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.
Sabine M, Feilen C, Herbert L, Jones RF, Lomas SW, Love DN, Wild J.Until 1977 no case of abortion caused by equine herpesvirus 1 (EHV1) had been recorded in Australia although the virus, called equine rhinopneumonitis virus, had been known to have been present at least since 1962. Outbreaks of EHV1 abortion occurred in New South Wales in 1977 and in 1981. Sporadic cases of EHV1 abortion had been confirmed in some parts of Australia each year since 1975. It was concluded that an abortigenic subtype of EHV1 had been introduced to Australia in 1977 and that the previously endemic respiratory subtype occasionally caused abortion. Virus isolation in a variety of c...
De Vroey C, Wuytack-Raes C, Fossoul F.Several M. praecox isolates of saprophytic origin were obtained in Belgium from horses and their surroundings. Visualization of macroconidia in dust collected in stables proved its saprophytic origin. A few strains were obtained from human cases of tinea corporis.
Warner A, Mayhew IG.Anhidrosis is loss of the ability to sweat. The problem is seen in horses kept in a hot humid climate, and it may cause severe impairment of thermoregulation in the equine athlete. British Thoroughbreds imported to her tropical colonies are the earliest recorded cases, and since then the syndrome has come to be described as one of Thoroughbreds, usually performance athletes, undergoing acclimatization to heat and humidity. A recent epidemiologic study of cases in Florida has shown, however, that many different breeds, and long time inhabitants of a hot climate, may be affected. Equine sweat gl...
Hoshino Y, Wyatt RG, Greenberg HB, Kalica AR, Flores J, Kapikian AZ.A rotavirus, designated as the H-1 strain, was isolated from a diarrheic foal in primary African green monkey kidney cells and MA104 cells. This cell culture-adapted strain hemagglutinated erythrocytes of human group O, rhesus monkeys, guinea pigs, and sheep. It was found to be similar, if not identical, to porcine rotaviruses (strains OSU, EE, and A-580) by plaque reduction neutralization and hemagglutination inhibition tests, and, in addition, it was found to belong to subgroup 1. This equine rotavirus has an RNA electrophoretic migration pattern which was distinct from those of the three st...
Tunnell JA, Sanders JO, Williams JD, Potter GD.Pedigrees of randomly selected Quarter Horses born in each of the years 1946, 1956, 1966 and 1976 and of winning halter, cutting and race horses born in the same years were evaluated and compared. Average inbreeding and inter se relationship levels and relationships of influential ancestors to the sample were calculated for each sample. The amount of Thoroughbred influence and the average generation interval were also determined for each random sample. The levels of inbreeding found in the random samples were low, ranging from 1.3% in 1956 to 2.6% in 1966; however, these levels were higher tha...
Morris DD, Whitlock RH, Palmer JE.Fecal samples from 74 horses with diarrhea were examined microscopically for leukocytes and epithelial cells. The diarrhea was categorized as either acute (less than two weeks) or chronic, Salmonella positive or negative, and mild or severe (based on the fecal consistency). A large number of fecal leukocytes was strongly suggestive of salmonellosis; however, approximately 1/3 of the horses with Salmonella-negative diarrhea also shed fecal leukocytes. Fecal leukocytes were more common in horses with acute and/or severe diarrhea regardless of cause. Numbers of fecal colonic mucosal epithelial ce...
Conner ME, Gillespie JH, Schiff EI, Frey MS.A total of 142 equine fecal samples (93 field fecal and 49 experimental fecal specimens) were examined for rotavirus using direct electron microscopy (EM) and the Rotazyme test. Eighty-six stool specimens were diarrhea samples. The Rotazyme test sensitivity and accuracy as compared to EM was determined by the visual (color reaction) and spectrophotometric methods. The overall agreement was 94.8% and 92.3% between EM and Rotazyme visual and spectrophotometric methods, respectively when suspect reactions (1 + color reaction or net absorbance between 0.05 and 0.1) were not included. The Rotazyme ...
Hathaway SC, Little TW, Stevens AE, Ellis WA, Morgan J.Eighteen isolates from the Australis serogroup from free-living and domestic animals were identified using the cross agglutination absorption test. Serovar muenchen was found only in England and Wales in wood mice, short tailed and bank voles, a grey squirrel and a pig. Serovar bratislava was found in hedgehogs in England, Wales and Northern Ireland and also in a brown rat from Northern Ireland. Serovar bratislava was isolated from sheep in both England and Northern Ireland and from horses in Northern Ireland. The distribution of these serovars in relation to possible maintenance hosts is disc...
Silver IA, Brown PN, Goodship AE, Lanyon LE, McCullagh KG, Perry GC, Williams IF.This project was carried out over a five year period (1977 to 1981 inclusive) at the University of Bristol following discussion between the British Veterinary Association and the Royal College of Veterinary Surgeons about the efficacy of, and ethical justification for, the practice of 'firing' (cautery). These discussions had been promoted by parliamentary questions but led to no firm conclusions because previously reported clinical investigations on specific treatments lacked adequate comparisons and controls and thus did not provide scientifically acceptable, statistically valid data. The pr...
