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.
Perkins NR, Webster WR, Wright T, Denney I, Links I.At the time of the initial notification of the occurrence of equine influenza (EI) in Australia in August 2007, vaccination was restricted to horses for which it was an import requirement and only with the approval of the state or territory Chief Veterinary Officer. This paper describes the complexities involved in the selection of a vaccine and its distribution. A combination of ring, predictive and blanket vaccination was implemented during the response. The specific vaccination programs, including its use in buffer zones and for movement of horses, the performance of the vaccine, any advers...
Smyth GB, Dagley K, Tainsh J.We estimate and describe the financial costs of the equine influenza (EI) outbreak in Australia, including the costs of emergency response measures and lost income/assets to businesses, associations and private horse owners. Costs to associations, governments and industry are discussed. We identify a lack of reliable data about the financial costs of the EI outbreak to the non-racing sectors of the horse industry.
Bell IG, Drury-Klein C.To analyse horse event and horse movement registration data collected between September 2007 and December 2008 during the outbreak of equine influenza in New South Wales, Australia. Results: A total of 9356 events were registered, involving 504,382 horses and 242,952 riders. Registered horse movements totalled 224,084, involving 349,327 horses (excluding mobs) travelling 34.4 million km with an average of 154 km per journey. The number of recorded events and movements were low while movement controls were most stringent, then increased from December 2007 as restrictions were eased, to peak in ...
Kirkland PD.During the 2007 equine influenza (EI) outbreak in Australia, diagnostic laboratories and the use of appropriate tests played a pivotal role in the response to the crisis. This role began with the detection of EI virus in New South Wales (NSW) on the evening of 24 August 2007 and culminated in providing the final 'proof of freedom' from EI in March 2008. The tests that were used during the EI response were able to provide results quickly, and with high sensitivity and specificity. This section of the supplement describes the roles and functions of the Australian laboratories; tests used and the...
Dhand NK, Sergeant ES.The aim of this preliminary study was to estimate the proportions of seropositive horses on infected premises (IPs) in order to assess the attack risk of the disease. Logistic regression analyses were conducted to evaluate the differences in attack risks between enterprise sizes and predefined spatial clusters/regions. The average attack risk experienced during the outbreak was 96.88% (median 100%), but it differed according to the size of the enterprise and other geographic and demographic conditions. The highest attack risks were observed in the Dubbo cluster/region and the lowest in the Nar...
Oakey J, Hawkesford T, Smith C, Hewitson G, Tolosa X, Wright L, Moody N, Rodwell B, Corney B, Waltisbuhl D.Describe the in-house validation of a previously reported influenza virus type A 5'Taq nuclease assay for detecting equine influenza virus A RNA in nasal swab material. Methods: The validation compares the 5'Taq nuclease assay with a gel-based reverse transcription nested polymerase chain reaction (PCR) previously reported by the Irish Equine Centre for detection of H3N8 and H7N7 equine influenza viruses. This test was chosen because it targets a different region of the viral genome to the real-time test, so it is not merely a repeat of the same test in a different format. Moreover, nested PCR...
Brown L, Townsend W, Waltisbuhl D.The unique challenges that laboratories in Queensland and New South Wales faced during the response to the 2007 equine influenza outbreak and how these were managed are described.
Crispe E, Finlaison DS, Hurt AC, Kirkland PD.During the equine influenza (EI) outbreak, respiratory disease was observed in dogs that were in close proximity to infected horses. Investigations were undertaken to exclude influenza virus infection. Of the 23 dogs that were seropositive in tests using the influenza A/Sydney/2007 virus as the test antigen, 10 showed clinical signs. EI virus appeared to be readily transmitted to dogs that were held in close proximity to infected horses, but there was no evidence of lateral transmission of the virus to other dogs that did not have contact with or were not held in close proximity to horses.
Croft MG, Fraser GC, Gaul WN.A Laboratory Information Management System (LIMS) was used to manage the laboratory data and support planning and field activities as part of the response to the equine influenza outbreak in Australia in 2007. The database structure of the LIMS and the system configurations that were made to best handle the laboratory implications of the disease response are discussed. The operational aspects of the LIMS and the related procedures used at the laboratory to process the increased sample throughput are reviewed, as is the interaction of the LIMS with other corporate systems used in the management...
