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.
The seroprevalence of equine trypanosomosis in the pantanal. Since little information is available on the epizootiological status of Trypanosoma evansi in South America and particularly Brazil, we evaluated equine serum samples collected in 1993, 1994, 1995 and 1997 for the presence of antibodies against this trypanosome species. Our study shows corroborative evidence about the correlation among high T. evansi seroprevalence and the rainy season in the Pantanal, Brazil. The higher seroprevalence was 79.2% in horses from a ranch located in the Nhecolândia sub-region in 1994 and the lower 5.8% in animals from the same ranch in 1997. No seroprevalence was...
Biochemical fingerprinting and ribotyping of isolates of Actinobacillus equuli from healthy and diseased horses. A total of 112 isolates of Actinobacillus equuli, including both clinical isolates and isolates from the oral cavity of healthy horses, were included in this study. All isolates were ribotyped and 92 of the isolates were also typed biochemically, with the commercially available Pheneplate (PhP) system, which includes 48 different substrates. As expected, ribotyping was more sensitive than biochemical fingerprinting in detecting differences between the isolates. The correlation between the two methods used was poor. It was not possible to distinguish clinical isolates from normal flora isolates...
Are Sarcocystis neurona and Sarcocystis falcatula synonymous? A horse infection challenge. Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease of the horse. The causative agent. Sarcocystis neurona, has been suggested to be synonymous with Sarcocystis falcatula, implying a role for birds as intermediate hosts. To test this hypothesis, opossums (Didelphis virginiana) were fed muscles containing S. falcatula sarcocysts from naturally infected brown-headed cowbirds (Molothrus ater). Ten horses were tested extensively to ensure no previous exposure to S. neurona and were quarantined for 14 days, and then 5 of the horses were each administered 10(6) S. falcatula...
Multiple DNA markers differentiate Sarcocystis neurona and Sarcocystis falcatula. Studies designed to investigate the causative agent of equine protozoal myeloencephalitis and its life cycle have been hampered by the marked similarity of Sarcocystis neurona to other Sarcocystis spp. present in the same definitive host. Random-amplified polymorphic DNA techniques were used to amplify DNA from isolates of S. neurona and Sarcocystis falcatula. DNA sequence analysis of polymerase chain reaction (PCR) products was then used to design PCR primers to amplify specific Sarcocystis spp. DNA products. The ribosomal RNA internal transcribed spacer was also amplified and compared betwee...
Aetiopathogenesis of parasagittal fractures of the distal condyles of the third metacarpal and third metatarsal bones–review of the literature. Fractures are the cause of considerable morbidity and mortality among Thoroughbred racehorses. A significant proportion of these injuries occur in the absence of any particular traumatic incident. Evidence of prefracture pathology interpreted as fatigue damage has been identified in some such cases, but the aetiology of many of these so-called 'spontaneous' fractures remains obscure. Parasagittal fractures of the third metacarpal (McIII) and third metatarsal (MtIII) bones are one of the more common fractures to affect Thoroughbred racehorses. The configuration of each of these fracture types i...
Thoracic trauma in newborn foals. In a report describing life ending fractures (255 horses) from the Livestock Disease Diagnostic Center, Kentucky (1993 and 1994), 32 foals had rib fractures. The purpose of our study was to examine the incidence of rib fractures in newborn foals on a Thoroughbred studfarm by physical and radiographic examination, to determine factors which may contribute to the problem and to document any clinical consequences. All foals (263) included were examined within 3 days of birth. The thoracic cage was palpated externally for abnormalities and all foals were placed in dorsal recumbency to evaluate tho...
Equine glanders in Turkey. In the course of an epidemiological study of glanders on a number of Turkish islands in the Sea of Marmara, 1128 horses were examined by using the intracutaneous mallein test. Thirty-five (3-1 per cent) developed an increase in rectal temperature and a swelling at the point of injection. Ten of these horses were killed and glanders was confirmed in five cases by the presence of lesions and by the immunohistological demonstration of the causative agent, Burkholderia mallei. Clinical and pathological findings indicated that in all cases the infection was restricted to the mucous membrane of the ...
