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.
CASALS J.A study by hemagglutination-inhibition test showed that 19 strains of eastern equine encephalitis virus grouped themselves in two main types, which have been designated North American and South American. The former consists of ten strains from the eastern half of the United States, from Massachusetts to Florida; Jamaica, the Dominican Republic, and, subject to confirmation, Thailand. The South American type comprises nine strains from Panama, Trinidad, British Guiana, Brazil, and Argentina. The strains were isolated from different natural hosts over a period of 30 years.
Marois P, Pavilanis V, Boudreault A, Di Franco E.The clinical diagnosis of equine influenza was first based on the spectacular contagiousness of the disease, the general clinical resemblances to human influenza and the almost complete absence of complications usually observed in infectious viral arteritis, viral rhinopneumonitis or in other respiratory infections of the horses. The specific viral etiology of the epizootic was ascertained through the isolation of a type A influenza virus and further substantiated by evaluation of the immunological response of the sick horses, as demonstrated by complement fixation and hemagglutination-inhibit...
BOYD WL, BOYD JW.Boyd, William L. (Ohio State University, Columbus) and Josephine W. Boyd. Viability of coliform bacteria in antarctic soil. J. Bacteriol. 85:1121-1123. 1963.-The distribution of coliform bacteria in soils of Ross Island and the nearby mainland was studied. None was found in almost all of the samples collected, including some from the Adelie penguin rookeries at Cape Royds and Cape Crozier and in soil at the McMurdo Base which had been recently contaminated by human sewage. Samples of pony manure left from previous expeditions were also negative, with one exception where Escherichia coli were p...
Jones SL, Valenzisi A, Sontakke S, Sprayberry KA, Maggi R, Hegarty B, Breitschwerdt E.Effusive, fibrinous pericarditis is an uncommon disease entity in horses. In 2001, pericarditis occurred in conjunction with an epizootic in central Kentucky that was associated with exposure to eastern tent caterpillars (ETCs). Bacterial isolation from equine pericardial fluid samples was attempted using an insect cell culture growth medium (ICCGM). Using previously cultured, stored frozen samples from four horses with fibrinous pericarditis, inoculation of 10% blood agar plates yielded no growth, whereas simultaneous inoculation of ICCGM resulted in the isolation of Proprionibacterium acnes,...
Dong J, Bao H, Mang L.Rhinoestrus sp. (Diptera: Oestridae) is an economically important parasite that can cause severe nasal myiasis in equids and can also affect humans. The ultrastructure of all Rhinoestrus sp. larval instars from Mongolian horse was examined by light and scanning electron microscopy to characterize the features of Rhinoestrus. The structure of the anterior region, posterior region, and the spines of the third segment was analyzed for 10 specimens in each larval stage. Additionally, 34 third-instar (L3) larvae of Rhinoestrus sp. from Mongolian horse were subjected to molecular characterization by...
Morehead JP, Blanchard TL, Thompson JA, Brinsko SP.To determine features of an early fetal loss (EFL) syndrome and evaluate potential risk factors for EFL in Thoroughbred broodmares on 4 farms in central Kentucky. Methods: Retrospective study. Methods: 288 pregnant broodmares. Methods: Year-2001 breeding records for 288 Thoroughbred broodmares were examined. Early fetal loss was defined as loss of a fetus that was viable at > or = 40 days of gestation but was subsequently lost by 5 months of gestation. Results: Overall 2001 EFL rate was 25% (73/288), median gestational age at time of fetal loss was 77 days, and median date of loss was May 7...
Delvescovo B, Mullen KR, Eicker SW, Ivanek R, Ainsworth DM.Previously we described a clustering of dysphagic foal cases on a Pennsylvania (PA) Standardbred farm which was associated with exposure of pregnant mares to high concentrations of polycyclic aromatic hydrocarbons (PAHs) in the well water. The effect of dysphagia on future athleticism was uncertain. Objective: To determine if, as adults, dysphagic foals were less likely to race and if athleticism (age of first race, Speed Index and Earnings Per Start Index) differed from that of healthy foals that raced as adults. Methods: Prospective cohort study. Methods: All foals born during the study peri...
León B, González G, Nicoli A, Rojas A, Pizio AD, Ramirez-Carvajal L, Jimenez C.Venezuelan Equine Encephalitis virus (VEEV) is an arboviral pathogen in tropical America that causes lethal encephalitis in horses and humans. VEEV is classified into six subtypes (I to VI). Subtype I viruses are divided into epizootic (IAB and IC) and endemic strains (ID and IE) that can produce outbreaks or sporadic diseases, respectively. The objective of this study was to reconstruct the phylogeny and the molecular clock of sequences of VEEV subtype I complex and identify mutations within sequences belonging to epizootic or enzootic subtypes focusing on a sequence isolated from a mare in C...