Webster WR.In August 2007 equine influenza (EI) was diagnosed in Australia's horse population following the failure to contain infection in quarantine after the importation of one or more infected horses. The response had many unique features, and addressed financial, social, economic, human and animal health, trade and recovery issues. The outbreak and the associated control measures had a vast impact on individual horse owners, the horse industry and associated sectors in both infected and uninfected states.
Morton JM, Dups JN, Anthony ND, Dwyer JF.The risk of individuals becoming infected during an epidemic of infectious disease can vary as the disease progresses. Monitoring this risk may provide information about the dynamics of transmission. This study describes the epidemic curve for an epidemic of equine influenza (EI) in a closed population of horses predominantly immunologically naïve to EI at a 3-day event at Morgan Park in southern Queensland, Australia. The hazard function suggested that a subset of horses were at reduced risk of becoming infected. This highlights the importance, when modelling infectious disease in population...
Moloney B, Sergeant ES, Taragel C, Buckley P.Equine influenza (EI) was first diagnosed in the Australian horse population on 24 August 2007 at Centennial Park Equestrian Centre (CPEC) in Sydney, New South Wales (NSW), Australia. By then, the virus had already spread to many properties in NSW and southern Queensland. The outbreak in NSW affected approximately 6000 premises populated by approximately 47,000 horses. Analyses undertaken by the epidemiology section, a distinct unit within the planning section of the State Disease Control Headquarters, included the attack risk on affected properties, the level of under-reporting of affected pr...
Nogradi N, Slovis NM, Gebhart CJ, Wolfsdorf KE, McCracken JL, Scoggin CF, Kass PH, Mapes SM, Toth B, Lundquist ML, Pusterla N.Equine proliferative enteropathy caused by Lawsonia intracellularis is an emerging disease with as yet unaddressed preventative measures. The hypothesis of this study was that vaccination will prevent clinical and sub-clinical disease. Weanling Thoroughbreds (n=202) from Central Kentucky were randomly assigned into two groups (vaccinated and non-vaccinated). Vaccinated foals received 30 mL of an avirulent, live L. intracellularis vaccine intra-rectally twice, 30 days apart. Foals were monitored for clinical disease, total solids and average weight gain until yearling age. There was an overall ...
Chaffin MK, Cohen ND, Martens RJ, O'Conor M, Bernstein LR.To determine the chemoprophylactic effect of gallium maltolate on the cumulative incidence of pneumonia caused by Rhodococcus equi infection in foals. Methods: 483 foals born and raised on 12 equine breeding farms with a history of endemic R equi infections. Methods: Group 1 foals were treated with a placebo and group 2 foals were treated with gallium maltolate (approx 30 mg/kg, PO, q 24 h) during the first 2 weeks after birth. Foals were monitored for development of pneumonia attributable to R equi infection and for adverse effects of gallium maltolate. Results: There were no significant diff...
Mutebi JP, Lubelczyk C, Eisen R, Panella N, Macmillan K, Godsey M, Swope B, Young G, Smith RP, Kantar L, Robinson S, Sears S.Serum from 226 free-ranging white-tailed deer (Odocoileus virginianus) was screened for Eastern Equine Encephalitis Virus (EEEV) antibodies using plaque reduction neutralization tests. EEEV antibodies were detected in 7.1% of samples. This is the first time EEEV antibodies have been detected in O. virginianus populations in the state of Maine (ME). The highest percentage of EEEV positive sera was in Somerset County (19%) in central ME, and this is the first time that EEEV activity has been detected in that County. EEEV RNA was not detected in any of the 150 harvested deer brain samples submitt...
Endimiani A, Hujer KM, Hujer AM, Bertschy I, Rossano A, Koch C, Gerber V, Francey T, Bonomo RA, Perreten V.We investigated whether Acinetobacter baumannii isolates of veterinary origin shared common molecular characteristics with those described in humans. Methods: Nineteen A. baumannii isolates collected in pets and horses were analysed. Clonality was studied using repetitive extragenic palindromic PCR (rep-PCR) and multilocus sequence typing (MLST). PCR and DNA sequencing for various β-lactamase, aminoglycoside-modifying enzyme, gyrA and parC, ISAba1 and IS1133, adeR and adeS of the AdeABC efflux pump, carO porin and class 1/2/3 integron genes were performed. Results: Two main clones [A (n =â€...
