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.
Tesena P, Yingchutrakul Y, Roytrakul S, Taylor J, Angkanaporn K, Wongtawan T.Equine squamous gastric disease (ESGD) is a very common disorder but an accurate and practical screening technique for detecting ESGD is currently lacking. Objective: To identify serum protein markers to detect ESGD using electrophoresis and mass spectrometry. Methods: Proteomic analysis and bioinformatics. Methods: ESGD was diagnosed using gastroscopy in 30 horses. Gastric ulceration was categorised into three groups: normal, mild/moderate and severe ESGD. Pooled sera from each group were compared using 1D electrophoresis and mass spectrometry. The candidate proteins for ESGD markers were sel...
Wilkołek P, Szczepanik M, Sitkowski W, Adamek Ł, Pluta M, Taszkun I, Gołyński M.New techniques in equine veterinary allergy testing include multiple allergen simultaneous tests (MASTs) that cover insect bite hypersensitivity (IBH), respiratory and atopic allergic diseases. The in vivo intradermal test (IDT) method is one of the most widely used techniques in veterinary practice, but recently, in vitro methods have been introduced as possible alternatives. This study was designed to assess the correlation between IDTs and MASTs based on IgE determination in serum. The study was performed on Malopolski breed horses with IBH (n = 26). IDTs were performed, and allergen-spe...
Sánchez-Guerrero MJ, Solé M, Azor PJ, Sölkner J, Valera M.Vitiligo and melanoma are relatively common disorders in grey Pura Raza Español horses and other horse breeds with grey-coloured coats. Objective: To determine the breed prevalence, environmental risks factors and estimate the genetic parameters for vitiligo and melanoma in Pura Raza Español horses. Methods: Retrospective cohort study. Methods: We analysed data from a large worldwide population of Pura Raza Español horses. The database included the vitiligo and melanoma scores, on either a four- or six-point linear scale, of 11,436 horses. Genetic parameters were estimated using a Bayesian ...
Knickelbein KE, Luethy D, Thomasy SM, Reilly C, Strom AR, Lassaline ME.(a) To evaluate the epidemiology of equine eosinophilic keratoconjunctivitis (EK) in the western United States, (b) to ascertain the efficacy of keratectomy and diamond burr debridement vs medical management alone, (c) to determine the efficacy of various medical therapies, and (d) to further characterize the histopathologic findings of the disease in horses. Methods: Twenty-nine horses (47 eyes) diagnosed with EK from 1993 to 2017. Methods: Retrospective medical record review; owner questionnaire. Results: Average age of presentation was 11 ± 4 years. Warmbloods were significantly overrep...
Bino E, Lauková A, Ščerbová J, Kubašová I, Kandričáková A, Strompfová V, Miltko R, Belzecki G.The intestinal microbiota has enormous impact on the health and performance of horses. Staphylococci belong in the phylum Firmicutes, and their occurrence, especially of methicillin-resistant strains and species, has been reported in horses previously. Moreover, biofilm formation is one of the virulence factors; it has been not completely studied in fecal coagulase-negative staphylococci (CoNS) from horses. Therefore, this study was focused on biofilm formation by various species of fecal CoNS from horses because it has been never reported before. In addition, their antibiotic profile was test...
Tarancón I, Leiva M, Jose-Cunilleras E, Ríos J, Peña T.To describe ocular findings associated with Rhodococcus equi bronchopneumonia in foals, and to determine whether severity of the ocular lesions is related with outcome. Methods: Foals diagnosed with R equi infection at the VTH-UAB from January 2002 to December 2017. Methods: Rhodococcus equi infection was diagnosed by means of clinical signs, radiographic/ultrasonographic findings, and/or positive culture. In all the foals, a complete ophthalmic examination by a boarded ophthalmologist was performed and ocular signs were recorded and graded (0-4). Results: Thirty-nine foals were included in t...
