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.
Simms JG, Rosser WW.A case of Farmer's Lung in a city dweller who rides horses for recreation is reported. A survey of the members of an urban riding club found that 13% of the persons surveyed had antibodies to T. polyspora in their circulation.Comparing the average rainfall in the area of the riding club to average rainfall throughout regions across the country, it is likely that Farmer's Lung is more prevalent than previously thought.More information about the incidence of this preventable respiratory disease in Canada is needed.
Oki Y, Miura K.In the recent years, various red cell auto-antibodies have been determined in someanimal diseases, including autoimmune hemolytic anemia and systemic lupus erythe-matosus in dogs, ") Aleutian disease in minks, 8) and equine infectious anemia."?">In this report, the red cell auto-antibodies were examined for symptomatiCchanges, serological characteristics, and immunopathological roles in 20 horses infectedwith equine infectious anemia virus (Table l).Pathologic cold hemagglutiuain and warm hemagglutinin were identified in theplasma of artificially infected horses. The direct antiglobulin tests ...
In February 2021, a serious EHV-1 outbreak occurred at an international jumping competition in Valencia, with several subsequent outbreaks in various European countries. As a consequence, several equestrian associations introduced compulsory vaccination against EHV-1, and in the immediate aftermath of the outbreak, demand for EHV vaccinations increased sharply. The initial concern has now dissipated. One equestrian association has abolished the compulsory vaccination that had only been introduced a year before, and a general debate began questioning the efficacy and safety of EHV-vaccines. Thi...
Whitlock F, Grewar J, Newton R.The epidemiology of equine influenza (EI) in the United Kingdom has not been systematically described since the 2019 epidemic. Objective: To summarise UK EI surveillance (2020-2024), quantify outbreak seasonality and assess movement-related sources. Methods: Retrospective observational analysis of national surveillance and horse importation data. Methods: Epidemiological data for laboratory-confirmed EI cases in the United Kingdom were collated. Outbreaks (EI-infected premises) were defined as one or more laboratory-confirmed cases on the same premises within a 4-week period. Monthly outbreak ...
Luthersson N, Harris PA, Parkin T, Þorgrímsdóttir ÚÝ, Bennet ED.It is unknown whether the high prevalence of Equine Squamous (ESGD) and Equine Glandular (EGGD) Gastric Disease in extensively grazed Icelandic horses in the autumn/winter is seasonally driven. Objective: To determine the prevalence of, and risk factors for, gastroscopically significant ESGD (ESGD:score of ≥2/4); gastroscopically severe ESGD (ESGD:score of ≥3/4) and gastroscopically significant EGGD (EGGD:score of ≥1/2) in extensively pasture-managed Icelandic horses at four timepoints. Methods: Prospective longitudinal cohort. Methods: Gastroscopy was undertaken in 80 Icelandic horses (...
Malek IA, Baharudin F, Peng TL, Sabri J.Equine strongyles are harmful gastrointestinal parasites affecting horses' health and productivity. In tropical regions, environmental conditions, including temperature and soil type, significantly influence the development and survivability of strongyle larvae. This study aims to assess the development and survival of third-stage larvae (L3) of strongyles under different temperatures and soil types commonly found in Malaysia. Faecal samples from five adult horses aged between 22-24 years that were kept under a semi-intensive management system and had no history of recent anthelmintic treatmen...
Germann JA, O'Sullivan TL, Greer AL, Spence KL.This study aimed to describe implementation of biosecurity practices by Ontario horse owners and investigate whether biosecurity implementation was associated with horse-owner demographic characteristics and personality traits. Unassigned: A cross-sectional questionnaire was administered to a convenience sample of horse owners in Ontario to collect data on demographics, personality traits, risk comprehension, and biosecurity practices. Hierarchical cluster analysis was used to identify clusters of participants with shared personality traits, and univariable associations between clusters and de...
Eysker M, Wemmenhove R.The epidemiology and control of helminth infections in the horse were studied in four small grazing experiments between 1981 and 1984 at the University of Utrecht. At autopsy in November or December negligible Strongylus vulgaris burdens were found in the cranial mesenteric artery of four groups of ponies, which had been treated with an anthelmintic in July and subsequently transferred to a clean pasture. Considerable arterial S. vulgaris burdens were seen in three groups of ponies which were treated with an anthelmintic in July without a move to clean pasture, and in another group of ponies i...