Fumonsin B1, B2, and B3 content of commercial unprocessed maize imported into South Africa from Argentina and the USA during 1992. The widespread occurrence of F. moniliforme and the toxic effects of its secondary metabolites, the fumonisins B1(FB1), B2(FB2) and B3(FB3), make it imperative that fumonisin contamination of maize, a major constituent of animal feed as well as the staple diet of many populations, be closely monitored to reduce the risk of fumonisin exposure. Equine leukoencephalomalacia and porcine pulmonary oedema have been associated with the intake of feed heavily contaminated with fumonisins. In addition, high levels of fumonisins in the maize-based staple diets of certain populations have been linked to ...
Role of interferon and interferon regulatory factors in early protection against Venezuelan equine encephalitis virus infection. To investigate the role of type I interferon (IFN) and its regulatory transacting proteins, interferon regulatory factors (IRF-1 and IRF-2), in early protection against infection with virulent Venezuelan equine encephalitis virus (VEE), we utilized mice with targeted mutations in the IFN-alpha/beta receptor, IRF-1, or IRF-2 genes. IFN-alpha/beta-receptor knockout mice are highly susceptible to peripheral infection with virulent or attenuated VEE, resulting in their death within 24 and 48 h, respectively. Treatment of normal macrophages with anti-IFN-alpha/beta antibody prior to and during infe...
Subconjunctival haemorrhages in neonatal thoroughbred foals. A survey of 169 neonatal thoroughbred foals revealed that 8.3 per cent had subconjunctival haemorrhages, but there was no indication of a relationship between retinal and subconjunctival haemorrhages. The haemorrhages were not related to any abnormality of the foals and there was no sex or eye predisposition. In most cases the haemorrhages were fresh and red, occurred mainly dorsally or dorsonasally and extended up to the limbus; they resolved completely within four to 10 days, depending on their initial severity and extent. They had no effect on the foals' vision in the short or long term. Th...
Molecular epidemiological studies of veterinary arboviral encephalitides. Recent studies using molecular genetic approaches have made important contributions to our understanding of the epidemiology of veterinary arboviral encephalitides. Viruses utilizing avian enzootic hosts, such as Western equine encephalitis virus (WEEV) and North American Eastern equine encephalitis virus (EEEV), evolve as relatively few, highly conserved genotypes that extend over wide geographic regions; viruses utilizing mammalian hosts with more limited dispersal evolve within multiple genotypes, each geographically restricted. Similar findings have been reported for Australian alphaviruse...
Methicillin-resistant Staphylococcus aureus outbreak in a veterinary teaching hospital: potential human-to-animal transmission. During a 13-month period, 11 equine patients visiting a veterinary teaching hospital for various diagnostic and surgical procedures developed postprocedural infections from which methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA) strains were isolated. The S. aureus isolates were identified by conventional methods that included Gram staining, tests for colonial morphology, tests for clumping factor, and tests for coagulase and urease activities and were also tested with the API STAPH IDENT system. Antimicrobial susceptibility tests were performed by the disk diffusion method. The b...
Genetic divergence with emergence of novel phenotypic variants of equine arteritis virus during persistent infection of stallions. The persistently infected carrier stallion is the critical natural reservoir of equine arteritis virus (EAV), as venereal infection of mares frequently occurs after breeding to such stallions. Two Thoroughbred stallions that were infected during the 1984 outbreak of equine viral arteritis in central Kentucky subsequently became long-term EAV carriers. EAV genomes amplified from the semen of these two stallions were compared by sequence analysis of the six 3' open reading frames (ORFs 2 through 7), which encode the four known structural proteins and two uncharacterized glycoproteins. The major ...
Genetic and phenotypic changes accompanying the emergence of epizootic subtype IC Venezuelan equine encephalitis viruses from an enzootic subtype ID progenitor. Recent studies have indicated that epizootic Venezuelan equine encephalitis (VEE) viruses can evolve from enzootic, subtype ID strains that circulate continuously in lowland tropical forests (A. M. Powers, M. S. Oberste, A. C. Brault, R. Rico-Hesse, S. M. Schmura, J. F. Smith, W. Kang, W. P. Sweeney, and S. C. Weaver, J. Virol. 71:6697-6705, 1997). To identify mutations associated with the phenotypic changes leading to epizootics, we sequenced the entire genomes of two subtype IC epizootic VEE virus strains isolated during a 1992-1993 Venezuelan outbreak and four sympatric, subtype ID enzootic...
