Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Epidemiology
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.
Phagocytic and killing capacities of uterine-derived polymorphonuclear leukocytes from mares resistant and susceptible to chronic endometritis. The host defense competence of uterine-derived polymorphonuclear leukocytes (PMN) from mares considered resistant (grade I uteri) and susceptible (grade III uteri) to chronic endometritis was evaluated for phagocytic and killing (bactericidal) capacities, using a fluorochrome assay. Peripheral blood PMN from noncategorized mares and from grade I and grade III mares were used as controls. Uterine-derived PMN from mares with grade I uteri were functionally competent for phagocytosis and killing of Candida albicans, whereas uterine-derived PMN from mares with grade III uteri had significantly les...
Arbovirus investigations in Argentina, 1977-1980. IV. Serologic surveys and sentinel equine program. Serologic surveys of wild and domestic birds, wild mammals, and horses were conducted during arbovirus field studies in Argentina from 1977 through 1980, a non-epizootic interval. The prevalence of neutralizing antibodies to eastern equine encephalitis (EEE) was consistently higher than to western equine encephalitis (WEE) virus in all species and all areas. The presence of antibodies in short-lived avian species and in young unvaccinated horses and the demonstration of seroconversions in horses during the period, indicated that these viruses are either enzootic in, or annually reintroduced in...
Arbovirus investigations in Argentina, 1977-1980. I. Historical aspects and description of study sites. This is the introductory paper to a series on the ecology of arboviruses in Argentina. Epizootics of equine encephalitis have occurred since at least 1908, principally in the Pampa and Espinal biogeographic zones, with significant economic losses; human cases of encephalitis have been rare or absent. Both western equine and eastern equine encephalitis viruses have been isolated from horses during these epizootics, but the mosquitoes responsible for transmission have not been identified. A number of isolations of Venezuelan equine encephalitis (VEE) virus were reported between 1936 and 1958 in ...
Persistence of encysted Toxoplasma gondii in tissues of equids fed oocysts. Thirteen 6-month- to 13-year-old equids were each inoculated orally with 10,000 infective Toxoplasma gondii oocysts. The equids remained clinically normal. Equids were euthanatized on postinoculation days 33, 45, 90, 104, 120, 140, 162, 183, 197, 204, 211, 294, and 476. Their tissues were bioassayed for viable oocysts by feeding muscles to Toxoplasma-free cats and by inoculation of pepsin digests of 13 organs into mice. Using mouse inoculation, T gondii was recovered from tissues of the 9 equids euthanatized on each of postinoculation days 33, 45, 120, 140, 183, 197, 211, 294, and 476. Toxopla...
Salmonella shed by horses with colic. Salmonella was isolated from 13 of 100 colicky horses admitted to a referral hospital. Seven horses were shedding the microorganism at or soon after hospital admission. A unique serotype was introduced into the hospital by a horse not shedding Salmonella at admission. It was concluded that 8 horses were infected before admission. Whether the remaining 5 horses were infected before or after admission could not be determined. Salmonella senftenberg was the most commonly isolated serotype from colicky horses and from horses with salmonellosis that were not colicky on hospital admission during the...
Serum bactericidal responses to Streptococcus equi of horses following infection or vaccination. An indirect test based on horse blood was used to study bactericidal responses of the horse to Streptococcus equi following infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to...
Endocarditis in six horses. Six horses (five males) aged three months to fourteen years had endocarditis at necropsy. Two of the horses had a clinical diagnosis of valvular endocarditis with negative blood cultures. Single or complex valvular involvement was present in five horses. One horse had non-infectious thrombi associated only with the chordae tendineae. Mitral valves were affected in four horses, and aortic semilunar valves were affected in two. Infarcts had occurred in the kidneys and the myocardium of four horses. Bacteria were isolated postmortem from the valvular vegetations of two horses; Candida parapsilosi...
A review and some observations on stringhalt. A review of the literature on stringhalt in horses is presented, including the aetiology, clinical signs, pathology and treatment of this disease. Three New Zealand outbreaks of stringhalt are reported and discussed. The occurrence of these (and most previously reported outbreaks) in the late summer and autumn, and the association of the disease with various weeds, indicates a likely toxic aetiology.
