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.
Siles-Lucas M, Cuesta-Bandera C.A comparison was made, by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), of excretory/secretory (ES)-crude and immunopurified (with the corresponding anti-host serum) hydatid fluids-and somatic (S)-protoscoleces-proteins, from several ovine, equine, swine, bovine and human Echinococcus granulosus Spanish isolates. Likewise, the host influence on parasitic ES protein expression was studied, comparing purified hydatid fluids from ovine and equine cysts obtained from natural hosts and in RNMI mice. Purified hydatid fluids patterns, under reducing conditions, yielded the mos...
Weaver SC, Salas R, Rico-Hesse R, Ludwig GV, Oberste MS, Boshell J, Tesh RB.Venezuelan equine encephalomyelitis (VEE) virus has caused periodic epidemics among human beings and equines in Latin America from the 1920s to the early 1970s. The first major outbreak since 1973 occurred in Venezuela and Colombia during 1995, and involved an estimated 75,000 to 100,000 people. We report an epidemiological and virological investigation of this epidemic. Methods: Virus isolates were made in cell culture from human serum, human throat swabs, and brain tissue from aborted and stillborn human fetuses, as well as from horse brain tissue and pooled mosquito collections. Human sera ...
Carr EA, Spier SJ, Kortz GD, Hoffman EP.Evaluate histories, clinical signs, and laboratory data of 69 horses homozygous by DNA testing for hyperkalemic periodic paralysis (HPP). Methods: Cohort study. Methods: 69 of 189 horses testing homozygous for HPP between October 1992 and November 1994. Methods: Questionnaires addressing signalment, training regimes, medical history, and current status of affected horses were sent to owners, trainers, or attending veterinarians. Data from completed questionnaires were tabulated and evaluated, using descriptive statistics. Results: Sixty-nine (37%) of 189 questionnaires were completed and retur...
Aleman M, Spier SJ, Wilson WD, Doherr M.To describe clinical manifestations of Corynebacterium pseudotuberculosis infection in horses and to evaluate diagnostic methods for identification of this disease. Methods: Retrospective case series. Methods: 538 horses with a diagnosis of C pseudotuberculosis infection. Results: Median age of horses with external abscesses was similar to that in horses with internal abscesses. Breed and sex did not appear to be associated with infection. Cases were detected during all 12 months; however, the disease was most common in the fall and early winter, with the highest incidence in September, Octobe...
Hartmann FA, Callan RJ, McGuirk SM, West SE.Salmonella anatum was isolated from horses treated at a private veterinary clinic or at a university veterinary medical teaching hospital. All isolates were resistant to most commonly used antibiotics. Because of the severity of disease resulting from outbreaks of infections with drug-resistant strains of S anatum, an epidemiologic investigation was conducted. Enteric bacteria, including S anatum, that were resistant to most antibiotics were isolated from the private veterinary clinic environment. Salmonella anatum was not isolated from the university teaching hospital environment. To prevent ...
Kane AJ, Stover SM, Gardner IA, Case JT, Johnson BJ, Read DH, Ardans AA.To evaluate selected shoe characteristics as risk factors for fatal musculoskeletal injury (FMI) and specifically for suspensory apparatus failure (SAF) and cannon bone condylar fracture (CDY) of Thoroughbred racehorses in California. Methods: Case-control study. Methods: Thoroughbred racehorses (n = 201) that died of were euthanatized at California racetracks between August 1992 and July 1994. Methods: Shoe characteristics were compared between case horses affected by FMI (155), SAF (79), and CDY (41) and control horses that died for reasons unrelated to the appendicular musculoskeletal syste...
Kane AJ, Stover SM, Gardner IA, Case JT, Johnson BJ, O'Brien MJ, Read DH, Ardans AA.To develop a standard technique for evaluation of racehorse shoes, to assess homotypic variation (interlimb variation) in shoe characteristics, and to determine whether shoe characteristics varied with age and sex. Methods: Cross-sectional study. Methods: Thoroughbred racehorses (n = 201) that died or were euthanatized at California racetracks between August 1992 and July 1994. Methods: Shoe characteristics were measured on horses examined after death. Percentage of agreement was used to compare shoe characteristics between limbs (homotypic variation). Using chi 2 analysis, shoe characteristic...
Bada R, Mittal KR, Higgins R.A total of 50 Actinobacillus suis isolates were studied for their biochemical and antigenic characteristics. Of them, 40 isolates originated from different tissues of diseased pigs, and the other ten isolates were from horses with respiratory problems. There was no major biochemical difference among equine and porcine A. suis isolates. Results of tube agglutination tests showed that porcines isolates were antigenically homogeneous while equine isolates were heterogeneous.
Paré J, Carpenter TE, Thurmond MC.To determine whether clustering existed in the spatial or temporal distribution of horses that shed Salmonella krefeld in their feces during hospitalization. Methods: Retrospective analysis of medical records. Methods: 219 horses housed in the intensive care unit of a veterinary medical teaching hospital from October 1991 through May 1992. Methods: Bacteriologic culturing of fecal samples was used to identify horses shedding S krefeld. For affected horses, the scan statistic was used to analyze temporal clustering, and Knox's method was used to analyze temporal-spatial clustering. Results: 20 ...