Genetic analysis of three South African horse breeds. Genetic variability at 7 blood-group and 10 biochemical genetic loci was examined in 3 South African horse breeds, the Nooitgedacht, Boerperd and Basuto Pony. Observed heterozygosity for these breeds was intermediate for domestic horses, with the highest heterozygosity in the Boerperd and the lowest in the Basuto Pony. The 3 breeds show greater genetic similarity to each other than to other domestic horse breeds. Compared to other breeds, the South African breeds show greater genetic similarity to breeds such as the Thoroughbred, Holstein, Trakehner and Hanovarian and also to North American br...
The circumstances surrounding the outbreak and spread of equine influenza in South Africa. Equine-2 influenza A virus (H3N8) infection first occurred among naïve horses in South Africa in December 1986. The virus was introduced following the importation of six horses from the United States of America. While the release of in-contact horses from quarantine three days after the arrival of these six horses played a role in the rapid spread of the disease in South Africa, other outbreaks of disease were associated with viral introduction by personnel or contaminated instruments. The control measures and implications of the introduction of equine influenza to South Africa are also discu...
Evaluation of temporal and spatial clustering of horses with Corynebacterium pseudotuberculosis infection. To determine whether horses with Corynebacterium pseudotuberculosis infections that were examined at a veterinary medical teaching hospital between July 1, 1992, and June 30, 1994 had patterns of temporal or spatial clustering. Methods: 134 case and 800 control horses randomly selected from all non-case horses admitted during the study period. Methods: Admission date and geographic location were determined. Scan, Cuzick & Edwards', and Knox tests were applied to determine whether case horses had patterns of temporal or spatial clustering. Results: For all windows > or = 3 days (134 case...
Pulmonary aspergillosis in horses: 29 cases (1974-1997). To analyze medical records and identify factors that veterinarians can use to prevent pulmonary aspergillosis in horses or that would enable them to diagnose it as early as possible. Methods: Retrospective study. Methods: 29 horses. Methods: Medical records were reviewed for horses with pulmonary aspergillosis diagnosed on the basis of characteristic postmortem findings. Information on history, clinical signs, disease progression, and postmortem findings was obtained. Results: 25 of 29 (86.2%) horses had primary (n = 20) or secondary (5) disease compatible with loss of integrity of the gastroi...
Genetic diversity of equine arteritis virus. Equine arteritis viruses (EAV) from Europe and America were compared by phylogenetic analysis of 43 isolates obtained over four decades. An additional 22 virus sequences were retrieved from GenBank. Fragments of the glycoprotein G(L) and the replicase genes were amplified by RT-PCR, prior to sequencing and construction of phylogenetic trees. The trees revealed many distinctive lineages, consistent with prolonged diversification within geographically separated host populations. Two large groups and five subgroups were distinguished. Group I consisted mainly of viruses from North America, whilst...
Transmissibility from horses to humans of a novel paramyxovirus, equine morbillivirus (EMV). Determination of potential infectivity of a new paramyxovirus equine morbillivirus (EMV) from horses to humans and humans to humans as a result of two outbreaks in Queensland which involved 23 horses and three humans. Methods: Seroepidemiological testing using neutralizing and immunofluorescing antibodies on people with variable levels of exposure to infected horses and humans. Results: All serological testing on a total of 298 individual contacts was negative. Conclusions: While the three human cases of EMV were probably infected as a result of very close contact with horses, these data sugge...
[Use of a fast test to detect rotavirus in feces]. The commercially available immunoassay "OnSite Rotavirus" was used for the detection of animal rotaviruses in 113 faecal samples. The sensitivity of the test was 88% and the specificity 96% compared with reference methods (EIA, EM). This test would detect approximately 4.4 x 10(6) to 1.8 x 10(7) virus particles per ml. The presence of virus could be demonstrated in fresh faecal samples from cattle, horses and pigs within a few minutes. The rotaviruses of group A were identified independently of the virus serotype. Further results and additional problems of using this test kit are described.