Bolwell CF, Rogers CW, French NP, Firth EC.There is increasing evidence suggesting that early exercise in Thoroughbred racehorses may be beneficial to the development of the musculoskeletal system. At present, information on the exercise programmes and health problems of individual yearlings during a sales preparation is scant. Objective: To describe the exercise and health problems of Thoroughbred yearlings during preparation for sales, and to identify variations in exercise between and within farms. Methods: A prospective cohort study was used to collect exercise and health information from 18 farms across New Zealand. Daily exercise...
Mizobe F, Takahashi Y, Kusano K.Jockey safety is an important subject from a welfare perspective and public perception. This is the first retrospective case-control study that aims to identify risk factors associated with jockey falls (JF) in Thoroughbred jump races held by the Japan Racing Association (JRA). JF in 17,459 maiden-class race starts at eight racecourses from 2003 to 2017 were retrospectively reviewed. Data were extracted from a database and official accident reports maintained by the JRA. Thirteen possible risk factors were evaluated using multivariable logistic regression to identify those that were significan...
Rodriguez JY, Finneburgh BM, Lewis BC, Flanagan J, Snowden KF.Heterobilharzia americana is a trematode parasite (family: Schistosomatidae) of mammalian wildlife that occasionally infects domestic dogs and horses in the southeastern United States. This report presents the first case of H. americana infection in a Grant's zebra (Equus burchelli boehmi). The parasite was diagnosed post mortem as an incidental finding by histopathologic identification of H. americana eggs in the liver parenchyma after the zebra succumbed in an accidental traumatic death. Molecular analysis of a portion of the parasite small subunit ribosomal RNA gene demonstrated 100% identi...
Sudarshan MK, Ashwath Narayana DH, Ravish HS.Rabies immunoglobulins are life-saving in patients with severe exposure to rabies. Despite the high degree of purification of equine rabies immunoglobulin (ERIG), the product inserts still recommend a skin sensitivity test before administration of this heterologous serum. A recent WHO recommendation states that there are no scientific grounds for performing a skin test before administering ERIG because testing does not predict reactions and it should be given irrespective of the result of the test. In this conflicting situation, we assessed the use of the skin sensitivity test in predicting ad...
Schlichtherle C.This paper describes the importance of fumonisins for human beings and animals and shows data for the occurence in food. Corn-based food samples (n = 299) purchased in the area of munich were analyzed for fumonisin content using an enzyme immunoassay.Fumonisins are mycotoxins produced byFusarium species, especially byFusarium moniliforme andFusarium proliferatum. Occurrence of fumonisins in corn and in cornbased foods and feeds has been reported from almost all over the world. In several animal species different diseases are traced back to fumonisin toxicosis. Fumonisin levels of 5-10 ppm inho...
Lindner A, von Wittke P, Thein P, Strube W.The effect of the prophylactic application of the paramunity inducer Baypamun on the incidence of diseases among foals (n = 63) in four Thoroughbred studs was evaluated. In a blind study, 38 of the foals received 2 ml of Baypamun intramuscularly while 25 of the foals received a placebo at six and four days before weaning and on the fifth day post-weaning. During the observation period of three weeks, beginning with the first and ending ten days after the last application, 7.9% of the foals treated with Baypamun (3 out of 38) suffered from respiratory infections compared to 24% of the foals tre...
Ma Y.Equine rotavirus (ERV) strain L338 (G13P[18]) has a unique G and P genotype. However, the evolutionary relationship of L338 with other ERVs is still unknown. Here whole genome analysis of the L338 ERV strain was independently performed. Its genotype constellations were determined as G13-P[18]-I6-R9-C9-M6-A6-N9-T12-E14-H11, confirming previous genotype assignments. The L338 strain only shared the P[18] and I6 genotypes with other ERVs. The nucleotide sequences of the other 9 RNA segments were different from those of cogent genes of all other group A rotavirus (RVA) strains including ERVs and fo...
Hébert L, Cauchard J, Doligez P, Quitard L, Laugier C, Petry S.There is great concern about the potential pathogen contamination of horse manure compost spread in the same fields horses graze in. To ensure that pathogen destruction occurs, temperatures need to be sufficiently high during composting. Here, we investigated the survival rate of two marker organisms, Rhodococcus equi and Parascaris equorum eggs, exposed to temperatures potentially encountered during horse manure composting. Our results show that the time required to achieve a 1 log10 reduction in R. equi population (D-value) are 17.1 h (+/-1.47) at 45 degrees C, 8.6 h (+/-0.28) at 50 degrees ...
Riley CB, Padalino B, Rogers CW, Thompson KR.There is an increased understanding of shared human-animal risk in terms of "one welfare", whereby when animals are at risk, so are people, so preventing injury to one species may also prevent injury to the other. Because transport-related injuries to horses are common, the authors considered this paradigm to study road equine transport-related injuries to humans in New Zealand. The aim was to determine their frequency and associated factors by distributing a survey to horse industry participants through industry organisations asking about their horse activities, road transport experiences, an...