Cutolo AA, Santos AT, Allegretti SM.Twenty horses naturally infected with nematodes were included in a blind, controlled field study on efficacy and safety of an oral 2% ivermectin formulation at a dose of 0.2 mg.kg(-1). Horses were divided into treated and non-treated (control) groups with ten animals each based on preliminary counts of eggs per gram of feces (EPG). Stool samples were collected after treatment for identification of nematode species. Clinical evaluations and EPG counts were performed on days 0, +5, +14 and +19. Nineteen nematode species were identified: Coronocyclus ulambajari, Craterostomum acuticaudatum, Cyath...
Hartl B, Hainisch EK, Shafti-Keramat S, Kirnbauer R, Corteggio A, Borzacchiello G, Tober R, Kainzbauer C, Pratscher B, Brandt S.Bovine papillomavirus types 1 and 2 (BPV-1 and BPV-2) are known to induce common equine skin tumours, termed sarcoids. Recently, it was demonstrated that vaccination with BPV-1 virus-like particles (VLPs) is safe and highly immunogenic in horses. To establish a BPV-1 challenge model for evaluation of the protective potential of BPV-1 VLPs, four foals were injected intradermally with infectious BPV-1 virions and with viral genome-based and control inocula, and monitored daily for tumour development. Blood was taken before inoculation and at weekly intervals. BPV-1-specific serum antibodies were...
Gaschen L, LeRoux A, Trichel J, Riggs L, Bragulla HH, Rademacher N, Rodriguez D.The magnetic resonance (MR) imaging findings of foals with infectious and noninfectious arthritis are described. Six foals with infectious arthritis and three foals with noninfectious arthritis were grouped based on synovial fluid analysis results and examined with radiography and MR imaging. Four out of six foals with infectious arthritis had osseous lesions in MR images indicative of osteomyelitis and only 4/19 lesions were detected on digital radiographs. The three foals with noninfectious arthritis had no osseous lesions in MR images or radiographically. Of the six joints that had osseous ...
Erdman MM, Creekmore LH, Fox PE, Pelzel AM, Porter-Spalding BA, Aalsburg AM, Cox LK, Morningstar-Shaw BR, Crom RL.Contagious equine metritis (CEM) is a highly contagious venereal disease of horses caused by Taylorella equigenitalis. During testing for semen export purposes, a stallion in Kentucky was found to be T. equigenitalis culture positive in December of 2008. This finding triggered an extensive regulatory investigation to search for additional positive horses, determine the extent of the outbreak, identify the potential source of the outbreak, and ultimately return the United States to CEM-free status. The investigation included over 1000 horses located in 48 states. Diagnostic testing found a tota...
Dujardin CL.A Belgian draft horse stallion presented with classical signs of purpura haemorrhagica: oedema of the distal limbs, ventral abdomen and head, ecchymotic haemorrhage of mucous membranes, epistaxis, fever, lethargy, reluctance to move, and anorexia. Serum chemistry revealed a highly elevated gamma-globulin fraction. Streptococcal lymphadenitis (strangles) had been present on a neighbouring farm in the past few months. After an initial positive response to therapy with benzylpenicillin, flunixin and dexamethasone, the horse's condition deteriorated suddenly on day 4 of hospitalization, with signs...
Pusterla N, Mapes S, Gebhart C.The cell-mediated immune response to Lawsonia intracellularis, the agent of equine proliferative enteropathy (EPE), was investigated in vaccinated and naturally infected foals. Interferon (IFN)-γ gene expression was determined in peripheral blood mononuclear cells collected from vaccinated (n=6) and control foals (n=6) every 30 days for 180 days following first vaccine administration, and from clinically affected foals (n=16) within 7-10 days of diagnosing EPE. Seroconversion (immunoperoxidase monolayer assay titer ≥60) occurred in 5/6 vaccinated foals between 60 and 90 days following the f...
