Epidemiology in horses involves the study of the distribution and determinants of health-related states and events in equine populations. It encompasses the investigation of patterns, causes, and effects of diseases and health conditions within horse populations. This field of study aims to identify risk factors for disease and targets for preventive healthcare. Key components of equine epidemiology include disease surveillance, outbreak investigation, and the study of disease dynamics within herds or regions. Research in this area often focuses on infectious diseases, zoonotic diseases, and the impact of environmental factors on equine health. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of epidemiology in horses, including disease prevalence, transmission pathways, and strategies for disease prevention and control.
Peterson AE, Davis MF, Awantang G, Limbago B, Fosheim GE, Silbergeld EK.Animals on farms may be a potential reservoir and environmental source of methicillin-resistant Staphylococcus aureus (MRSA). Expanded surveillance methods for animal-associated MRSA are needed. To develop an environmental sampling method and to determine the correlation between animal and environmental MRSA positivity in the farm setting, we sampled horses, cattle, and their local environments at several farms in the mid-Atlantic United States. We obtained nasal swabs from 13 racehorses at first visit, and 11 racehorses at the same farm eight weeks later. We also sampled 26 pleasure horses an...
Ebani VV, Bertelloni F, Pinzauti P, Cerri D.The aim of the study was to determine the seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in healthy horses living in 7 provinces of central Italy. In the period 2007-2009, sera from 386 horses were tested by microagglutination test (MAT) to detect antibodies to Leptospira spp., employing the following serovars as antigens: Bratislava, Ballum, Canicola, Icterohaemorrhagiae, Grippotyphosa, Hardjo, Pomona, Tarassovi. 3 animals were positive for the serovars Icterohaemorrhagiae, 2 to Bratislava, and 1 to Pomona, for a total 1.5% seroprevalence. All sera were examined by immu...
Karakulska J, Fijałkowski K, Nawrotek P, Pobucewicz A, Poszumski F, Czernomysy-Furowicz D.The aim of this study was an analysis of the staphylococcal flora of the nasal cavity of 42 healthy horses from 4 farms, along with species identification of CoNS isolates and determination of resistance to 18 antimicrobial agents, particularly phenotypic and genotypic methicillin resistance. From the 81 swabs, 87 staphylococci were isolated. All isolates possessed the gap gene but the coa gene was not detected in any of these isolates. Using PCR-RFLP of the gap gene, 82.8% of CoNS were identified: S. equorum (14.9%), S. warneri (14.9%), S. sciuri (12.6%), S. vitulinus (12.6%), S. xylosus (11....
Schoster A, Arroyo LG, Staempfli HR, Shewen PE, Weese JS.Clostridium difficile and Clostridium perfringens are commonly associated with colitis in equids, but healthy carriers exist. Scarce information is available on the prevalence of Clostridium spp. in gastrointestinal compartments other than faeces in healthy horses, and it is unknown whether faecal samples are representative of proximal compartments. The objectives were to investigate the prevalence of C. difficile and C. perfringens in different intestinal compartments of healthy adult horses and to determine whether faecal samples are representative of colonization in proximal sites and overa...
Pawelek KA, Huynh GT, Quinlivan M, Cullinane A, Rong L, Perelson AS.Influenza virus infection remains a public health problem worldwide. The mechanisms underlying viral control during an uncomplicated influenza virus infection are not fully understood. Here, we developed a mathematical model including both innate and adaptive immune responses to study the within-host dynamics of equine influenza virus infection in horses. By comparing modeling predictions with both interferon and viral kinetic data, we examined the relative roles of target cell availability, and innate and adaptive immune responses in controlling the virus. Our results show that the rapid and ...
Barrandeguy M, Vissani A, Olguin C, Barbara G, Valenzuela H, Becerra L, Tordoya M, Miño S, Thiry E.Equine coital exanthema (ECE), caused by equid herpesvirus 3 (EHV-3), has been recognized as an economically significant venereal disease for years. However, no infection models on the natural host have been established. In order to set up an experimental infection protocol, seronegative and seropositive mares were topically inoculated in the perineal region with 4 × 10(6)TCID(50)/ml of EHV-3. Clinical signs were then evaluated by means of a designed scoring system, and body temperature was recorded daily. Virological, and serological studies were also performed. Typical ECE lesions, with cli...