Müntener C, Kupper J, Naegeli H, Gassner B.A total of 306 reports of adverse reactions to veterinary medicinal products were received during the year 2017 representing an increase of 21% compared to the previous year. The majority of these reports described reactions concerning companion animals (180 dogs and 59 cats) as well as cattle (38 reports) and horses (14 reports). Most of the reported reactions were linked to the use of antiparasitics (158 reports), hormone products (30 reports) and anti-inflammatory products (25 reports). 40 reports were generated from consultations with Tox Info Suisse in Zürich and mainly involved the ex...
González-Medina S, Montesso F, Chang YM, Hyde C, Piercy RJ.Several pasture management strategies have been proposed to avoid hypoglycin A (HGA) intoxication in horses, but their efficacy has never been investigated. Objective: To evaluate the effect of mowing and herbicidal spraying on HGA content of sycamore seedlings and the presence of HGA in seeds and seedlings processed within haylage and silage. Methods: Experimental study. Methods: Groups of seedlings were mowed (n = 6), sprayed with a dimethylamine-based (n = 2) or a picolinic acid-based herbicide (n = 1). Seedlings were collected before intervention, and at 48 h, 1 and 2 weeks after. ...
Sperl C, Gerber V, Drießlein D, Klima A, Becher AM.Respiratory signs or more specifically severe equine asthma (SEA) is in some studies reported to be associated with decreased strongyle egg shedding. This association can be reproduced in a larger population of unrelated horses. The owners of 209 horses, on seven farms in Bavaria, were interviewed using, an in prior studies validated questionnaire. Horses were categorized into classes of the horse owner assessed respiratory signs index (HOARSI 1-4, unaffected to severely affected). In total, 1,035 fecal samples were analyzed between March 2011 and September 2014 using a modified McMaster proce...
Pratscher B, Hainisch EK, Sykora S, Brandt S, Jindra C.There is a large body of evidence supporting bovine papillomavirus types 1 and 2 (BPV1; BPV2) as aetiological agents of equine sarcoids. However, there is conflicting data regarding BPV1/2 infection in sarcoid-free equids. Objective: Data obtained between 2007 and 2017 by BPV1/2 screening of sarcoids and nonsarcoid tumours vs. samples from healthy equids are presented to help clarify this issue. Methods: Cross-sectional study. Methods: Tumour material obtained from horses, donkeys and mules with confirmed sarcoids (n = 130), suspected sarcoids (n = 120), or nonsarcoid lesions (n = 70), s...
Divers TJ, Chang YF, Irby NL, Smith JL, Carter CN.North American horses are commonly exposed to Leptospira organisms. Leptospira Bratislava is the most common infecting serovar but this serovar has not been confirmed to cause clinical disease in North American horses. Leptospira Pomona type kennewicki is responsible for most of the clinical diseases (leptospirosis) in North American horses. Leptospirosis is most commonly associated with diseases of the placenta and fetus, the kidneys and the eyes in horses. In-utero infections in pregnant mares may result in abortion, neonatal illness or birth of an antibody positive healthy foal. Acute renal...
Slivinska K, Karbowiak G, Gawor J, Wróblewski Z, Jaworski Z, Jastrzębska E, Demeshkant V.The influence of internal and external parasites on the health of Polish konik horses housed in different types of management strategies in Poland is discussed. This study includes consolidated data of different authors from the past 50 years, supplemented by results of more recent research. A total of 38 species of helminths (i.e., 37 Nematoda and one Cestoda) and five Diptera species were recorded from the horses. Protozoan parasites, Cryptosporidium spp. and Theileria equi, and the Rickettsiales, Anaplasma phagocytophilum, were observed for the first time in Poland.