Schmidt GM, Coley SC, Leid RW.A histopathological study of ventral midline skin from midwestern U.S. horses with and without onchocerciasis due to Onchocerca cervicalis found perivascular mononuclear dermatitis as the most consistent difference between the two groups. Seasonal variation in parasite numbers or cellular influxes was not observed. Eosinophilic dermatitis was observed in horses with onchocerciasis and dermatitides of unknown etiology.
Powell DG, Whitwell K.Following an outbreak of CEM in England during 1977 a Code of Practice was introduced to control the disease in 1978. The Code recommended a bacteriological screening programme for Thoroughbred mares and stallions and improved standards of hygiene on the stud farm. As a result of the implementation of the Code a number of asymptomatic carrier mares was detected. Stallions which had transmitted CEM in 2977 and were treated did not transmit the disease during 1978. Two small outbreaks of CEM were reported during the 1978 breeding season.
Hillidge CJ, Whitlock TW.Post race endoscopy was carried out on 255 two-year-old quarter horses and exercise-induced pulmonary haemorrhage (EIPH) was diagnosed in 166 (65 per cent) of them. Visible epistaxis was seen in a higher proportion of geldings than in either mares or stallions. The prevalence of EIPH was similar in mares (73 per cent) and in geldings (74 per cent). A significantly lower prevalence (49 per cent) was noted in stallions (P less than 0.01). It was concluded that a sex variation in the prevalence of EIPH exists in two-year-old quarter horses.
Frey R, Lieb A.An outbreak of abortion due to the equine herpesvirus-1 (EHV-1) in the eastern part of Switzerland is reviewed. Seven of eleven pregnant mares aborted within twenty-three days in January 1989. Four weeks later another foal died a few minutes after parturition. Three mares delivered live foals in February, March and April without any complications. The examination of the eight dead foals revealed an EHV-1 Infection. The clinical signs and the pathology are discussed. Severe complications during the early post-parturient time are in contrast to the uncomplicated outcome mentioned by other author...
Brennvall HM, Bjune T, Sverdrup Ø, Ráki M, Abedini S.Zoonoses are important to consider when humans become ill after being in contact with animals. In such cases thorough patient history is crucial, especially when infections have an unclear cause. We present a patient with infection-associated glomerulonephritis, where a horse was the probable source of infection. A young woman was admitted to the district general hospital in Vestfold, Norway, with infection and acute kidney failure. Renal biopsy suggested glomerulonephritis, and nasopharyngeal culture taken at admission detected Streptococcus equi. It emerged that the patient had daily contact...
Bischoff K, Moiseff J.Feed as a cause of poisoning in horses can occur on small or large scales. It is challenging to work up cases of suspected feed contamination, but there are resources available to veterinarians and owners. Feed contamination can be chemical or biological. This article focuses on and provides examples of chemical feed contamination including misformulation, adulteration, and natural contaminants. Additionally, recommendations for feed sampling and diagnostic submission, including legal documentation, are included.
Rastegaev IuM.10 foals were artificially infected for the first time with eggs of Gastrophilus intestinalis, G. veterinus, G. haemorrhoidalis, G. inermis, G. nigricornis. 63 to 67% of the 1st stage larvae die in the first period of life after emergence from the egg, at the moment of invasion into the skin and at the beginning of the migration. In 40 to 45 years after the infection most larvae (73 to 82%), depending on their specific belonging, were found in the stomach, duodenum and rectum.
Sugiyama F, Takahashi Y, Nomura M, Ebisuda Y, Mukai K, Yoshida T.We investigated the risk factors for epistaxis in Japanese flat races over a 20-year period. The veterinary records of horses identified as having epistaxis by endoscopy on the race day, and the official racing records of all flat races from April to September between 2001 and 2020, were reviewed. The racecourses (n = 10), surface type, surface condition, race class, race distance, race year, sex, age, two training centers, ambient temperature, and body weight on race days were assessed using multivariable logistic regression (p < 0.05). Of 475,709 race starts, 616 (1.30 cases per 1000 starts;...