García-Bocanegra I, Arenas-Montes A, Napp S, Jaén-Téllez JA, Fernández-Morente M, Fernández-Molera V, Arenas A.West Nile virus (WNV) is recognized as an emerging zoonotic pathogen, whose incidence in horses, humans and birds has increased significantly in different European countries in the last decade. A serosurvey study was carried out in non vaccinated horses to determine the geographical distribution of WNV in Andalusia (Southern Spain), and to assess the factors that influence the risk of WNV infection in horses. Antibodies to WNV were detected in 54 out of 510 horses analyzed by a blocking ELISA, of which 36 were confirmed by micro virus neutralization test (7.1%; CI(95%): 4.9-9.3). A total of 28...
Vaughan JA, Tkach VV, Greiman SE.Digeneans are endoparasitic flatworms with complex life cycles and distinct life stages that parasitize different host species. Some digenean species harbour bacterial endosymbionts known as Neorickettsia (Order Rickettsiales, Family Anaplasmataceae). Neorickettsia occur in all life stages and are maintained by vertical transmission. Far from benign however, Neorickettsia may also be transmitted horizontally by digenean parasites to their vertebrate definitive hosts. Once inside, Neorickettsia can infect macrophages and other cell types. In some vertebrate species (e.g. dogs, horses and humans...
Donahue JM, Timoney PJ, Carleton CL, Marteniuk JV, Sells SF, Meade BJ.This study was undertaken to investigate the prevalence of Taylorella asinigenitalis in a subset of the donkey population of Michigan and in other equids on farms on which the organism was identified. Other aims were to further characterize the carrier state in terms of persistence and preferred sites of colonization of T. asinigenitalis in the male donkey as well as determine the genotype of any isolates of the organism. Initial testing of 43 donkeys and 1 mule turned up 4 (9.3%) donkeys culture positive for T. asinigenitalis. The 4 culture-positive donkeys resided on 2 farms accommodating a ...
Liccardi G, Emenius G, Merritt AS, Salzillo A, D'Amato M, D'Amato G.Most studies on the sensitization to horse allergens in populations without professional exposure have been carried out in geographical areas where the rate of horse ownership is high and horse riding is popular. Very few studies have been carried out in populations living in large urban areas. This gap in the literature probably reflects the widespread view that prevalence of horse-related allergy is low in urban populations because the latter are not regularly exposed to horses. On the contrary, we suggest that urban areas constitute a model useful to study potential modalities of exposure a...
Malik P, Singha H, Khurana SK, Kumar R, Kumar S, Raut AA, Riyesh T, Vaid RK, Virmani N, Singh BK, Pathak SV, Parkale DD, Singh B, Pandey SB....Glanders, a bacterial disease of equines caused by Burkholderia mallei, is a fatal infectious disease of equines and has zoonotic significance. The disease has been eradicated from many countries by statutory testing, elimination of infected animals and import restrictions. However, it is still endemic in parts of Africa, Asia, the Middle East and Central and South America. In India, major glanders outbreaks were reported from different parts of the country between 1976 and 1982. Later, sporadic cases of the disease were reported in 1988, 1990 and 1998. The country remained free of glanders fo...
Bolwell CF, Rogers CW, French NP, Firth EC.To quantify the time from the start of training to the first interruption and to identify horse and training risk factors for voluntary interruptions and interruptions due to musculoskeletal injury occurring before the first trial. Methods: A prospective cohort study was used to collect data on the training activity of 2-year-old racehorses, from 14 trainers in the Northern and Central Districts of New Zealand, over two racing seasons (2008/09 and 2009/10). Daily training data were recorded for each horse, including, distances worked at canter (>15 seconds/200 m), three measures of high-spe...
Kalisiak O.Flexor tendonitis and suspensory desmitis are among most prevalent musculoskeletal injuries observed in racehorses. The aim of this study was to determine which horse and race-related parameters can help to diminish the possibility of injury or--when injury has occurred--to evaluate the potential for the horse to continue a successful career after convalescence. Special attention was given to the comparison of Arabian and Thoroughbred racehorses. 187 horses with ultrasonographically visible lesions were included in the study. Following parameters were analyzed: structure (Superficial Digital F...