Peloso JG, Cohen ND, Vogler JB, Marquis PA, Hilt L.OBJECTIVE To compare bony changes of the third metacarpal bone (MC3) of Thoroughbred racehorse cadavers with (cases) or without (controls) catastrophic condylar fracture by use of standing MRI. SAMPLE 140 forelimbs from 26 case horses (both forelimbs) and 88 control horses (single forelimb). PROCEDURES Bone marrow lesions (BMLs), identified as a decrease in T1-weighted (T1W) signal and increases in T2*-weighted (T2*W) and short tau inversion recovery (STIR) signals, and dense bone volume percentage (DBVP), identified as decreases in T1W, T2*W, and STIR signals, in the distopalmar aspect of MC3...
Public healthJanuary 25, 2019
Volume 168 67-75 doi: 10.1016/j.puhe.2018.11.023
Meredith L, Thomson R, Ekman R, Kovaceva J, Ekbrand H, Bálint A.Horse riding is a popular activity but has also been found to lead to many injuries and even fatalities. No reduction in the numbers of those being admitted to hospital for equestrian-related injuries have been seen in Sweden in recent years. The aim of this work was to examine injuries, fatalities, and predictors of fatalities in equestrian-related activities and to investigate the cost of these injuries to the public health system. Methods: The study is a retrospective analysis of hospital data. Methods: National Swedish hospital and mortality registers were retrospectively examined, inclusi...
Rosanowski SM, Carpenter TE, Adamson D, Rogers CW, Pearce P, Burns M, Cogger N.Equine influenza (EI) is an infectious respiratory disease of horses that has never been reported in New Zealand (NZ). However, the 2007 EI outbreak in Australia, previously EI free, spurred the NZ government and stakeholders into evaluating alternative EI control strategies in order to economically justify any future decision to eradicate or manage EI. To build on the policy debate, this paper presents an epinomic (epidemiologic and economic) modelling approach to evaluate alternative control strategies. An epidemiologic model to determine how alternative EI control strategies influence the d...
Equine infectious anaemia (EIA) is a blood borne disease that is listed among the notifiable diseases of the World Organisation for Animal Health (OIE). EIA is also regulated by the OIE for the international trading provisions and is generally subject to control programmes. Since 2011, Italy has been conducting a surveillance plan based on a three-tier diagnostic system, using a serological ELISA as screening test, an agar gel immunodiffusion test (AGIDT) as a confirmatory method, and an immunoblot (IB) as an alternative confirmatory assay for discordant results between the first two tests. As...
Noiva R, Ruivo P, de Carvalho LM, Fonseca C, Fevereiro M, Carvalho P, Orge L, Monteiro M, Peleteiro MC.Halicephalobus gingivalis is a small saprophytic rhabditid nematode, represented only by females with a typical rhabditoid oesophagus and one egg in the uterus, capable of infecting vertebrates. This opportunistic parasite present in the soil, manure and decaying humus, is thought to penetrate through previous injuries to the mouth, eyes and skin of horses and migrate to various organs. The brain is one such organ, where the females lay their eggs, leading to malacia and causing a sudden onset of neurological signs, such as anorexia, ataxia, urinary incontinence, blindness, decreased menace an...
Martins LC, Silva EVPD, Casseb LMN, Silva SPD, Cruz ACR, Pantoja JAS, Medeiros DBA, Martins Filho AJ, Cruz EDRMD, Araújo MTF, Cardoso JF....Serological evidence of West Nile virus (WNV) infection has been reported in different regions of Brazil from equine and human hosts but the virus had never been isolated in the country. Objective: We sought to identify the viral etiology of equine encephalitis in Espírito Santo state. Methods: We performed viral culture in C6/36 cells, molecular detection of WNV genome, histopathology and immunohistochemistry from horse cerebral tissue. We also carried out sequencing, phylogenetic analysis and molecular clock. Results: Histopathologic analysis from horse cerebral tissue showed injury related...
Pollard D, Wylie CE, Newton JR, Verheyen KLP.Previous robust epidemiological studies of equine laminitis have utilised only veterinary-diagnosed episodes of disease, potentially underestimating true disease frequency. Objective: To estimate the incidence of, and describe clinical signs associated with, owner-reported active laminitis in horses/ponies, using both veterinary-diagnosed and nonveterinary-diagnosed episodes. Methods: Prospective cohort. Methods: Data were collected from horse/pony owners in Great Britain between August 2014 and December 2016 using a web-based application. The incidence of owner-reported laminitis was estimate...