Daugschies A.Drug resistance of parasites is a worldwide problem of increasing importance in animal production. Considerable information is available on the development of resistance in chicken coccidia and in strongyles of horses, sheep, goats and pigs. A review is given of the development, incidence, and management of drug resistance with emphasis on the situation in Germany.
Hyatt AD, Selleck PW.The ultrastructure of the equine morbillivirus (EMV) which was implicated in the death of one human and fourteen horses in Queensland, Australia during September 1994 and a 36 year old man from Queensland in October 1995 is described. The ultrastructure of the virus and the intracellular virus-specific structures are characteristic for the family Paramyxoviridae. Cytoplasmic nucleocapsids were observed within the infected cells monolayers, endothelial cells (lung) of infected horses and the neurons within the brain of the 36 year old Queensland man. Aggregates of smaller nucleocapsid-like stru...
Wilson DA, MacFadden KE, Green EM, Crabill M, Frankeny RL, Thorne JG.Trimethoprim-potentiated sulphonamides (TPS) are among the most frequently administered antimicrobials in equine medicine. Anecdotally, TPS has been implicated as a cause of mild to moderate diarrhea in horses. The purpose of this study was to document the prevalence of diarrhea in horses receiving TPS, to characterize the severity of the diarrhea, and to identify any other factors associated with the development of diarrhea. A 2-part study was designed to identify the prevalence of diarrhea associated with TPS in our clinic population. Part I was a case-control retrospective study of 135 reco...
Vullo V, Mastroianni CM, Lichtner M, Mengoni F, Chiappini E, D'Agostino C, Delia S.Thirty healthy blood donors, 15 workers from horse-breeding farms, 69 human immunodeficiency virus (HIV)-negative persons at risk for HIV infection, 125 HIV-infected subjects without Rhodococcus equi infection, and nine HIV-infected patients with Rhodococcus equi pneumonia were evaluated in order to detect serum antibodies to Rhodococcus equi precipitate-soluble antigen by an enzyme immunoassay (EIA). Whereas EIA values for healthy donors, horse farm workers, individuals at risk for HIV infection, and HIV-positive subjects without Rhodococcus equi infection were comparable, HIV-infected patien...
Ross WA, Kaneene JB.To evaluate outbreaks of disease attributable to eastern equine encephalitis virus (EEEV) in horses in Michigan, and the associated environmental patterns and weather conditions, so that factors could be identified that may have predisposed horses in specific areas of the state to infections with EEEV. Methods: Epidemiologic retrospective records analysis. Methods: Data on EEEV vectors, wild-bird reservoir hosts, and incidental hosts, including horses and human beings, obtained from census reports and medical records compiled between 1942 and 1991. Methods: Patterns detected during outbreaks o...
Green BE, Foil LD, Hagius SD, Issel CJ.Equine infectious anemia virus (EIAV) was injected intrathoracically into Aedes aegypti, Stomoxys calcitrans, and Tabanus fuscicostatus, and fed to Ae. aegypti in suspensions of either artificial blood of Eagle's Minimum Essential Medium. Insects were stored at -70 degrees C for up to 9 months before testing for the presence of EIAV. The viral tissue culture titers detected from stored insects were similar to those from insects tested at time 0.
Dolvik NI, Gaustad G.The degree of lameness of 265 randomly selected three-year-old standardbred trotters was assessed on a fixed point scale with 0 indicating soundness and 5 indicating that the animals were not weightbearing. Two variables were used to describe the signs of lameness; one was the continuous variable: the sum of the initial lameness score and the lameness scores after separate flexion tests of the carpal, stifle/tarsal and phalangeal joints and the second was the bivariate variable; the ratio of lame/sound horses. The mean (sd) heritability of the continuous variable was estimated to be 0.25 (0.21...
Martínez-Torrecuadrada JL, Díaz-Laviada M, Roy P, Sánchez C, Vela C, Sánchez-Vizcaíno JM, Casal JI.African horsesickness virus serotype 4 (AHSV-4) outer capsid protein VP2, or VP2 and VP5 plus inner capsid protein VP7, derived from single or dual recombinant baculovirus expression vectors were used in different combinations to immunize horses. When the proteins were purified by affinity chromatography, the combination of all three proteins induced low levels of neutralizing antibodies and conferred protection against virulent virus challenge. However, purified VP2 or VP2 and VP5 in the absence of VP7 failed to induce neutralizing antibodies and protection. Immunization with non-purified pro...
Hasslinger MA, el-Seify MA.The investigation of 156 donkeys in the area of the veterinary faculty of the Tanta University in Kafr el-Sheikh showed that 49 animals (31.41%) were infected with trematodes, 34 donkeys (21.80%) served as hosts for Gastrodiscus aegyptiacus, 22 (14.10%) were infected with Fasciola gigantica und 7 (4.49%) with both trematodes. 6 of 40 examined horses (15.0%) showed monoinfections with G. aegyptiacus only. Because of the fragmentary knowledge on these paramphistomides of equids, some aspects concerning the morphology, pathology and clinical symptoms, differential diagnosis, occurrence, host spec...