Vannucci FA, Pusterla N, Mapes SM, Gebhart C.Lawsonia intracellularis is the causative agent of proliferative enteropathy, an endemic disease in pigs and an emerging concern in horses. Enterocyte hyperplasia is a common lesion in every case but there are differences regarding clinical and pathological presentations among affected species. We hypothesize that host susceptibility to L. intracellularis infection depends on the species of origin of the bacterial isolate. The objective of this study was to evaluate the susceptibilities of pigs and horses to L. intracellularis infection using either a porcine or an equine isolate. Methods: Twe...
Gulati BR, Singha H, Singh BK, Virmani N, Kumar S, Singh RK.Japanese encephalitis (JE) is an important vector-borne viral disease of humans and horses in Asia. JE outbreaks occur regularly amongst humans in certain parts of India and sporadic cases occur among horses. In this study, JE seroprevalence and evidence of JE virus (JEV) infection among horses in Haryana (India) is described. Antibodies against JEV were detected in 67 out of 637 (10.5%) horses screened between 2006 and 2010. Two foals exhibiting neurological signs were positive for JEV RNA by RT-PCR; JEV was isolated from the serum of one of the foals collected on the second day of illness. T...
Walker H, Chinn E, Holmes S, Barwise-Munro L, Robertson V, Mould R, Bradley S, Shaw DJ, Dixon PM.Cheek teeth (CT) diastemata are now recognised as a clinically significant equine disorder, but their prevalence in the general equine population is unknown. There is also limited information on the signalment of affected horses; the more commonly affected Triadan sites; and the shape and clinical characteristics of CT diastemata. During the 12-month study period (2008 to 2009), standardised records were obtained during routine dental examinations performed by five veterinarians in a first-opinion equine practice. Cheek teeth diastemata were identified in 49.9 per cent of all horses (n=471) of...
Rosanowski SM, Rogers CW, Cogger N, Benschop J, Stevenson MA.A survey was conducted to investigate biosecurity practices on non-commercial horse properties, to describe the number of visits by horse professionals and any protocols that visitors were required to follow before interacting with resident horses. Data were collected in November 2009 during a cross-sectional study of non-commercial horse properties, in New Zealand, selected using generalised random-tessellated stratified design and a self-administered postal questionnaire. Data were described and the associations between property-level factors and biosecurity practices were analysed using log...
Durham AC, Pillitteri CA, San Myint M, Valli VE.Lymphoma is the most common malignant neoplasm in the horse. Single case reports and small retrospective studies of equine lymphomas are reported infrequently in the literature. A wide range of clinical presentations, tumor subtypes, and outcomes have been described, and the diversity of the results demonstrates the need to better define lymphomas in horses. As part of an initiative of the Veterinary Cooperative Oncology Group, 203 cases of equine lymphoma have been gathered from 8 institutions. Hematoxylin and eosin slides from each case were reviewed and 187 cases were immunophenotyped and c...
Müller A, Bertram A, Moschos A.Evaluation of the differences in the selenium supply to horses across Europe. Methods: Serum samples from 137,152 horses all over Europe, which had been sent by veterinarians to IDEXX Vet Med Labor between January 1st 2006 and December 31st 2011, were routinely analyzed for the selenium concentration by means of ICP-analytic. Results: The selenium content of the soil appears to play a key role in the selenium supply to horses. Countries closer to the ocean provided a better selenium supply than countries in central Europe. The best selenium supply can be seen in Denmark and in the Netherlands....
Jiménez-Clavero MÁ.Environmental changes have an undoubted influence on the appearance, distribution, and evolution of infectious diseases, and notably on those transmitted by vectors. Global change refers to environmental changes arising from human activities affecting the fundamental mechanisms operating in the biosphere. This paper discusses the changes observed in recent times with regard to some important arboviral (arthropod-borne viral) diseases of animals, and the role global change could have played in these variations. Two of the most important arboviral diseases of animals, bluetongue (BT) and West Ni...
Mukherjee S, Moody EE, Lewokzco K, Huddleston DB, Huang J, Rowland ME, Wilson R, Dunn JR, Jones TF, Moncayo AC.Human and equine outbreaks caused by eastern equine encephalomyelitis virus (EEEV) typically occur in North America adjacent to coastal wetlands associated with the presence of Culiseta melanura (Coquillet) mosquitoes. Eastern equine encephalomyelitis (EEE) is an emerging disease in Tennessee, as the first records of equine disease began in 2002. In 2006 we trapped and tested mosquitoes for EEEV at hardwood swamps in western Tennessee that were at the epicenter of a multi-equine outbreak in fall of 2005. Additionally, the Tennessee Valley Authority tested mosquito pools collected in Tennessee ...