Wang J, Liu J, Yang J, Wang X, Li Z, Jianlin X, Li X, Xiang Q, Li Y, Liu Z, Luo J, Guan G, Yin H.Equine piroplasmosis, caused by Theileria equi and Babesia caballi, is an economically important tick-borne disease worldwide. In the current study, 242 blood samples were randomly collected from horses in Zhangye city of Gansu province, China. The presence and genetic diversity of piroplasms were evaluated with a nested PCR assay, gene sequencing and phylogenetic analysis. The results showed that seventy-five (31.0%) samples were positive for piroplasms. Sequences analysis showed that seventy-three (30.2%) were positive for T. equi, and seven (2.9%) for B. caballi, five of which (2.1%) were i...
de Lagarde M, Larrieu C, Praud K, Schouler C, Doublet B, Sallé G, Fairbrother JM, Arsenault J.Although antimicrobial resistance is increasingly common in equine medicine, molecular and epidemiological data remains scarce. Objective: We estimated the prevalence of, and risk factors for, shedding of multidrug resistant (MDR), extended spectrum β-lactamase (ESBL)-producing, and AmpC β-lactamase-producing, or some combination of these in Escherichia coli in horses in France. We characterized ESBL/AmpC isolates for antimicrobial susceptibility and the presence of virulence and ESBL/AmpC-associated resistance genes. Methods: Fecal samples from healthy adult horses at 41 premises were colle...
Francesca Martelli, Sue Kidd and Joanna Lawes of the APHA discuss surveillance findings relating to Salmonella isolates from horses, and also the antimicrobial resistance patterns being seen.
Zhou P, Luo A, Xiao X, Hu X, Shen D, Li J, Wu X, Xian X, Wei C, Fu C, Zhang G, Sun L, Li S.Currently, Canine influenza virus (CIV) H3N2 is continuously circulating in dog populations in China, Korea, and the United States (US). Both influenza SA-α-2,3-Gal and SA-α-2,6-Gal receptors have been observed in the respiratory tracts of both horses and dogs. Hence, the increasing number of CIV H3N2 cases in the world indicates a potential risk for transspecies transmission to horses with dog exposure. Here, a seroepidemiological survey of CIV H3N2 infections in horses was conducted using hemagglutination inhibition (HI), microneutralization (MN) and the chicken embryo neutralization test ...
Kalashnikov VV, Zajcev AM, Atroshchenko MM, Miroshnikov SA, Zavyalov OA, Frolov AN, Skalny AV.The objective of the present study was assessment of gender differences in hair trace element content in English Thoroughbred horses (North Caucasus, Russia) using ICP-DRC-MS and calculation of the reference values. Trace element content in mane hair of 190 stallions and 94 mares (3-7 years old) bred in North Caucasus (Russia) was assessed using inductively coupled plasma mass spectrometry. Mane hair Co, Cr, Mn, Li, Si, and Sr levels in mares exceeded those in stallions by 77%, 63%, 64%, 42%, 39%, and 64%, respectively. Hair Fe and Si content was nearly twofold higher in female horses as comp...
Milwid RM, O'Sullivan TL, Poljak Z, Laskowski M, Greer AL.Contact networks can be used to assess disease spread potential within a population. However, the data required to generate the networks can be challenging to collect. One method of collecting this type of data is by using radio-frequency identification (RFID) tags. The OpenBeacon RFID system generally consists of tags and readers. Communicating tags should be within 10m of the readers, which are powered by an external power source. The readers are challenging to implement in agricultural settings due to the lack of a power source and the large area needed to be covered. OpenBeacon firmware wa...