Coffman JR, Colles CM.Sensitivity to insulin was assessed in ponies episodically affected with chronic laminitis by measurement of blood glucose and arterial blood pressure during insulin tolerance tests. In terms of blood glucose values, laminitic ponies were significantly less sensitive to insulin than controls. Conversely, a post-insulin decline in diastolic, systolic and mean blood pressure values was significantly greater in laminitic ponies than in controls.
Ottley ML, Dallemagne C, Moorhouse DE.Investigations were conducted on the taxonomy, distribution in the carcase, pathology and transmission of Onchocerca spp. in equids from Queensland and the Northern Territory. Examination of small groups of horses and ponies revealed high infection rates with O. cervicalis, while lesser numbers were infected with O. gutturosa. O. reticulata was not found. Neither of the Australian species is likely to be of economic importance to the horsemeat industry. The findings support the belief that O. cervicalis is a pre-disposing factor in the aetiology of equine nuchal disease, most commonly seen cli...
Stubley D, Campbell C, Dant C, Blackmore DJ, Pierce A.The concentration of copper and zinc in the blood and sera of over 300 Thoroughbreds in training was determined by atomic absorption between February 1979 and July 1981. The mean (+/- sd) concentration of copper in the serum of stabled Thoroughbreds (79 +/- 16 micrograms/dl) was significantly (P less than 0.0001) lower than that of those at grass (101 +/- 26 micrograms/dl), whereas the mean serum zinc concentration of stabled Thoroughbreds (170 +/- 54 micrograms/dl) was higher than that of those at grass (111 +/- 45 micrograms/dl). No such differences were observed in whole blood. There were m...
George JL, Reif JS, Shideler RK, Small CJ, Ellis RP, Snyder SP, McChesney AE.During an outbreak of strangles in a population of research horses, 4 mares were identified as carriers of Streptococcus equi. Three of the mares had typical signs of strangles (severe regional lymphadenitis with or without rupture of abscessed lymph nodes). The 4th mare experienced episodes of serous to mucopurulent nasal discharge, but never had more than a mild degree of lymph node enlargement. Streptococcus equi was isolated from the abscessed lymph nodes and from nasopharyngeal swab specimens from the first 3 mares from 6 to 19 weeks after rupture of involved nodes. Streptococcus equi was...
Mirck MH, Eysker M, Jansen J.Proceeding on the epidemiology of Strongylidae infection in horses, the effects of combined anthelmintic treatment and moving to non-contaminated pasture in July were studied during 1981 and 1982. This strategy for control was found to be effective as was shown by faecal examination, pasture larval counts and post-mortem worm counts. No significant contamination or worm infection developed in the group of treated ponies moved to celan pasture after July 1. On the permanently grazed pasture the same pattern of infection developed as on the pasture where up to July 1 ponies and subsequently shee...
The Journal of hygieneJune 1, 1983
Volume 90, Issue 3 371-384 doi: 10.1017/s0022172400029004
Wood JM, Mumford J, Folkers C, Scott AM, Schild GC.Serological responses to three bivalent aqueous equine influenza vaccines of different potency and an adjuvanted bivalent vaccine containing inactivated A/equine/Prague/56 (H7N7) and A/equine/Miami/63 (H3N8) viruses, were examined in seronegative ponies. Potencies of the vaccines, measured by single-radial-diffusion tests, ranged from 4 to 56 micrograms of haemagglutinin (HA) antigen activity/virus strain per dose. Serological responses to vaccination were examined by haemagglutination-inhibition (HI) and single-radial-haemolysis (SRH) tests. Four weeks after a primary dose, HI responses to bo...
Gabal MA, Hassan FK, Siad AA, Karim KA.A detailed clinical and mycological study of horse infections with Histoplasma farciminosum was conducted for the first time in the Middle East. The disease seems to prevail in endemic form in the region. In all of the cases studied the infection involved only the cutaneous lymphatics and skin tissue with extension to the regional draining lymph glands. The disease seems to impose serious economic impact in the infected areas. Full description and thorough characterization of both the mycelial form and the yeast phase of the causative fungus were made.
Cybinski DH, Zakrzewski H.CSIRO 368 virus was isolated from blood collected in the Northern Territory from a healthy cow and electron microscope studies showed that the isolate had rhabdovirus morphology. Fluorescent antibody studies and complement fixation tests related the virus to bovine ephemeral fever (BEF) virus. Neutralization tests in both suckling mice and Vero cells showed that the virus was not BEF virus. Antibodies to CSIRO 368 virus were found in cattle sera from northern and eastern Australia and Papua New Guinea. Antibodies were found in 16 out of 45 buffalo, some of which also had antibodies to BEF viru...