Friesen KM, Johnson GD.Reproductive potential was assessed for stable fly cohorts fed cattle, chicken, or horse blood. Flies provided chicken blood oviposited 20% more eggs per day than did those fed cattle or horse blood. However, flies provided cattle or horse blood were fecund 50% longer. When both egg viability and number of eggs produced were considered, lifetime reproductive potential was almost twice as high for flies fed cattle or chicken blood than for flies fed horse blood. Maternal investment, which took egg production and volume into account, was higher in cohorts fed cattle blood (70 mm3) when compared ...
Baldacchino F, Cadier J, Porciani A, Buatois B, Dormont L, Jay-Robert P.Urine volatiles from different ungulates (cows, horses and sheep) were tested as bait for tabanids in southeastern France using Nzi traps during the early summer of 2011. Tabanus bromius Linnaeus, 1758 and Atylotus quadrifarius (Loew, 1874) (both: Diptera: Tabanidae) were the most captured species, respectively representing 57% and 41% of all tabanids collected (all of which were female). Horse urine significantly increased catches of T. bromius (1.6-fold) and A. quadrifarius (3.5-fold), and sheep urine significantly increased catches of A. quadrifarius (2.5-fold). In parallel, an electroanten...
Filby M, Jackson C, Turner M.The horseracing training industry has largely been ignored in terms of active occupational health research. Objective: To provide baseline statistics on the specific nature and type of accidents that occurred in English horseracing stables during 2008. Methods: All 716 training yards/stables registered with the British Horseracing Authority were contacted in April/May 2009 to complete the Racing Injury Accident Statistical Survey. The survey asked respondents to detail all recorded accidents and injuries during 2008. Results: Two hundred and fifty-six yards (36%) provided usable responses. The...
Tauro L, Marino B, Diaz LA, Lucca E, Gallozo D, Spinsanti L, Contigiani M.St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) present ecological and antigenic similarities and are responsible for serious human diseases. In addition, WNV is a significant pathogen in terms of equine health. The purpose of our study was to analyse the seroprevalence of SLEV and WNV in equine sera collected in Santa Fe Province, Argentina. The seroprevalence determined using the plaque reduction neutralisation test was 12.2% for SLEV, 16.2% for WNV and 48.6% for a combination of both viruses. These results provide evidence of the co-circulation of SLEV and WNV in equines in Sa...
Lan DL, Wang CS, Deng B, Zhou JP, Cui L, Tang C, Yue H, Hua XG.West Nile virus (WNV) infection is an emerging zoonosis that threatens global public health. In this study, a total of 95 bird serum samples from 14 species and 341 horse serum samples were collected from 2008 to 2010 in Shanghai, China. All serum samples were screened initially for WNV-reactive antibodies using a competitive ELISA. The positive samples detected by ELISA were further confirmed using a plaque-reduction neutralization test (PRNT) for WNV and its most closely related flaviviruses in the area to avoid false positives due to cross-reactivity. Five (5·3%) of the bird serum samples ...
Walter J, Neuberg KP, Failing K, Wehrend A.Aim of this study was to compare uterine smears made using the Knudsen catheter, the cytology brush and a uterine culture swab with regard to diagnostic usefulness and the occurrence of neutrophils. Additionally correlation between culture results and the occurrence of neutrophils in uterine smears was investigated. Samples were collected from 340 mares, 81.5% of which were in estrus. Smears made using the cytology brush yielded more endometrial cells per high-power field than those made using the other two instruments (p<0.0001), and a larger proportion had PMNs compared with smears made u...
Khan I, Wieler LH, Melzer F, Elschner MC, Muhammad G, Ali S, Sprague LD, Neubauer H, Saqib M.Glanders or farcy, caused by Burkholderia mallei, is an infectious and zoonotic disease of solipeds. Horses, donkeys and mules are the only known natural reservoir of B. mallei. Although glanders has been eradicated from most countries, it has regained the status of a re-emerging disease because of the numerous recent outbreaks. Pre-symptomatic or carrier animals are the potential source of infection for the healthy equine population and play a crucial role in the spreading of the infectious agent. Glanders is characterized by ulcerating nodular lesions of the skin and mucous membrane. Genera...