Gianino GM, Valberg SJ, Perumbakkam S, Henry ML, Gardner K, Penedo C, Finno CJ.Immune-mediated myositis (IMM) in American Quarter Horses (QHs) causes acute muscle atrophy and lymphocytic infiltration of myofibers. Recently, an E321G mutation in a highly conserved region of the myosin heavy chain 1 (MYH1) gene was associated with susceptibility to IMM and nonexertional rhabdomyolysis. Objective: To estimate prevalence of the E321G MYH1 variant in the QH breed and performance subgroups. Methods: Three-hundred seven elite performance QHs and 146 random registered QH controls. Methods: Prospective genetic survey. Elite QHs from barrel racing, cutting, halter, racing, reining...
Kecerova Z, Cizek A, Nyc O, Krutova M.Clostridium difficile has been recovered from the faeces of several animal species as well as horses. Between April 2015 and October 2016, 213 samples of faeces from non-hospitalized (n = 138) and hospitalized horses (n = 75) were investigated and eighteen C. difficile isolates were cultured using an enrichment method. Sixteen C. difficile positive samples were identified from hospitalised horses (p < 0.01). Molecular typing revealed seven ribotypes and sequence types (RT033/ST11 n = 8, 44.4%; RT081/ST9 n = 4, 22.2%; RT009/ST3 n = 2, 11.1%; RT003/ST12 n = 1, 5.6%;...
Seo MG, Ouh IO, Choi E, Kwon OD, Kwak D.The identification and characterization of pathogenic and zoonotic tick-borne diseases like granulocytic anaplasmosis are essential for developing effective control programs. The differential diagnosis of pathogenic Anaplasma phagocytophilum and non-pathogenic A. phagocytophilum-like Anaplasma spp. is important for implementing effective treatment from control programs. The objective of the present study was to investigate the prevalence of Anaplasma spp. in horses in Korea by nucleotide sequencing and restriction enzyme fragment length polymorphism assay. Of the 627 horses included in the stu...
Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA.The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfa...
Barros SC, Ramos F, Fagulha T, Duarte M, Henriques M, Luís T, Fevereiro M.The circulation of West Nile virus in Portugal was assessed by serological surveys conducted during 2004-2010 in horses and birds. The detection of WNV antibodies in both species in all the years covered by the study as well as the presence of anti-WNV IgM in symptomatic horses that had not traveled outside the country, support the notion that WNV circulates in Portugal.
Miller JE, Mann S, Fettelschoss-Gabriel A, Wagner B.Culicoides hypersensitivity (CH), an intensely pruritic and seasonal allergic dermatitis, is a common allergic disease affecting horses worldwide. Currently, there is no validated clinical scoring system for the quantification of clinical signs associated with CH. Objective: To (i) determine the best cut-off point of three scoring systems, (ii) test the accuracy of each system when compared to the clinical diagnosis of an experienced veterinarian and (iii) assess agreement between systems. Methods: Icelandic horses (n = 20); eight with CH and 12 unaffected, from a research herd receiving no ...
Love S, Duncan JL.Groups of animals of different ages and experience of previous parasite exposure were allowed to graze a single pasture for 5 weeks in autumn (7 October to 11 November). There was evidence that previous exposure modified cyathostome development, as acquired burdens in foals which had previously grazed were smaller and developed more slowly than those of helminth-naive animals of the same age. The burdens acquired by yearling and adult ponies were of a similar size to those of the previously grazed foals, but the incidence of arrested development was higher in the younger groups of foals and ye...
Dunowska M.Equid herpesvirus (EHV) type 1 is a common pathogen of horses with worldwide distribution. Infection with EHV-1 can be subclinical, or can result in sociologically and economically important outcomes such as abortion, neonatal death or neurological disease. The perceived recent increase in the reported cases of EHV-1 neurological disease in the United States of America and Europe over the past decade has caused concerns amongst veterinarians and horse owners worldwide. This review provides an update on the recent developments in our understanding of the pathogenesis and epidemiology of EHV-1 a...
