies varied from 0.2 mm to 1 mm in 2 days which increased to 0.3 mm to 2.0 mm on day 4. The colonies on Eugon chocolate agar plates on days 2 to 4 were shiny, brown, round, and convex, and easily glided when pushed with a loop. The diameter of the colonies on chocolate and blood agar plates m...
Williams R, Du Plessis DH, Van Wyngaardt W.Group-reactive enzyme-linked immunosorbent assays (ELISAs) were developed to selectively detect antibodies to African horsesickness virus (AHSV) and equine encephalosis virus (EEV), 2 orbiviruses that infect equids. In indirect ELISA, guinea pig antisera to all known AHSV or EEV serotypes recognized immobilized AHSV serotype 3 or EEV Cascara, respectively. Antisera from naturally infected animals did not cross-react with their respective heterologous viruses. The ELISA was used in parallel with the complement fixation (CF) and agar gel immunodiffusion tests to detect antibodies in sera from an...
Dwyer RM.Rotavirus poses a challenge each foaling season to farm managers and veterinarians in intensive horse breeding areas throughout the world. By understanding the epidemiology of the disease as well as characteristics of the virus, veterinarians can make sound recommendations on prevention and control of outbreaks. Even when effective prophylactic products are developed, farm management practices, including quarantine, disinfection, and hygiene, will always need to be in force to prevent any contagious disease outbreak.
Wang T, Magnarelli LA, Anderson JF, Gould LH, Bushmich SL, Wong SJ, Fikrig E.Recombinant West Nile virus envelope (E) protein was examined in enzyme-linked immunosorbent assay (ELISA) to detect antibodies elicited during West Nile virus infection. Horses (nine of 10) and humans (six of six) with confirmed West Nile virus infection had IgG and/or IgM antibodies to the E protein. Antibodies to the recombinant West Nile virus membrane and nonstructural 1 proteins were not detected in any of these sera. An E protein-based ELISA may aid in the serological diagnosis of West Nile virus infection.
Kumanomido T, Kamada M, Wada R, Kenemaru T, Sugiura T, Akiyama Y.Sagiyama virus is a member of the Getah virus group. Its pathogenicity for horses was examined. All the horses infected with the original 4 strains of Sagiyama virus (M6/Mag 33, Mag 121, Mag 132 and Mag 258) developed pyrexia ranging from 39.0 to 40.0 degrees C. Other clinical signs, characterized by eruptions, edema in the hind legs, enlargement of the submandibular lymph node and mild leukopenia, were also manifested. Viremia occurred 1-4 days post-inoculation (p.i.). Virus was recovered from spleen, liver, lung and various lymph nodes of a horse autopsied on Day 4 p.i. The maximum titer of ...