Ehizibolo DO, Kamani J, Ehizibolo PO, Egwu KO, Dogo GI, Salami-Shinaba JO.This study was conducted to determine the prevalence and significance of parasites of horses in northern Nigeria. Blood and faecal samples were randomly collected from 243 horses from different stables in some states of northern Nigeria for laboratory analyses. Fifty-seven horses (23.5%) were found infected with parasites. The hemoparasites detected, 21 (8.6%), include Theileria equi, Babesia caballi, Trypanosoma vivax and Trypanosoma evansi. The endoparasites encountered, 29 (11.9%) were Strongylus spp., Strongyloides spp., Oxyuris equi, Parascaris equorum, Paragonimus spp. and Dicrocoelium s...
Crispe EJ, Lester GD.Exercise-induced pulmonary hemorrhage (EIPH) occurs commonly in horses undergoing strenuous exercise. Reported risk factors include racing in cold temperatures and wearing of bar shoes. In horses with documented moderate to severe EIPH, increasing the interval between races and adopting a negative race pace strategy may reduce the severity of EIPH in subsequent races. EIPH seems to have an impact on performance only when moderate to severe. This occurs in a small number of starters, approximately 6%. EIPH often is erratic in severity from race to race, although across a population it is weakly...
Platt H, Singh H, Whitwell KE.A description is given of the pathological changes present in 8 mares which died or were euthanased in the course of an outbreak of paralysis on a Thoroughbred studfarm. In all cases the principal changes were in the central nervous system (CNS) and consisted of a severe and widespread vaculitis in the brain, cord, sheaths of nerves, capsules of ganglia and occasionally elsewhere in the body. Associated with the damage to vessel walls there was haemorrhage and exudation of plasma into the perivascular tissues. Involvement of neurones was minimal and no neuronophagia was present. Six cases had ...
Barnard BJ.The entry of Culicoides species into stables was examined by comparing the numbers of midges caught with identical light-traps under different conditions. The comparison was made between collections made inside an empty stable, a regularly cleaned stable and a dirty stable and those made outside the stables in a sleeping space open on two sides. The work was first done in the presence of cattle and sheep in adjoining paddocks and then repeated in their absence. A positive correlation was found between the numbers of C. imicola females caught out of doors and inside a clean stable. Removal of t...
Dieckmann SM, Hoelzle K, Dieckmann MP, Straube I, Hofmann-Lehmann R, Hoelzle LE.Hemotrophic mycoplasmas (HM) are small, cell wall-less bacteria and infections are known for a wide range of animals. One possible indication of equine HM infection was given in 1978, when a 'haemobartonellosis' outbreak was diagnosed in Nigerian horses by microscopy. However the first molecular proof of HM in horses was not reported until 2010, when a fragment of about 900 bp of the 16S rRNA of the equine HM was obtained. This sequence was used for the development of a SYBR green I real-time PCR assay specific for equine HM. The lower detection limit of the PCR was ten 16S rDNA copy numbers p...
Hu Y, Jia Q, Liu J, Sun W, Bao Z, Che C, Wu G, Fan B, Jarhen , Ran D.Equid alphaherpesvirus 1 (EHV-1) is prevalent in China, and causes notable economic damage to the equine industry. However, there is no information regarding the molecular characteristics and pathogenicity of the Chinese strains. Therefore, an EHV-1 strain, named YM2019, was isolated from the lung tissue of an aborted horse fetus in Xinjiang, China, and its genome and pathogenicity were analyzed. The full genome of the isolate was 150,267 base pairs in length, with 56.7% G + C content. Genetic and phylogenetic analysis showed that strain YM2019 (GenBank: MT063054) belonged to the ORF30 N75...
Durham AE, Kemp-Symonds J.Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined. Objective: The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi. Methods: Retrospective clinical study. Methods: As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibo...
Eysker M, Boersema JH, Kooyman FN.Two groups of three yearling Shetland ponies were used in 1988 to study the epidemiological significance of inhibited development of the Cyathostomine nematodes. In Group 1, acquisition of infections was prevented throughout the grazing season whereas in Group 2 strongylid infections were acquired from the beginning of July until the end of September. Worm counts showed that the Cyathostomine nematode populations of Group 1 ponies mainly consisted of adult worms and those of Group 2 ponies of inhibited early third stage larvae (L3). These results indicate that a large proportion of Cyathostomi...