Mellor DJ, Love S, Gettinby G, Reid SW.The size, composition and distribution of the equine population of Scotland and the five northernmost counties in England were estimated through a series of mailed questionnaire surveys of sentinel veterinary practices and horse owners. An estimated 96,622 equine animals were kept by an estimated 26,114 owners. The mean (sd) age of the population was 11.0 (7.5) years (range one month to 37 years). Thoroughbred or thoroughbred-cross animals were the most numerous, constituting 30 per cent (95 per cent confidence interval 27 to 33 per cent) of the total population. The ratio of males:females was...
Olguin Perglione C, Golemba MD, Torres C, Barrandeguy M.Equine influenza virus (EIV) is considered the most important respiratory pathogen of horses as outbreaks of the disease lead to substantial economic losses. The H3N8 EIV has caused respiratory disease in horses across the world, including South American countries. Nucleotide and deduced amino acid sequences for the complete haemagglutinin gene of the H3N8 EIV detected in South America since 1963 were analyzed. Phylogenetic and Bayesian coalescent analyses were carried out to study the origin, the time of the most recent common ancestors (tMRCA), the demographic and the phylogeographic pattern...
Dubey JP, Venturini MC, Venturini L, McKinney J, Pecoraro M.Sera from 76 horses from Argentina were examined for antibodies to Sarcocystis neurona, Toxoplasma gondii and Neospora caninum. Antibodies to S. neurona were found in 27 (35.5%) of 76 horses using immunoblots with culture derived merozoites as antigen. Antibodies to T. gondii were found in 10 (13.1%) of 76 horses by using the modified agglutination test with formalin-fixed tachyzoites and mercaptoethanol; titers were 1:25 (two horses), 1:50 (six horses), 1:100 (two horses), and 1:200 (one horse). Antibodies to N. caninum were not found in any of the 76 horses by the use of N. caninum agglutina...
Kaiser-Thom S, Hilty M, Axiak S, Gerber V.Equine pastern dermatitis (EPD), a multifactorial syndrome, manifests as skin lesions of variable severity in the pastern area. Despite the widespread use of antibacterial therapy for treating this condition, little is known about the contributing bacteria. Objective: To investigate the bacterial skin microbiota in EPD-affected and unaffected (control) pasterns. Methods: Case-control study with 80 client-owned horses; each with at least one EPD-affected and one control pastern. Methods: Horses were grouped by the form of EPD (mild, exudative or proliferative), the assigned severity grade and t...
Cirak VY, Hermosilla C, Bauer C.Quantitative faecal and post-mortem examinations of 16 ponies, 1 to 2 1/2 years of age, originating from 3 farms in northern Germany were performed in February 1995 to determine the prevalence and intensity of gastrointestinal parasites in these animals. A total of 33 species of metazoan parasites was recovered: three tapeworm species (Anoplocephala perfoliata, A. magna, Paranoplocephala mamillana), Strongylus vulgaris, S. edentatus, small strongyles (including four Triodontophorus spp., Craterostomum acuticaudatum and 19 cyathostome species), Oxyuris equi, Parascaris equorum, Habronema majus ...
Pagamjav O, Kobayashi K, Murakami H, Tabata Y, Miura Y, Boldbaatar B, Sentsui H.Three hundred sera were collected from horses in various parts of Mongolia in 2007 and seroepidemiological surveys for several equine viruses performed on them. Equid herpesvirus 1 and equine rhinitis A virus were prevalent, and equine arteritis virus and equid herpesvirus 3 were detected over a wide area though their rates of antibody-positivity were not high. Equine infectious anemia was distributed locally. The rates of horses antibody-positive for Japanese encephalitis virus and equine influenza virus were low, but these were detected. Bovine coronavirus antibodies were detected at a high ...