Peters J, Block W, Oswald S, Freyer J, Grube M, Kroemer HK, Lämmer M, Lütjohann D, Venner M, Siegmund W.The delivery of clarithromycin (CRL) to its site of action in bronchial/alveolar epithelial cells (EC), bronchial epithelial lining fluid (ELF), and bronchoalveolar lavage cells (BALC) may be influenced by CYP3A4 and the drug transporters, ATP-binding cassette (ABC) B1 and ABCC2 and organic anion-transporting polypeptides (OATPs), which can be modulated and/or up-regulated via the nuclear pregnane X receptor (PXR) by rifampicin (RIF). Therefore, we evaluated the disposition and pulmonary distribution of CLR (7.5 mg/kg b.i.d., 21 days) and expression of ABCB1, ABCC2, OATP1A2, and OATP2B1 in EC ...
Boulanger D, Doucoure S, Grout L, Ngom A, Rogerie F, Cornelie S, Sokhna C, Mouchet F, Riveau G, Simondon F, Remoue FJ.Although domestic animals may not be permissive for Plasmodium, they could nevertheless play a role in the epidemiology of malaria by attracting Anopheles away from humans. To investigate interactions between domestic animals and mosquitoes, we assayed immunoglobulin G (IgG) antibodies directed against the salivary proteins of Anopheles gambiae in domestic animals living in Senegalese villages where malaria is endemic. By Western blotting, sera from bovines (n=6), ovines (n=36), and caprines (n=36) did not react with Anopheles whole saliva. In contrast, equine sera recognized proteins in both ...
Maestre AM, Garzón A, RodrÃguez D.Toroviruses are gastroenteritis causing agents that infect different animal species and humans. To date, very little is known about how toroviruses cause disease. Here, we describe for the first time that the prototype member of this genus, the equine torovirus Berne virus (BEV), induces apoptosis in infected cells at late times postinfection. Observation of BEV infected cells by electron microscopy revealed that by 24 hours postinfection some cells exhibited morphological characteristics of apoptotic cells. Based on this finding, we analyzed several apoptotic markers, and observed protein syn...
Pusterla N, Kass PH, Mapes S, Johnson C, Barnett DC, Vaala W, Gutierrez C, McDaniel R, Whitehead B, Manning J.The prevalence and epidemiology of important viral (equine influenza virus [EIV], equine herpesvirus type 1 [EHV-1] and EHV-4) and bacterial (Streptococcus equi subspecies equi) respiratory pathogens shed by horses presented to equine veterinarians with upper respiratory tract signs and/or acute febrile neurological disease were studied. Veterinarians from throughout the USA were enrolled in a surveillance programme and were asked to collect blood and nasal secretions from equine cases with acute infectious upper respiratory tract disease and/or acute onset of neurological disease. A questionn...
Selmi R, Dhibi M, Ben Said M, Ben Yahia H, Abdelaali H, Ameur H, Baccouche S, Gritli A, Mhadhbi M.Livestock constitute habitual hosts and carriers for several infectious pathogens which may represent a serious public health concern affecting the readiness of military forces and lead to wide economic losses. The present report aimed to investigate the prevalence of some haemopathogens infecting military livestock, particularly, dromedaries, sheep and horses using Giemsa-stained blood smears. A total of 300 animals (100 from each species) were selected, clinically examined and sampled. Trypanosoma spp. (22.0%), Anaplasma spp. (17.0%) and Babesia spp. (1.0%) were identified in camels' blood. ...
Sellers RF, Maarouf AR.Backward trajectories of winds were determined to identify possible sources of eastern equine encephalitis virus associated with isolation of virus from mosquitoes or birds or outbreaks in horses between 1980 and 1985 in Maryland, New Jersey, New York and Michigan, USA. The results of the trajectory analyses suggested that eastern equine encephalitis virus could have been carried by infected mosquitoes on surface winds at temperatures 13 degrees C or higher from North Carolina north-eastwards along the Atlantic Coast to Maryland and New Jersey and thence to upstate New York and from western Ke...