Equine leucocyte antigens in sarcoid-affected horses. The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
Antibodies against equine herpesvirus 1 in the cerebrospinal fluid in the horse. Neutralizing antibodies against equine herpesvirus 1 were measured in serum and cerebrospinal fluid of 16 horses and ponies from a closed herd both before and after vaccination with modified live equine herpesvirus 1. These titers were also measured in 22 neurologically normal and 15 neurologically abnormal horses at a teaching hospital. Animals from the closed herd had prevaccination serum titers up to 1:8 and postvaccination serum titers up to 1:128. Horses from the teaching hospital had serum titers up to 1:64. Cerebrospinal fluid titers were not detected in the vaccinated horses or the neu...
Embryonic loss in mares: Incidence and ultrasonic morphology. Pregnancy was determined by ultrasound on Days 11, 15, 20, 25, 30, 35, 40, 45, and 50 in 154 ponies and 27 horses. In ponies, the embryonic loss rate for Days 11 to 15 (28 154 , 18.2%) was greater (P<0.01) than for any of the subsequent five-day intervals (0% to 3.3%). There were no losses during Days 11 to 15 in horses (0 27 ), and the difference between ponies and horses was significant. The loss rates for the seven periods encompassing Days 15 to 50 were not significantly different among periods. Pseudopregnancy occurred more frequently (P<0.01) following embryonic loss after Day 20 (...
Toxoplasma seroprevalence in animals in northern India. In a serological survey of latent Toxoplasma prevalence on 3761 animals in northern India by the microtitre indirect haemagglutination test, 23.7 per cent were found to have antibody titres ranging from 1:4 to 1:1024. Seropositivity was recorded in 25.3 per cent of 1227 sheep, 30.3 per cent of 961 goats, 11.8 per cent of 603 horses, 19.3 per cent of 243 cattle, 15.7 per cent of 108 water buffaloes, 31.5 per cent of 178 pigs, 30.9 per cent of 175 dogs, 33.7 per cent of 80 cats and in 9.7 per cent of 186 bandicoot rats. Relevant epidemiological data has been furnished. High seropositivity in foo...
Prevalence of equine onchocerciasis in southeastern and midwestern United States. Of 664 horses reported to have originated in southeastern and midwestern United States, 341 (51.4%) were positive for Onchocerca cervicalis cutaneous microfilariasis. The highest prevalence of 68.8% was recorded for horses from Virginia. Horses with the highest concentrations of microfilariae (as high as 19,770 microfilariae/mg in 1 horse) were from the Southeast (Georgia, Florida, Tennessee, and Alabama). For horses from South Carolina, the prevalence of infection was 57.1%; from the Midwest (Kentucky, Illinois, Ohio, and Indiana), 54.4%; from North Carolina, 45.5%; from Pennsylvania, 7.7%; a...
Haemorrhagic necrotising enteritis in foals associated with Clostridium perfringens. Two foals aged 35 and 48 h from 2 Thoroughbred studs died several hours after developing clinical signs of depression, severe haemorrhagic diarrhoea and dehydration. Both foals had an acute haemorrhagic enteritis extending from the anterior jejunum to the terminal ileum which was characterised histologically by villus necrosis. Necrotic villi were surrounded by large numbers of rod-shaped Gram positive bacteria. Clostridium perfringens was recovered from the intestines of both foals and the isolates were considered to be C. perfringens type C. Other cases of diarrhoea were also observed in foa...
Studies on histoplasmosis farciminosi (epizootic lymphangitis) in Egypt. Isolation of Histoplasma farciminosum from cases of histoplasmosis farciminosi in horses and its morphological characteristics. Isolation of Histoplasma farciminosum from five horses, showing typical signs of histoplasmosis farciminosi (epizootic lymphangitis) was successfully attempted. The mycelial form of H. farciminosum was isolated on Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion (BHI) agar enriched with 10% horse blood and PPLO dextrose glycerol agar. The last medium proved to be the most effective, both for primary isolation and subculturing of the fungus. It was found that on primary isolation, the lag phase of the mycelial form of the fungus was relatively long, involving 4-8 weeks ...