PLUMMER G.Experiments involving the intranasal inoculation of monkeys, rabbits and guinea pigs with an equine respiratory virus were carried out. The animals were killed at various intervals after inoculation and attempts made to isolate virus in tissue culture from extracts of homogenized tissues and organs. All three species were susceptible, virus reproduction occurring in the respiratory tract and associated lymph glands. Of the three species virus was least readily isolated from the guinea pig tissues. There was a viraemia in monkeys and rabbits, but virus was less readily detected in the blood of ...
Ellis-Iversen J, Pritchard GC, Wooldridge M, Nielen M.Campylobacter jejuni and C. coli are the most prevalent causes of bacterial diarrhoea in most of the Western World. In Great Britain, the source remains unknown for the majority of cases, though poultry is considered the main source of infection. Molecular typing methods identify cattle as a potential source of a proportion of the non-source-attributed cases, mainly through direct contact, environmental contamination or milk, but little is known about the epidemiology of Campylobacter in cattle. A cross-sectional study was undertaken on young cattle 3-17 months of age on 56 cattle farms in Eng...
Hawkins JA, Adams WV, Wilson BH, Issel CJ, Roth EE.The mechanical transmission of equine infectious anemia (EIA) virus by Tabanus fuscicostatus was investigated. In 1 of 7 transmission trials, a single horsefly transmitted EIA virus from an acutely infected pony to a susceptible pony. Groups of horseflies isolated for 3, 10, or 30 minutes before refeeding transmitted EIA virus, whereas those isolated for 4 or 24 hours did not. Data from field studies indicate that the home range or flight distance of horseflies may exceed 4 miles. That information together with our observations suggest that segregation of infected horses (usually defined as at...
Castillo-Olivares J, Mansfield KL, Phipps LP, Johnson N, Tearle J, Fooks AR.West Nile virus (WNV) has re-emerged as an important pathogen for humans and horses, which are considered to be incidental 'dead-end' hosts. We have demonstrated that horses are susceptible to experimental infection with WNV and that horses infected with either WNV lineage 1 or lineage 2 elicit a similar antibody profile in serum samples. These data suggest that virus-neutralizing antibody responses persist for longer than WNV-specific IgM levels in serum and that there are not any notable differences in the antibody profile following experimental infection of horses with either WNV lineage 1 ...
Ribeiro MG, Seki I, Yasuoka K, Kakuda T, Sasaki Y, Tsubaki S, Takai S.We investigated the prevalence of virulent Rhodococcus equi in clinical isolates from 41 foals (19 sporadic and seven endemic cases) in Brazil between 1991 and 2003. Of the 41 virulent isolates, six contained an 85-kb type I plasmid, 33 contained an 87-kb type I plasmid, both of which have been found in isolates from the Americas, and the remaining two contained a new variant, which did not display the EcoRI, EcoT22I and BamHI digestion patterns of the 11 representative plasmids already reported (85-kb types I-IV; 87-kb types I and II; 90-kb types I-V). We tentatively designated the new varian...
Grinberg A, Pomroy WE, Carslake HB, Shi Y, Gibson IR, Drayton BM.To assess the occurrence of Cryptosporidium oocysts in faecal specimens from foals, and investigate an outbreak of neonatal cryptosporidiosis in foals revealed in the course of the study. Methods: Faecal specimens from foals received by a diagnostic veterinary laboratory in New Zealand between 2006 and 2007 were submitted to Massey University and tested microscopically for the presence of Cryptosporidium oocysts. The Cryptosporidium isolates in the oocyst-positive specimens were genetically identified to species level. In addition, specimen submission data from the participating laboratory for...
Anstey S, Lizárraga D, Nyari S, Chalmers G, Carrick J, Chicken C, Jenkins C, Perkins N, Timms P, Jelocnik M.Late-term foal loss due to the traditional avian pathogen Chlamydia psittaci recently emerged as a threat to the Australian Thoroughbred industry. A longitudinal study of 14 stud farms was undertaken to better understand C. psittaci infection in pregnant mares and their foals by evaluating C. psittaci prevalence, equine herpesvirus-1 (EHV-1) co-infection, avian reservoirs, and potential risk factors. Mucosal swabs taken from 228 healthy pregnant mares and their foals were tested for C. psittaci and EHV-1 using species-specific qPCR assays. No foal loss was recorded due to either pathogen, and ...