Hammerschmitt ME, Henker LC, Lichtler J, da Costa FVA, Soares RM, Llano HAB, Pavarini SP.Sarcocystis neurona is the main agent associated with equine protozoal myeloencephalitis (EPM). Apart from horses, S. neurona has been occasionally described causing neurologic disease in several other terrestrial animals as well as mortality in marine mammals. Herein, we describe the clinical, pathological, and molecular findings of a fatal case of S. neurona-associated meningoencephalitis in a domestic cat. The causing agent was analyzed by multilocus genotyping, confirming the presence of S. neurona DNA in the tissue samples of the affected animal. Significant molecular differences were fou...
Jaramillo-Morales C, James K, Barnum S, Vaala W, Chappell DE, Schneider C, Craig B, Bain F, Barnett DC, Gaughan E, Pusterla N.This study aimed to describe selected epidemiological aspects of horses with acute onset of fever and respiratory signs testing qPCR-positive for and to determine the effect of vaccination against on qPCR status. Horses with acute onset of fever and respiratory signs from all regions of the United States were included in a voluntary biosurveillance program from 2008 to 2020 and nasal secretions were tested via qPCR for and common respiratory viruses. A total of 715/9409 equids (7.6%) tested qPCR-positive for , with 226 horses showing coinfections with EIV, EHV-1, EHV-4, and ERBV. The median...
Wohlfender FD, Barrelet FE, Doherr MG, Straub R, Meier HP.The development of clinical illness in foals is usually predetermined by perinatal history, management or stressful environmental conditions. Objective: To determine potential risk factors for an increased incidence of infectious diseases during the first 30 days post partum. Methods: The population consisted of Thoroughbred foals born on stud farms in the Newmarket (UK) area in 2005 (n = 1031). They were followed for their first 30 days. Factors suspected to influence the incidence of infectious neonatal diseases were examined in a logistic regression approach for each of the 3 outcomes (tota...
Wangdi C, Picard J, Tan R, Condon F, Dowling B, Gummow B.Determine leptospiral serodiversity, serodominant serovars and prevalence in the horse population of Northern Queensland (NQ), Australia, with special focus on the Atherton Tableland and Townsville-Burdekin regions. Methods: Cross-sectional survey. Methods: Serum samples from 429 horses originating from 172 horse-owning properties in NQ were collected at regional horse shows and veterinary clinics. Samples were analysed using a microscopic agglutination test. Owners were interviewed on potential risk factors associated with leptospirosis. Results: Of the 172 properties that submitted samples, ...
Witkowski L, Rzewuska M, Takai S, Chrobak-Chmiel D, Kizerwetter-Åšwida M, Feret M, GawryÅ› M, Witkowski M, Kita J.Rhodococcus equi is one of the most significant bacterial pathogens affecting foals up to 6Â months of age worldwide. Rhodococcosis is present in Poland however information about molecular characterization of R. equi isolates is scarce. This study describes molecular characterization of Rhodococcus equi infection on 13 horse breeding farms in Poland between 2001 and 2012. Samples were collected by tracheobronchial aspiration from pneumonic foals or during necropsy. The R. equi isolates were genotyped by plasmid profiling and pulsed-field gel electrophoresis. Results: Totally, 58 R. equi isolat...
Tartor YH, El-Naenaeey EY, Gharieb NM, Ali WS, Ammar AM.Strangles displays a major challenge to veterinary medicine worldwide. However, no data on Streptococcus equi subsp. equi (S. equi) M protein alleles have been reported so far from Arabian horses. We report here for the first time the S. equi SeM alleles causing strangles in Arabian horses, and the associated risk factors for the disease. Duplicate samples from one hundred Arabian horses with acute strangles in confirmed outbreaks and sporadic cases were analysed by phenotypic methods and multiplex polymerase chain reaction (PCR) targeting streptokinase precursor, seeI and sodA genes. PCR and ...
Mostafavi E, Esmaeilnejad B, Meysam Abtahi Foroushani S.This study was undertaken to assess the effects of T. equi infection on serum concentrations of some important cytokines including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and interleukin-1 beta (IL-1β), IL-1α, IL-4, IL-6, IL-8, IL-10, IL-12α, IL-12β, IL-18, as well as total, protein and lipid binding sialic acids (TSA, PBSA and LBSA). Furthermore, any probable relation among the parasitemia, cytokines and sialic acids (SAs) were calculated using Pearson correlation and simple linear regression. Almost 300 draft horses (Kurdish-breed) with age of 3-4 years old from north-...