Dolan M, Cargill C, Martin F, Davenport P, Franks D, Lightfoot J.A bacteriological and serological survey for evidence of contagious equine metritis (CEM) was made during the 1980 breeding season on 3 horse studs in South Australia with a history of previous infection. Swabs from the clitoral sinus and the cervix were cultured for Haemophilus equigenitalis and serum was screened for antibody using the complement fixation test (CFT) and the enzyme-linked immunosorbent assay (ELISA). The specificity of both tests was greater than 0.99 but the ELISA was more sensitive in detecting antibody in infected mares. On the evidence presented it was concluded that H. e...
Steel CM, Devery S, Hance SR, Adkins AR, Hitchens PL.Fragmentation of the dorsal aspect of the distal talus (FDDT), at the dorsolateral articular margin of the proximal intertarsal joint (PITJ) on pre-sale radiographs of yearling Thoroughbreds has not been previously described and data to support decisions made by veterinarians to predict future racing potential of horses with these lesions are lacking. Methods: In this retrospective case-control study we aimed to determine the prevalence of FDDT in juvenile Thoroughbreds and to report their race records. From a database of survey and repository radiographic examinations of 5709 horses, 36 with ...
Tamin A, Rota PA.Hendra virus (HeV) and Nipah virus (NiV) are the causative agents of emerging transboundary animal disease in pigs and horses. They also cause fatal disease in humans. NiV has a case fatality rate of 40 - 100%. In the initial NiV outbreak in Malaysia in 1999, about 1.1 million pigs had to be culled. The economic impact was estimated to be approximately US$450 million. Worldwide, HeV has caused more than 60 deaths in horses with 7 human cases and 4 deaths. Since the initial outbreak, HeV spillovers from Pteropus bats to horses and humans continue. This article presents a brief review on the cur...
Katz J, Geer P.An enzyme-linked immunosorbent assay (ELISA) was developed for the serodiagnosis of contagious equine metritis (CEM), a sexually transmitted disease caused by Taylorella equigenitalis. Antigen preparation was simple, and antigens derived from both classical and atypical forms of T. equigenitalis enabled detection of antibody responses elicted in horses experimentally exposed to either form of the bacterium. Sera serially obtained from these horses from 0 to 63 days postexposure were tested by the traditional complement fixation test (CFT) for CEM and with the ELISA, using both antigens separat...
Eysker M, Boersema JH, Kooyman FN, Berghen P.To determine resistance of small strongyles to albendazole, 3 female ponies (group 1) were grazed on a pasture from May to November 1985 and were treated with 7.5 mg of albendazole/kg of body weight, PO, 2 days before turnout in May and again in June and in July. Three other female ponies (group 2) grazed on a similar pasture from May to July, were treated with 7.5 mg of albendazole/kg, and were removed to another pasture until November. In December, ponies from both groups were treated with 7.5 mg of albendazole/kg, and 8 days later, they were euthanatized and necropsied for a critical test. ...
Harris PA.An outbreak of muscle stiffness and poor performance among 59 thoroughbreds at a Newmarket flat racing yard was investigated between the beginning of May and the end of June 1986. Over a third of the horses showed signs of muscular stiffness, and 38 had, at one or more of the sampling times, creatine kinase (CK) activities above 200 iu/litre and, or, aspartate aminotransferase (AST) activities above 300 iu/litre when they were sampled six to eight hours after exercise. The following season, at a similar time and stage of training, only four of 39 horses sampled had CK activities between 200 an...
Gonçalves LM, Pozzobon R, Dos Anjos BL, Pellegrini DCP, Azevedo MS, Dau SL, Oliveira GP, Klaus R.The term juvenile osteochondral condition (JOCC) has been used to identify developmental changes in the growth plates. The condition is characterized by a set of changes with similar pathogenesis that affect the immature skeleton and joints of growing foals. The aim of the current study is to investigate the prevalence and degree of severity of osteochondral changes in Brazilian warmblood (BW) foals in two farms in the south of Brazil. Radiological evaluation was applied to the metacarpophalangeal (MCP), carpal (C), metatarsophalangeal (MTP), tarsal (T), and femorotibiopatellar (FTP) joints of...
Dusek J, Munk Z.The breeding documentation of the English Thoroughbred horse breeding farm at Napajedla was analyzed to study some effects acting upon the fertility of studs and mares and the length of gravidity. The heritability of fertility is the subject of this report. The normality of the distribution of fertility was tested by processing 300 data on fertility at the given significance level sup / Fn(xi) - F(xi) / less than or equal to Dn(a). The value of the supreme D(300) = 0.108 is lower than the critical level for alpha 0.05. The estimation of fertility heritability coefficient indicates that h2 = 0....