Willink DL, Smeenk LA, van Oijen PW, de Kruif A.In the period 1994-1996 1030 oestruses of Dutch Warmblood mares were evaluated on the incidence of multiple ovulations diagnosed by rectal palpation. Ultrasonography was not used. All follicles > 25 mm were noted. The examination was repeated every 48 hours. The incidence of multiple follicle development was 7.3%. In a group of 50 ultrasonographically diagnosed twin-pregnant mares only 14 (28%) had been detected by rectal palpation as a multiple ovulation. This suggests an incidence of multiple ovulations in Dutch Warmblood mares of 7.3 x 1/28 x 100 = 26%. Restrictions of rectal palpation are ...
Peters JW, de Boer B, Broeze-ten Voorde G, Broeze J, Wiemer P, Sterk T, Spoormakers T.Prevalence of dental disorders in 483 horses and ponies Five equine veterinarians working at three equine referral hospitals examined the oral cavity of 483 horses and ponies prior to surgery, to gain information about the prevalence of common dental disorders in the horse. A thorough examination, using hands/fingers, a full-mouth speculum, a dental mirror and a good light source, is essential to detect such disorders. Many horses examined needed dental attention even though there were no problems with mastication or riding. The most detected abnormalities were sharp enamel points on the bucca...
Weaver MP, Wilant L.A postal survey of the owners of Clydesdale horses in the UK and USA was conducted to obtain information on tarsocrural effusion ('bog spavin') as an indicator of osteochondrosis from 935 horses. Additional information requested included details of how this condition was investigated and treated. The reported tarsocrural effusion incidence was 10 per cent. The majority of respondents believed the condition to be of concern to Clydesdale owners, but only a minority were aware of the implications of tarsocrural effusion, suggesting that owner education would be of benefit.
Goodale EC, White SD, Outerbridge CA, Everett AD, Affolter VK.Hyperaesthetic leucotrichia (HL) rarely affects horses and causes painful lesions on the dorsum that result in leucotrichia. This may be a variant of erythema multiforme (EM), but there are no studies investigating this condition. Objective: Describe the clinical and histological features of HL and compare them to the histological features of EM. Methods: A retrospective review of medical records from 1985 to 2015 identified 15 horses with HL. Thirteen biopsies of HL and five of EM were evaluated and compared. Results: Arabian horses and their crosses (χ(2) (1) = 8.56, P < 0.01) and A...
Hifumi T, Tanaka T, Sato M, Akioka K, Fujimata C, Miyoshi N.Alveolar echinococcosis in slaughtered horses remains a public health issue. This study aimed to develop a Recombinase polymerase amplification (RPA) assay targeting the mitochondrial NADH dehydrogenase subunit 5 () gene of for the rapid detection of equine alveolar echinococcosis. Thirty-six hepatic solid nodules obtained from each horse ( = 36) were evaluated based on histopathological examination and -targeted PCR and then submitted to the RPA assay. The results of the developed RPA assay were 94.4% consistent with those of PCR and Cohen's kappa coefficient value was 0.89 statistically,...
Ferguson JA, Reeves WC, Hardy JL.Serologic studies in 24 ponies indicated that prevaccination antibodies to Venezuelan equine encephalomyelitis (VEE) virus (strain TC-83) had no influence on hemagglutination-inhibition (HI) antibody stimulation by western equine encephalomyelitis (WEE) or eastern equine encephalomyelits (EEE)-WEE vaccines. However, studies of the effects of VEE neutralizing antibodies on neutralizing antibody stimulation by the heterologous alphavirus vaccines were inconclusive. The VEE, WEE, and EEE antibody responses were studied in 18 VEE-vaccinated (strain TC-83) animals (13 ponies and 5 horses) at 9 to 1...
Crowell-Davis SL, Houpt KA.A thorough behavioral history is essential for adequate assessment of a given case. In reviewing the chief complaint, a description of what actually happened, rather than the owner's interpretation of what happened, is required. Other behavior problems, environment, rearing history, and training need to be reviewed. Sample question sets for some common problems are given.
French jockeys suffer more severe injuries when they fall off their horses than their British counterparts. While it has been shown that jockeys suffer high rates of fatal and non-fatal injuries, little is known about differences in injury rates between countries. To investigate this, researchers from Australia, France and the UK used prospectively collected data on the rates of fatal and non-fatal injuries in flat and jump jockeys in France and compared them with data from the UK.