Jaramillo-Morales C, Gomez DE, Renaud D, Arroyo LG.The objectives of this study were to determine the prevalence of S. equi in a horse population in Colombia, to determine the risk factors associated with its detection in the guttural pouches and to report the antimicrobial susceptibility of the isolates. Fifteen farms and 137 horses >6 months of age were enrolled. Sampling was randomly, stratified and proportional to the population size of each farm. The guttural pouch (GP) was swabbed via endoscopic guidance and culture was performed. DNA extraction and conventional PCR were performed in colonies compatibles with S. equi, the PCR products we...
Fielding CL, Pusterla N, Magdesian KG, Higgins JC, Meier CA.To characterize signalment, clinical and laboratory findings, treatment, and outcome in horses with rattlesnake envenomation in northern California. Methods: Retrospective case series. Methods: 58 client-owned horses evaluated for rattlesnake envenomation at 2 referral hospitals from 1992 to 2009. Methods: Records of horses with rattlesnake envenomation were reviewed, and data concerning signalment, clinical and laboratory findings, treatment, and outcome were collected. In addition, a rattlesnake-bite severity score (RBSS) was assigned to each horse. Variables were compared between horses tha...
Souto EPF, Maia LA, Neto EGM, Kommers GD, Junior FG, Riet-Correa F, Galiza GJN, Dantas AFM.The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) wa...
Davis TZ, Stegelmeier BL, Hall JO.Horses are very susceptible to chronic selenosis if grazed on seleniferous forages for a prolonged period. In this study, mane and tail samples from horses that exhibited classical hoof lesions of chronic selenosis were analyzed by inductively coupled plasma mass spectrometry for selenium (Se) content. The horses had grazed for 6 months, from approximately May 15 until November 15, each year for three grazing seasons in a pasture containing seleniferous forages and water sources with elevated Se concentrations. The segmented hair samples showed a cyclic pattern in Se concentrations in the mane...
Tscheschlok L, Venner M, Howard J.Failure of transfer of passive immunity (FTPI) in foals is associated with a risk of infection and death. The current diagnostic gold standard is quantification of immunoglobulins using radial immunodiffusion (IgG-RID). Routine diagnosis is often performed using semi-quantitative tests. Concentrations of serum electrophoretic gamma globulins (EGG) and total globulins may be useful to assess FTPI, but few studies have investigated their use. Objective: To assess agreement between IgG-RID and EGG and evaluate the accuracy of total globulin concentration to diagnose FTPI based on both IgG-RID and...
Yin X, Lin Y, Cai W, Wei P, Wang X.Equine infectious anemia virus (EIAV) is an important animal model for understanding the relationship between viral persistence and the host immune response during lentiviral infections. Comparison and analysis of the codon usage model between EIAV and its hosts is important for the comprehension of viral evolution. In our study, the codon usage pattern of EIAV was analyzed from the available 29 full-length EIAV genomes through multivariate statistical methods. Results: Effective number of codons (ENC) suggests that the codon usage among EIAV strains is slightly biased. The ENC-plot analysis d...
Lichtenstein DL, Craigo JK, Leroux C, Rushlow KE, Cook RF, Cook SJ, Issel CJ, Montelaro RC.The long terminal repeat (LTR) is reported to be one of the most variable portions of the equine infectious anemia virus (EIAV) genome. To date, however, no information is available on the effects of observed sequence variations on viral replication properties, despite a widespread assumption of the biological importance of EIAV LTR variation. EIAV LTR sequence variability is confined mostly to a small portion of the enhancer within the U3 segment of the LTR. Analysis of published EIAV LTR sequences revealed six different types of LTR based on the pattern of putative transcription factor motif...
Boyle AG, Boston RC, O'Shea K, Young S, Rankin SC.Streptococcus equi is the etiologic agent of a highly infectious upper respiratory disease of horses known as strangles. Bacterial culture methods and polymerase chain reaction (PCR) of nasopharyngeal washes and guttural pouch lavages are used routinely to test clinical and carrier animals for the presence of S. equi but no definitive or gold standard test method has been shown to be optimal. We hypothesized that (i) a flocked swab submerged in ten-fold serial dilution suspensions of S. equi prepared in 0.9% NaCl would detect more colony forming units (CFU) than a rayon swab when used to inocu...