Corapi WV, Snowden KF, Rodrigues A, Porter BF, Buote MA, Birch SM, Jackson ND, Eden KB, Whitley DB, Mansell J, Edwards JF, Hardy J, Chaffin MK.The schistosome Heterobilharzia americana infects dogs, raccoons, and other mammals in the southeastern United States. Migration of eggs into the liver results in parasitic granulomas with varying degrees of fibrosis and inflammation. Recently, hepatic parasitic granulomas in horses were shown to be caused by H. americana infection. In the present study, samples of liver from 11 of 12 horses with hepatic granulomas identified at necropsy (n = 11) or surgical biopsy (n = 1) were used for DNA extraction, polymerase chain reaction amplification and sequencing using primers specific for a portion ...
Godsey MS, Amoo F, Yuill TM, Defoliart GR.A serologic survey and experimental virus transmission studies were done to assess the role of domestic animals as amplifier hosts of La Crosse (LACV) and Jamestown Canyon (JCV) viruses. Serum from 319 cows, 88 dogs, 122 equines, 47 swine, 10 goats, and 4 cats were tested for neutralizing antibody to LACV, JCV, trivittatus (TVTV), and snowshoe hare (SSHV) viruses. Antibody prevalences of LACV, TVTV, and SSHV were less than 10% in all species. Antibody to JCV was detected in all species except cats. Prevalence ranged from 10% in goats and swine to 29% in dogs. No age-associated trends in JCV pr...
Elzer EJ, Wulster KB, Richardson DW, Ortved KF.A 15-year-old Thoroughbred gelding was presented for investigation of fever, right temporomandibular region swelling, and progressive pain when opening the mouth. Right temporomandibular joint (TMJ) sepsis was diagnosed based on synovial fluid analysis, sonographic imaging, and standing robotic cone-beam computed tomography. Concurrent otitis media and temporohyoid osteoarthropathy (THO) were also noted. The horse was treated with arthroscopic debridement and lavage during standing sedation followed by local and systemic antimicrobial therapy. There were no complications associated with the su...
Hartley CA, Wilks CR, Studdert MJ, Gilkerson JR.To compare methods of detecting equine herpesvirus type 1 (EHV1)- and EHV4-specific antibodies in horse sera. Methods: 33 acute and convalescent serum samples from experimentally or naturally infected horses after confirmed EHV1 or EHV4 infection. Methods: For each sample, serum antibody titers against EHV1 and EHV4 were determined by use of virus neutralization (VN) and complement fixation (CF) assays. The ELISA absorbance values for each serum sample were determined against the EHV1 and EHV4 recombinant ELISA antigens. Values obtained for acute and convalescent sera in each assay were compar...
Montelaro RC, West M, Issel CJ.The immunogenic contributions of the carbohydrate and peptide portions of the major envelope glycoprotein of equine infections anemia virus, EIAV gp90, were analyzed by measuring the effects of specific glycosidase and protease digestions on the reactivity of the glycoprotein with immune sera from infected horses. The results of both direct and competitive radioimmunoassay demonstrated that immune sera contained antibodies reactive with both the carbohydrate and protein moieties of EIAV gp90, with the predominant reactivity apparently against the gp90 peptide epitopes. These results contrast w...
de Siqueira SM, da Costa Maia R, do Nascimento Ramos V, da Silva Rodrigues V, Szabó MPJ.We herein describe zebuine cattle tick infestation in a farm in southeast Brazil with an examination accurate enough to detect tick immatures and species other than R. microplus. Cattle were inspected monthly for ticks from May 2015 to May 2017 and 7604 ticks were collected along 276 bovine inspections. Rhipicephalus microplus was the dominant species (7197 specimens, 94.5% from the total), but Amblyomma sculptum was also collected (407/5.5%). Horse tick infestations were evaluated for comparison purposes of A. sculptum infestations of a primary host sharing pastures with bovines. Ticks were c...