Bastianello SS.A survey was carried out on the neoplasms of horses, donkeys and mules which are recorded in the registration files of the Section of Pathology of the Veterinary Research Institute, Onderstepoort, in the Republic of South Africa, over a 40-year period from 1935 to 1974. A total of 378 tumours are recorded, 339 of which were in horses, 32 in mules and 7 in donkeys. Sarcoids (38%), squamous cell carcinomas (23,5%), fibromas (8,2%), melanomas (8,0%), papillomas (4,5%), fibrosarcomas (3,4%) and lymphosarcomas (3,0%) accounted for 88,6% of the total. Of the 58 sarcoids for which the site or origin ...
Braverman Y, Ungar-Waron H, Frith K, Adler H, Danieli Y, Baker KP, Quinn PJ.A survey of sweet itch in horses in Israel based on a questionnaire to owners reported that 158 of 723 horses (21.8 per cent) had sweet itch lesions. The results indicated that the likelihood of a horse acquiring sweet itch decreased with increasing altitude but no definite association with rainfall zones was evident. Variation in the density of the horse population, however, obscured these observations. In the population surveyed, stallions were more sensitive than mares and pale horses appeared to be less sensitive than dark ones, but the sample size of this latter group was much smaller. In...
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...
Uehara N, Momose A.The doping test method used in a horse race requires the accurate detection of a wide variety of drugs and metabolites as well as the rapidity in order to examine a large number of samples within a limited time. For this purpose, the routine method consists of a preliminary screening and a confirmatory test. In this paper, a historical review for the development of the doping test method in Japan is described. The metabolism and pharmacology of drugs in horses are also discussed.
HETRICK FM, YANCEY FS, HANSEN PA, BYRNE RJ. Four horses inoculated with EEE virus remained asymptomatic following injection but did develop measurable HI and neutralizing antibodies as a result of infection. HI antibodies were detectable earlier than neutralizing antibodies but the levels tended to drop more rapidly. 2. Of 14 horses and ponies having significant levels of neutralizing antibody, 5 to 9 had measurable HI antibody depending on number of units of antigen employed in the test. 3. Sera from 3 clinical cases of EEE were positive on the HI test while only one of these animals had a significant neutralizing antibody level.
Bell LG, Lowe JE.A questionnaire was designed to determine the incidence of major injuries, severe colic, and acute laminitis in horses at American Horse Shows Association (AHSA) A- and B-rated shows, ie, those shows requiring a veterinarian in attendance. The questionnaire was sent to the show stewards and filled out by the attending veterinarians of the AHSA A- and B-rated shows held from January 1982 to October 1984. Of 2,952 questionnaires sent out, 799 (27%) were completed and returned by veterinarians; 99 of them were discarded because of incomplete or misleading information. The study revealed a low inc...
Juul SM.During the period from 1.1. to 31.12.1988, 104 patients with injuries resulting from riding or other forms of direct contact with horses were examined and treated in a casualty department in the County of Vejle. Antecedent data from these patients were collected. The majority of injuries occurred on falling from the horse and involved particularly the upper part of the body. The commonest injuries were bruises which did not require special treatment. The relationships between concussion, fracture of the humerus and fracture of the clavicle and riding were investigated by odds ratio. Much fewer...
of surveillance testing, April to June 2017International disease occurrence in the second quarter of 2017These are among matters discussed in the most recent quarterly equine disease surveillance report, prepared by Defra, the Animal Health Trust and the British Equine Veterinary Association.
Brown SM, Miller DV, Vezina D, Dean NC, Grissom CK.This case report describes a woman presenting after out-of-hospital cardiac arrest with several cardiac anomalies, including a form fruste of Ebstein's anomaly complicated by a large tricuspid valve vegetation. On autopsy, she proved to have unstable plaques in epicardial vessels that likely caused arrhythmic sudden cardiac death, a reminder that even in the presence of rare anomalies, common things are common.
Brown VA, Wilkins PA.Techniques for novel approaches to the diagnosis and management of equine pulmonary disease continue to be developed and used in clinical practice. Diagnostic techniques involving immunoassays and nucleic acid-based tests not only decrease the time in which results become available but increase the sensitivity and specificity of test results. These assays do not substitute for careful clinical evaluation but can shorten the time to a confirmed accurate diagnosis, and thus allow for early initiation of therapeutic strategies and prevention protocols. With further understanding of the molecular ...
Kihm U, Ackermann M.The objective of the present review was to summarize current knowledge of African horse sickness (AHS), based on available literature (which is nonetheless relatively scant) and recent information obtained from the O.I.E. Brief description is made of the biology of AHS virus (an arbovirus, transmitted by Culicoides imicola), isolation of the agent, diagnosis by serotyping procedures, and preventive measures (such as protection of horses from insect infestation, or vaccination programs) which may be taken. The recent outbreaks in Spain, Portugal, and Morocco, have demonstrated that much more re...
Gimsing S.Occupational injuries are notifiable in Denmark. Hitherto, occupational injuries caused by riding and horse handling have not been reported. Methods: This retrospective study comprises all cases reported to the National Working Environment Authority during the period 1992-1999. Results: There were 634 occupational accidents, and 43% of the victims were below the age of 25 years with a four-in-one female preponderance. In contrast, there were only three cases of occupational disease. Conclusions: Occupational diseases ought to be much more common than suggested by these few reported cases. Resp...