Head protection for horse riders: a cause for concern. We report the frequency with which horse riders with a significant head injury present to a large accident and emergency department. We have also recorded details about the use of headwear and conclude that horse-riding is associated with a serious risk of head injury and 'protective' headwear may not always protect.
Neoplasms of equidae in Iran. THE results of a 20 year retrospective study of the tumours diagnosed in all equine cases referred to the Faculty of Veterinary Medicine, University of Teheran, for surgical treatment or post mortem examination are reported here.
Seasonal changes in pasture infectivity by equine cyathostomes in north central Florida. ALTHOUGH the seasonal transmission of equine cyathostomes is well documented in cool climates (Ogbourne 1978),
less is known about their transmission in warm climates.
Australian studies have suggested that these parasites do not
survive well during the long, hot summers of the humid
subtropics (English 1979a.b). Development of egg to third
stage larva (L3) was rapid during the summer but the
percentage of larvae that survived to ascend herbage was very
low. In contrast, larvae survived for longer periods during the
cooler months and the highest L3 populations were observed
during spr...
Observations of tabanid feeding on mares and foals. The occurrence of tabanid feeding between mares and foals was observed. When mares and foals were observed freely moving within a pasture situation, foals had 2.43% (4 flies in 77 observations vs 297 flies in 139 observations) of the tabanid feeding occurrences of the mares. This difference in tabanid burden varied due to herd size, herd location, and tabanid species. Lower tabanid burden of foals was indicated as a practical protective mechanism against pathogenic agents mechanically transmitted by tabanids, such as equine infectious anemia virus.
Prevalence and epidemiology of the major gastrointestinal parasites of horses in Perth, Western Australia. A survey was conducted on the prevalence of the major gastrointestinal parasites in 140 horses necropsied in Perth, Western Australia, during 1979 to 1982. Adult Strongylus vulgaris were found in 22.5 per cent of horses and verminous arteritis in 62.9 per cent. The peak worm prevalence was in November to January (summer). S edentatus had a similar prevalence and seasonality but S equinus was not found in this survey. Draschia megastoma and Habronema muscae were found in 66.2 per cent and 35.3 per cent of horses respectively. Infection is probably acquired in summer when 8 per cent of the Musca...
Prospective study of progeny of inapparent equine carriers of equine infectious anemia virus. Progeny of a band of horses, positive by the agar-gel immunodiffusion (AGID) test for equine infectious anemia (EIA) antibody, were observed through their weaning over a 4-year period. Sentinels (AGID test-negative) were allowed to mingle with EIA-infected mares and their foals in pasture situations in an area with high populations of potential vectors. Of 27 adult sentinels, 8 (30%) seroconverted in annual rates ranging from 0% to 75%. In contrast, only 2 of 31 (6%) foals weaned became infected. Difference in infection rates between adult sentinels and foals was significant (chi 2, P less tha...
Nonimmune binding of equine immunoglobulin by the causative organism of contagious equine metritis, Taylorella equigenitalis. This study identifies nonimmune binding of equine immunoglobulin by the causative organism of contagious equine metritis. Immunoglobulin binding to the bacterium was strongest for immunoglobulin G (IgG) and less for IgM; IgA was not bound. Binding of equine IgG was inhibited by human IgG, but not by IgG of domestic animals. Immunoglobulin binding by the bacterium appeared to be directed towards an epitope in the hinge region of the immunoglobulin molecule.
[Mechanism of distribution of Strongyloidea larvae among ungulate animals at pasture]. The problem of dissimilation of larvae of strongylates of ruminants in pasture biocoenosis is discussed. A new form of their migration in horizontal direction on the basis of negative geotaxis is suggested. As a result of alternation of vertical migration of larvae on the tilting leaves of the grass and their subsequent washing off with rain or dew down on the ground proceeds their distribution on the pasture. The description of corresponding experiments is given.