Rossano MG, Mansfield LS, Kaneene JB, Murphy AJ, Brown CM, Schott HC, Fox JC.Equine protozoal myeloencephalitis (EPM) is a neurological disease of horses and ponies caused by the apicomplexan protozoan parasite Sarcocystis neurona. The purposes of this study were to develop the most stringent criteria possible for a positive test result, to estimate the sensitivity and specificity of the EPM Western blot antibody test, and to assess the ability of bovine antibodies to Sarcocystis cruzi to act as a blocking agent to minimize false-positive results in the western blot test for S. neurona. Sarcocystis neurona merozoites harvested from equine dermal cell culture were heat ...
Nielsen MK, Facison C, Scare JA, Martin AN, Gravatte HS, Steuer AE.Strongylus vulgaris is the most pathogenic intestinal helminth parasite infecting horses. The migrating larvae in the mesenteric blood vessels can cause non-strangulating intestinal infarctions, which have a guarded prognosis for survival. Infections are typically diagnosed by coproculture, but a PCR test is available in some countries. While it is ideal to test horses individually, many veterinarians and clients wish to pool samples to reduce workload and cost of the diagnostic method. The purpose of this study was to determine if pooling of fecal samples would negatively impact diagnostic pe...
Guarino C, Asbie S, Rohde J, Glaser A, Wagner B.Borrelia burgdorferi can induce Lyme disease. Approved Lyme vaccines for horses are currently not available. In an effort to protect horses, veterinarians are using Lyme vaccines licensed for dogs. However, data to assess the response of horses to, or determine the efficacy of this off-label vaccine use are missing. Here, antibodies against outer surface protein A (OspA), OspC, and OspF were quantified in diagnostic serum submissions from horses with a history of vaccination with canine Lyme vaccines. The results suggested that many horses respond with low and often short-lasting antibody resp...
Paruch L, Paruch AM.Zoogenic faecal contamination of the environment is one of the indices included in the evaluation of ecological threats, health hazards and adverse impacts on various ecosystems. The risks and environmental concerns are associated with the fact that faeces of wild and domesticated animals constitute the largest source of environmental loading of enteropathogens associated with transmission of zoonotic diseases (enteric zoonoses). Although sick animals are more likely to transmit pathogens, healthy ones can also be the carriers and defecate them into the environment. This is of particular impor...
Cao X, Yang D, Parvathareddy J, Chu YK, Kim EJ, Fitz-Henley JN, Li X, Lukka PB, Parmar KR, Temrikar ZH, Dhole P, Adcock RS, Gabbard J, Bansal S....Venezuelan and eastern equine encephalitis viruses (VEEV and EEEV, respectively) are mosquito-borne, neuroinvasive human pathogens for which no FDA-approved therapeutic exists. Besides the biothreat posed by these viruses when aerosolized, arthropod transmission presents serious health risks to humans, as demonstrated by the 2019 outbreak of EEE disease in the United States that resulted in 38 confirmed cases, 19 deaths, and neurological effects in survivors. Here, we describe the discovery of a 2-pyrrolidinoquinazolinone scaffold, efficiently synthesized in two to five steps, whose structural...
Perkins NR, Webster WR, Wright T, Denney I, Links I.At the time of the initial notification of the occurrence of equine influenza (EI) in Australia in August 2007, vaccination was restricted to horses for which it was an import requirement and only with the approval of the state or territory Chief Veterinary Officer. This paper describes the complexities involved in the selection of a vaccine and its distribution. A combination of ring, predictive and blanket vaccination was implemented during the response. The specific vaccination programs, including its use in buffer zones and for movement of horses, the performance of the vaccine, any advers...
Johnson AL, McAdams-Gallagher SC, Sweeney RW.Botulism in horses in the USA is attributed to Clostridium botulinum types A, B or C. In this study, a duplex quantitative real-time PCR (qPCR) for detection of the neurotoxin genes of C. botulinum types A and B, and a singleplex qPCR for detection of the neurotoxin gene of C. botulinum type C, were optimized and validated for equine gastrointestinal, faecal and feed samples. The performance of these assays was evaluated and compared to the standard mouse bioassay (MBA) using 148 well-characterized samples, most of which were acquired from a repository of veterinary diagnostic samples from cas...