Prevalence of Surra among camels and horses in Jordan. The prevalence of Trypanosoma evansi infection among camels and horses in Jordan was studied using thick blood smears and inoculation techniques with mice and rats. A total of 437 camels and 83 horses from four climatic zones were surveyed. In addition, 40 donkeys, 32 cattle and 35 goats in contact with infected camels and horses were also tested in the same way. Clinical disease was evident in 8.2% of the camels (36 out of 437) and in 9.6% of the horses (8 out of 83). Infection was limited only to the Sweama area on the Dead Sea (within the warm desert-climatic zone), with prevalence of 30.5%...
[Veterinary recommendations for the handling of equine virus arteritis (EVA) in practical breeding care]. The equine virus arteritis (EVA) consistently epidemically varying throughout the different breeds of the horse breeding countries is up to now only of lower significance by means of the typical clinical manifestation as well as an abortion causing factor. The susceptibility of the sexual mature stallions against the equine arteritis virus (EAV) causes different infection response which may lead to some restrictions in their use in natural breeding especially in the artificial insemination. In a certain not precisely predictable part of the stallion population EAV infection will cause a transi...
A longitudinal study of racing thoroughbreds: performance during the first years of racing. To develop a profile of the racing careers of Thoroughbred horses in south-eastern Queensland, and to examine factors that affect racing during the first years of racing. Methods: A longitudinal study using the racing records of a defined cohort of Thoroughbred horses that were born on or within 12 months following 1 August 1991. Data collection commenced in 1996 and will continue until all horses cease racing. In this paper two measures of performance were examined: race earnings during the first year of racing and cumulative proportion of horses still racing up to 2 years after their first s...
Description and morphometric analysis of the eggs of Anopheles (Anopheles) vestitipennis (Diptera: Culcidae) from southern Mexico. Light and scanning electron microscopy were used to compare the eggs of Anopheles vestitipennis Dyar & Knab females collected from human and animal baits in 9 villages of southern Mexico. An. vestitipennis eggs are boat-shaped, with lateral floats extending the length of the egg. Both the deck and dorsal surface are covered with hexagonal and pentagonal chorionic cells that contain round tubercles in the cell field. Crowns that enclose 3-5 lobed tubercles are present at both egg poles. By light microscopy, the mean length/width ratio of eggs of females caught at human bait were statistical...
Diversity of isolates of Rhodococcus equi from Australian thoroughbred horse farms. Pulsed field gel electrophoresis of restriction endonuclease digested genomic DNA from a collection of clinical isolates of Rhodococcus equi was used to compare strain diversity on different Thoroughbred horse farms over time. Restricted diversity was found among the isolates tested, as the same strains were detected on multiple farms and in multiple years. Marked variation occurred in strain prevalence with some strains being represented by single isolates, and the most prevalent by 26 isolates. There were dominant strains on some farms and the prevalence of some strains differed between farm...
Heritability of recurrent exertional rhabdomyolysis in Thoroughbred racehorses. To determine the likely mode of inheritance and identify probable foundation horses for recurrent exertional rhabdomyolysis (RER) in Thoroughbred (TB) racehorses. Methods: 4 families of TB racehorses with a high prevalence of RER, consisting of 3 to 53 horses/family, were used to determine mode of inheritance. Sixty-two TB horses with RER and 34 control TB racehorses without RER were used to identify probable foundation horses for the RER trait. Methods: RER was diagnosed by a veterinarian and verified by detecting high serum creatine kinase activity. Pedigrees dating from 1930 for all horses ...
[Detection of equine arteritis virus (EAV) in stallions–a contribution to the improvement of EAV diagnosis]. Serum samples from 72 stallions were examined for the occurrence of antibodies against equine arteritis virus, of which 41 animals (57%) were found to be positive. 32 of the seropositive stallions were then screened for persistent EAV infection, before and after the breeding season. Semen samples were investigated by RT-PCR followed by dot blot hybridization and nested PCR, and by virus isolation on cell cultures as well. The carrier state was virologically confirmed in 11 of 32 stallions (34%) during the first and in 9 of 20 (45%) during the second investigation. RT-PCR followed by confirmato...