Kalemkerian PB, Metz GE, Peral-Garcia P, Echeverria MG, Giovambattista G, Díaz S.Polymorphisms at Major Histocompatibility Complex (MHC) genes have been associated with resistance/susceptibility to infectious diseases in domestic animals. The aim of this investigation was to evaluate whether polymorphisms of the DRA gene the Equine Lymphocyte Antigen is associated with susceptibility to Equine Arteritis Virus (EAV) infection in horses in Argentina. The equine DRA gene was screened for polymorphisms using Pyrosequencing® Technology which allowed the detection of three ELA-DRA exon 2 alleles. Neither allele frequencies nor genotypic differentiation exhibited any statistical...
Charleston W, McKenna P.Abstract A general review of the epidemiology, significance and control of nematode parasitism of sheep, goats, cattle and deer in New Zealand, the emergence of anthelmintic resistance and its effects, and the search for parasite control strategies that reduce reliance on anthelmintic use, is provided. The research that has formed the basis for present levels of understanding of this complex and important topic is summarised and sources of further information are indicated. Aspects of nematode infections of horses, pigs, dogs and cats, and the history of the liver fluke, Fasciola hepatica, in ...
Sugiura T, Nakajima H.An indirect hemagglutination was developed for the diagnosis of equine infectious anemia using sheep red blood cells coated with group specific virus antigen which had been highly purified by affinity chromatography. The presence of indirect hemagglutination antibodies was demonstrated in horses with equine infectious anemia since the cells were specifically agglutinated by all the serum samples obtained from experimentally infected horses. Antibodies appeared within 35 days after inoculation, and development of which coincided well with that of precipitating and complement fixing antibodies. ...
Wilkołek P, Szczepanik M, Rodzik B, Sitkowski W, Pluta M, Taszkun I, Gołyński M.Intradermal tests (IDTs) and measurement of specific immunoglobulin E class (sIgE) levels in sera are the most common and reliable methods used in allergological clinical practice. The purpose of this study was to explore the sensitization of pollen allergy in atopic horses with pollinosis and to assess the diagnostic value of the multiple allergen simultaneous tests (MASTs) compared with that of the IDT. Twenty-one Malopolski horses with typical skin hypersensitivity symptoms during pollen seasons were enrolled. Intradermal tests were performed, and allergen-specific IgE concentrations in ser...
Bennet ED, Parkin TDH.Racehorse training and racing schedules in many parts of the United States and Canada were interrupted or otherwise reduced during the first three to six months of 2020. This was an indirect consequence of mitigations to prevent the spread of the pandemic virus COVID-19. Data from the Equine Injury Database, a census-level survey of all race starts made in the USA and Canada, were used to analyse the incidence of fatalities in 2009-2022 among three age cohorts of racehorses within each year. There was a statistically significant increase in the incidence of musculoskeletal fatalities among 2-y...
Leary AJ, Kuenzi AJ, Douglass RJ.We examined the effects of grazing on deer mouse () movements into buildings using passive integrated transponder (PIT) technology and small simulated buildings located on 0.6-ha treatment (grazing) and control (no grazing) plots. Twelve experimental 9-day trials were conducted over the course of the study. During these trials, mouse movements into buildings were monitored during three time periods (each 3 days in length). In the treatment plots these time periods corresponded to pre-grazing, grazing, and post grazing by horses. The number of individual deer mice entering buildings over time d...
Kumar S, Rakha NK, Goyal L, Goel P, Kumar R, Kumar A, Kumar S.Theileria equi merozoite surface antigens have been an important candidate for development of diagnostics. We developed ELISA based on EMA-1 recombinant antigen, so as to widen our diagnostic confidence in detection of antibodies against T. equi in sero-surveillance studies. The 547 bp EMA-1 gene fragment encoding high hydrophilic antigenic region was expressed with glutathione-S-transferase tag in prokaryotic system and purified protein (43 kDa) was used for development of ELISA (EMA-1t/ELISA). The EMA-1t/ELISA clearly differentiated T. equi-infected from Babesia caballi-infected horse sera o...
Guimarães AM, Bruhn FRP, Ribeiro MJM, Rosa MHF, de Mello Garcia A, da Rocha CMBM, de Assis Rocha I.Theileria equi, a protozoon in the phylum Apicomplexa, is the causative agent of equine theileriosis. The aim of this cross-sectional study was to determine the prevalence of IgG antibodies against T. equi, by using the indirect fluorescent antibody test (IFAT) reaction and correlating the serostatus with some epidemiological variables relating to the way in which Mangalarga Marchador horses are raised in southern Minas Gerais, Brazil. In this study, 506 horses were used, all clinically healthy, on 53 horse farms distributed across 27 municipalities in southern Minas Gerais. The statistical te...