Cwiklinski K, Kooyman FN, Van Doorn DC, Matthews JB, Hodgkinson JE.Cyathostomins comprise a group of 50 species of parasitic nematodes that infect equids. Ribosomal DNA sequences, in particular the intergenic spacer (IGS) region, have been utilized via several methodologies to identify pre-parasitic stages of the commonest species that affect horses. These methods rely on the availability of accurate sequence information for each species, as well as detailed knowledge of the levels of intra- and inter-specific variation. Here, the IGS DNA region was amplified and sequenced from 10 cyathostomin species for which sequence was not previously available. Also, add...
Maxson AD, Reef VB.A retrospective study of 10 horses with bacterial endocarditis was performed in order to describe the echocardiographic findings in horses with bacterial endocarditis, in conjunction with clinical signs and post mortem findings, and to evaluate the usefulness and the formulation of a prognosis. Echocardiographic and post mortem examinations were performed in 7 horses. Post mortem examination alone was performed in 2 horses and echocardiographic examination alone performed in one horse. No breed or sex predilection was obvious. Mean age +/- s.d. was 2.12 +/- 3.32 years. Predominant clinical sig...
Smith LJ, Marr CM, Payne RJ, Stoneham SJ, Reid SW.Septic arthritis is a serious problem in the neonate, with a poor prognosis being reported for recovery. The impact of neonatal septic arthritis on the likelihood that Thoroughbred (TB) foals will start on a racecourse is not known. Objective: The development of septic arthritis in a TB foal significantly reduces the likelihood that it will race when compared to foals from the same dam. Methods: Medical records of 69 foals treated for septic arthritis were reviewed. The dam's foaling records were reviewed and lifetime racing records were then retrieved for both the affected foals and at least ...
Hurcombe SD.Hypothalamic-pituitary (HP) dysfunction has been documented in a limited capacity in horses and foals associated with critical illness, stress, and pain. This article reviews species-specific details of anatomy, function, hormones, receptors, and testing of the HP axis in the horse. A discussion of critical care medicine relevant to HP dysfunction in the horse with some reference to current understanding in human medicine is made, focusing primarily on current and relevant literature. A brief mention of other conditions described in human and veterinary medicine is also provided for reference ...
Tan LP, Mohd Rajdi NZI, Mohamad MA, Mohamed M, Hamdan RH, Goriman Khan MAK, Ahmad Syazwan S, Seng Hua L.Trypanosoma (Megatrypanum) theileri is a non-pathogenic or weakly pathogenic parasite of domestic cattle that is cyclically transmitted by blood-sucking insects, mainly tabanid flies. It has been reported in several countries like Brazil, Venezuela, Japan, Taiwan, Thailand, Vietnam, and the Philippines. Although the ruminant industry is actively expanded in Malaysia, T. theileri and T. theileri-like trypanosomes have never been reported from Malaysia. The low pathogenicity of this species might be the main reason for overlooking T. theileri in this country. This paper describes an unforeseen f...
Ogunnariwo JA, Alcantara J, Schryvers AB.Two clinical isolates of Pasteurella multocida associated with bovine pneumonia were examined for iron acquisition. Both isolates were capable of obtaining iron for growth from bovine but not from human, avian, equine or porcine transferrin. This correlated with specific binding of bovine transferrin by iron-limited cells or isolated membranes. No siderophore was detected in the strains by a general screening assay. In response to iron-limited conditions, a number of high molecular mass iron-regulated outer membrane proteins were produced including an 82 kDa receptor protein which was affinity...
Smith BP.The practical implications of equine salmonellosis in the light of present knowledge are reviewed. Emphasis is placed on the various clinical forms which the disease may take. These include asymptomatic infections, signs of fever, anorexia and depression, severe acute diarrhoea and the septicaemic form. Diagnosis depends on recovery of the organism from the blood or faeces or, at necropsy, from tissues. In asymptomatic infections, it may be necessary to make serial faecal cultures over several days before a negative diagnosis may be made with any degree of certainty. Isolation of salmonellae i...