McBrearty KA, Murray A, Dunowska M.To determine which viruses circulate among selected populations of New Zealand horses and whether or not viral infections were associated with development of respiratory disease. Methods: Nasal swabs were collected from 33 healthy horses and 52 horses with respiratory disease and tested by virus isolation and/or PCR for the presence of equine herpesviruses (EHV) and equine rhinitis viruses. Results: Herpesviruses were the only viruses detected in nasal swab samples. When both the results of nasal swab PCR and virus isolation were considered together, a total of 41/52 (79%) horses with respirat...
Cohen ND, Smith KE, Ficht TA, Takai S, Libal MC, West BR, DelRosario LS, Becu T, Leadon DP, Buckley T, Chaffin MK, Martens RJ.To compare isolates of Rhodococcus equi on the basis of geographic source and virulence status by use of pulsed-field gel electrophoresis (PFGE). Methods: 290 isolates of R equi (218 virulent isolates from foals and 72 avirulent isolates from feces, soil, and respiratory tract samples) obtained between 1985 and 2000 from horses and horse farms from 4 countries. Methods: DNA from isolates was digested with the restriction enzyme Asel and tested by use of PFGE. Products were analyzed for similarities in banding patterns by use of dendrograms. A similarity matrix was constructed for isolates, and...
Rosenthal FS, Gruntman A, Couetil LL.Measurements of total, respirable, and real-time airborne particulate were obtained in 12 horse barns in summer and winter. Respirable and total particulate concentrations were measured gravimetrically; real-time particulate was measured with an aerosol photometer. Total particulate (TP) ranged from nondetectable (ND) to 2.1 mg/m3 and from ND to 1.2 mg/m3 for winter and summer sampling, respectively. Respirable particulate (RP) ranged from ND to 0.2 mg/m3 and from ND to 0.7 mg/m3 for winter and summer measurements, respectively. The mean respirable fraction of particulate for summer and winter...
Carossino M, Barrandeguy ME, Erol E, Li Y, Balasuriya UBR.Equine rotavirus A (ERVA) is the leading cause of diarrhea in neonatal foals and has a negative impact on equine breeding enterprises worldwide. Among ERVA strains infecting foals, the genotypes G3P[12] and G14P[12] are the most prevalent, while infections by strains with other genomic arrangements are infrequent. The identification of circulating strains of ERVA is critical for diagnostic and surveillance purposes, as well as to understand their molecular epidemiology. Current genotyping methods available for ERVA and rotaviruses affecting other animal species rely on Sanger sequencing and ar...
Döpfer D, Kerssens CM, Meijer YG, Boersema JH, Eysker M.Faeces of 484 horses were sampled twice with an interval of 6 weeks while anthelmintic therapy was halted. Faecal eggs counts revealed that 267 (55.2%) horses had consistently low numbers of eggs per gram faeces (EPG) (EPG 100). Horses with consistently high EPGs were more often mares with access to pasture, aged less than 6 or more than 23 years, that were dewormed at intervals longer than 6 months, and were treated for the last time more than 3 months before the start of the study. Horses with consistently low EPGs were more often male horses with no or limited access to pasture, that were ...
Larsen ML, Ritz C, Petersen SL, Nielsen MK.Ivermectin resistance has recently been described in Parascaris equorum and there have been reports from several countries of a shortened egg reappearance period (ERP) following ivermectin treatment for cyathostomins. This study was aimed at determining the efficacy of ivermectin in treating cyathostomins and P. equorum in Danish horses. A total of 196 animals were selected from 52 farms, all of which were using a selective anthelmintic treatment strategy. ERP was investigated with weekly samples from 96 horses from nine farms. Horses were treated with ivermectin oral paste by their owners at ...