Gruber J.Purified and concentrated Venezuelan equine encephalitis (VEE) virus derived from tissue cultures, rendered noninfectious by ionizing radiation with retention of in vitro serological activity, also retained a high level of immunogenicity. In mice, fluid vaccines afforded excellent protection against lethal challenge with homologous Trinidad strain VEE virus. A direct relationship was observed between concentration of vaccine or number of injections and survival. One intraperitoneal inoculation of undiluted vaccine protected essentially all mice challenged 21 days later with 100,000 mouse intra...
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...
Wolf D, Hermosilla C, Taubert A.Whilst anthelminthic resistance of small strongyles is well documented, anthelmintic failures against infections with Oxyuris equi have scarcely been published so far. We describe two cases of equine oxyurosis and the anthelminthic failure of macrocyclic lactones (moxidectin, ivermectin) resulting in persistent O. equi infections with continuous egg shedding. The horses were kept in two different herds in the federal state of Hessia, Germany. Herd A kept two geldings: an 8-year-old Welsh-Cob-Mix and a 7-year-old Haflinger. Herd B was composed of four animals: 2 Connemara-mares, 31 and 19 years...
Brosnahan MM, Al Abri MA, Brooks SA, Antczak DF, Osterrieder N.Equine herpesvirus type 1 (EHV-1)-induced myeloencephalopathy (EHM) is a neurologic disease of horses that represents one outcome of infection. The neurologic form of disease occurs in a subset of infected horses when virus-induced endothelial cell damage triggers vasculitis and subsequent ischemic insult to the central nervous system. EHM causes considerable animal suffering and economic loss for the horse industry. Virus polymorphisms have been previously associated with disease outcome but cannot fully explain why only some horses develop EHM. This study investigated the role of host geneti...
Ribeiro IB, Câmara AC, Bittencourt MV, Marçola TG, Paludo GR, Soto-Blanco B.This study aimed to determine whether asymptomatic horses naturally infected with Theileria equi retain infected erythrocytes in the spleen and whether the presence of the hemoparasite in this organ is associated with parasitemia. We collected samples from 25 adult horses without clinical signs of any disease. From each animal, we collected whole blood samples from the jugular vein and a splenic puncture blood sample. All samples were submited to blood cell counts and detection of Theileria or Babesia. DNA extraction and PCR were performed in all samples for identification of piroplasm infecti...
Lee SK, Lee I.Equine herpesvirus (EHV) 2 and equine herpesvirus 5 (EHV-5) have been getting attention as potential causative pathogens of reproductive disorders in horses. Equine herpesviruses 2 and 5 are widespread among horses and have been detected in various samples including nasal swabs, blood, and ocular swabs. However, the detection of these pathogens in genital swabs has not been determined. The aims of this study were to determine the positive rate of EHV-2 and EHV-5 DNA in genital swabs taken from clinically normal mares and to define the genetic diversity of these EHV-2 and EHV-5 DNA sequences by...
Cocco P, Satta G, D'Andrea I, Nonne T, Udas G, Zucca M, Mannetje A', Becker N, Sanjosé Sd, Foretova L, Staines A, Maynadié M, Nieters A, Brennan P....We explored the risk of lymphoma and its most prevalent subtypes associated with occupational contact with livestock, and whether risk was modified by age at first contact, in 2,348 incident lymphoma cases and 2,462 controls who participated in the EPILYMPH case-control study. A detailed occupational history was collected in cases and controls, including working in a livestock farm, species of livestock, its approximate number and circumstances of contact. For each disease outcome, and each type of livestock, odds ratios (OR) and their 95% confidence intervals (95% CI) were calculated using un...
Marchi PR, Rawlings P, Burroughs JN, Wellby M, Mertens PP, Mellor PS, Wade-Evans AM.Purified African horse sickness virus (AHSV) was fed, as part of a blood meal, to adult females from a susceptible colony of Culicoides variipennis, established in the insectories at the Institute for Animal Health, Pirbright Laboratory, UK. The meal consisted of heparinized blood obtained from ovine, bovine, equine (horse and donkey) or canine sources spiked with AHSV serotype 9 (AHSV9). The infectivity levels observed for C. variipennis varied significantly, according to the source of the blood sample. Comparison of the protein profiles obtained from AHSV9 incubated with the individual serum...