Allen AL, Townsend HG, Doige CE, Fretz PB.A case-control study was conducted to identify risk factors for the congenital hypothyroidism and dysmaturity syndrome of foals. A questionnaire was used during personal interviews of foal owners and farm managers to collect information on animal signalment, farm environment, and mare management. Information on 39 foals with the congenital hypothyroidism and dysmaturity syndrome were compared with 39 control foals. Foals with the syndrome had a significantly (P < 0.0001) longer gestation (357.6 d) than control foals (338.9 d). Pregnant mares that were fed greenfeed, did not receive any supplem...
Cohen ND, Martin LJ, Simpson RB, Wallis DE, Neibergs HL.To compare the sensitivity of polymerase chain reaction (PCR) with microbiological culture for detecting salmonellae in equine fecal samples and equine environmental swab specimens. Methods: Samples and specimens were tested by PCR and microbiological culture. Methods: A fecal sample from each of 152 horses admitted consecutively to the clinic for evaluation by the outpatient service, 282 fecal samples from 110 hospitalized horses that had been submitted to the clinical microbiology laboratory, and 313 environmental swab specimens were examined. Methods: Each sample and specimen in the study w...
Barlough JE, Madigan JE, DeRock E, Bigornia L.A nested polymerase chain reaction for detecting Ehrlichia equi in horses and ticks (Ixodes pacificus) was developed. A major second-round PCR product of 928 bp could be readily visualized in ethidium bromide-stained agarose minigels. An internal probe was used to verify the identity of the amplified product by non-radioactive (digoxigenin-based) Southern blotting; additional confirmation was provided by DNA sequence analysis. A dilution study testing the sensitivity of the PCR indicated that DNA derived from 3 infected neutrophils was sufficient to generate a PCR signal. The specificity of t...
Timoney PJ.A highly contagious virus infection of horses, influenza is the single most important equine respiratory disease in many countries. Two subtypes of equine influenza virus have been identified, A/equine-1 and A/equine-2, neither of which immunologically cross-reacts. In the case of A/equine-2 virus, two lineages exist, American and European, which appear to have evolved independently of one another. The acute febrile respiratory disease characteristic of influenza is frequently complicated by secondary bacterial infection, especially in unvaccinated horses. Primarily a respiratory-borne infecti...
Langemeier JL, Cook SJ, Cook RF, Rushlow KE, Montelaro RC, Issel CJ.Control of equine infectious anemia (EIA) is currently based on detection of anti-EIA virus (EIAV) antibodies. However, serologic diagnostic methods may give false-negative results in infected horses that fail to respond adequately or are in the early stages of infection. We developed a reverse transcriptase nested PCR (RT-nPCR) assay for the detection of viral gag gene sequences in plasma from EIAV-infected horses. The ability of RT-nPCR to detect field strains of EIAV was investigated by assaying plasma samples from 71 horses stabled on EIA quarantine ranches. Positive PCR signals were detec...
Zendri F, Isgren CM, Sinovich M, Richards-Rios P, Hopkins KL, Russell K, Groves N, Litt D, Fry NK, Timofte D. () may cause diphtheria in humans and can be carried by a wide range of animal species including dairy cows and, more recently, dogs and cats that have been increasingly involved in zoonotic trasmission. We isolated and characterized, by WGS, a toxigenic strain from a diseased horse in the United Kingdom showing clinical signs of respiratory diphtheria comparable to those seen in people. Our results indicate a role for horses as reservoirs for zoonotic .
Bowie J, Mason PC, Oudemans G, Montgomery RH.Cysts found in the liver of a horse which had never been out of New Zealand were used to infect two dogs which were slaughtered 35 days after infection. Large numbers of Echinococcus granulosus were recovered. These cestodes were compared with mature dog-sheep cestodes, using light and scanning electron microscopy and identified as the dog-horse strain of E.granulosus.
Hagiwara K, Momiyama N, Taniyama H, Nakaya T, Tsunoda N, Ishihara C, Ikuta K.Sero- and molecular-epidemiological studies on Borna disease virus (BDV) infection show that BDV RNA is not always detected in the peripheral blood mononuclear cells (PBMCs) from serum anti-BDV antibody-positive individuals such as horses, sheep, cattle, cats, and humans. In this study we demonstrated BDV RNA signals by polymerase chain reaction only in restricted regions of the brain from horses with locomotor disease. Four of six horses examined showed apparently positive reactions for anti-BDV antibodies. Specific regions of the brain of these four horses were positive for BDV RNA but the i...
Chabchoub A, Landolsi F, Zientara S, Amira A, Mejri M, Ghorbel A, Ghram A.The authors describe an equine influenza epizootic that occurred in Tunisia during February and March 1998 in the regions of Tozeur, Sousse and Tunis. They relate the symptoms, the different stages of diagnosis and the serological results.