Brankston G, Greer AL, Marshall Q, Lang B, Moore K, Hodgins D, Hennessey JTG, Beeler-Marfisi J.Ambient pollution is associated with the development and exacerbation of human asthma, but whether air pollution exposure is associated with lower airway inflammation in horses has not been fully evaluated. The Air Quality Health Index (AQHI) is an online tool used by asthmatic Ontarians to modify their outdoor activity when ambient pollution is high. A single AQHI value, falling on a scale from 1 to 10, is calculated from measurements of fine particulate matter (PM), nitrogen dioxide (NO), and ozone (O). Increased AQHI values predict an increased risk for presenting to a health care provider ...
Boysen C, Davis EG, Beard LA, Lubbers BV, Raghavan RK.Kansas witnessed an unprecedented outbreak in Corynebacterium pseudotuberculosis infection among horses, a disease commonly referred to as pigeon fever during fall 2012. Bayesian geostatistical models were developed to identify key environmental and climatic risk factors associated with C. pseudotuberculosis infection in horses. Positive infection status among horses (cases) was determined by positive test results for characteristic abscess formation, positive bacterial culture on purulent material obtained from a lanced abscess (n = 82), or positive serologic evidence of exposure to organism ...
Mendez D, Büttner P, Speare R.A cross-sectional study of private veterinarians providing equine services in Queensland. Results: The study revealed that a majority of veterinarians would support the introduction of a Hendra virus (HeV) vaccine. Moreover, almost half of the respondents intended to make vaccination a prerequisite to horse patient presentation. However, participants also responded that a vaccine would not reduce the risk sufficiently to cease or downgrade their HeV management plan and infection control measures. Conclusions: When devising promoting and marketing campaigns, government agencies and manufacturer...
Figueiredo AS, Lampe E, de Albuquerque PPLF, Chalhoub FLL, de Filippis AMB, Villar LM, Cruz OG, Pinto MA, de Oliveira JM.Among the hepacivirus species recently described, the non-primate hepacivirus/hepacivirus A found in horses and donkeys is closely related to the human hepatitis C virus (HCV). Therefore, the equine is an attractive surrogate large animal model for the study of HCV therapy, pathogenesis and prophylaxis. Despite global efforts, epidemiological and genetic studies have not elucidated the risk factors, virus distribution or genetic variability of the hepacivirus A, which are also important issues for the equine welfare. Little information about this background scenery is available in Brazil. The ...
McCartan CG, Russell MM, Wood JL, Mumford JA.An outbreak of equine herpesvirus-1 (EHV-1) occurred on a large stud farm with 133 mares, 54 foals and four stallions, and at least 85 mares, 22 foals and three stallions were infected. Clinical disease was observed in 16 mares, two stallions and 13 foals and the predominant clinical signs were scrotal oedema, ataxia and loss of libido in the stallions, ataxia and recumbency in the mares and uveitis and nasal discharge in the foals, although pneumonia and colic with intussusception were also recorded at autopsy. Neurological disease was more common in the mares nursing foals (12 of 38 infected...
Mullen KR, Rivera BN, Tidwell LG, Ivanek R, Anderson KA, Ainsworth DM.Studies of neonatal health risks of unconventional natural gas development (UNGD) have not included comprehensive assessments of environmental chemical exposures. We investigated a clustering of dysphagic cases in neonatal foals born between 2014 and 2016 in an area of active UNGD in Pennsylvania (PA),USA. We evaluated equine biological data and environmental exposures on the affected PA farm and an unaffected New York (NY) farm owned by the same proprietor. Dams either spent their entire gestation on one farm or moved to the other farm in late gestation. Over the 21-month study period, physic...
Hayama Y, Kobayashi S, Nishida T, Muroga N, Tsutsui T.An equine infectious anemia (EIA) transmission model was developed by constructing a network structure of horse movement patterns in a non-racehorse population. This model was then used to evaluate the effectiveness and efficiency of several EIA surveillance strategies. Because EIA had not been detected in Japan since 1993, it was appropriate to review the current surveillance strategy, which aims to eradicate EIA by intensive testing, and to consider alternative strategies suitable for the current EIA status in Japan. The non-racehorse population was divided into four sectors based on horse u...
