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.
Daniels RS, Skehel JJ, Wiley DC.The amino acid sequence of the haemagglutinin of A/equine/Miami/63 (H3N8), the prototype influenza virus of the H3 subtype from horses, is deduced from the nucleotide sequence of virus RNA and compared with the sequences of haemagglutinins of viruses of this subtype isolated from humans [X-31 (H3N2)] and from birds [A/duck/Ukraine/63 (H3N8)] and with the sequence of the haemagglutinin of A/equine/Fontainebleau/79 (H3N8) a virus isolated from a recent outbreak of equine influenza. The amino acid sequence differences detected are discussed with reference to the structure of the molecules, their ...
Palmer JE, Whitlock RH, Benson CE, Becht JL, Morris DD, Acland HM.Bacteriologic cultures of 65 rectal mucosal samples and 335 fecal samples from 53 horses and 5 cattle shedding Salmonella were performed. Salmonella spp were isolated from 34 (52%) rectal mucosal samples, 21 (32%) concurrent fecal samples, and 150 (45%) total fecal samples. The use of rectal mucosal samples when compared with concurrently obtained fecal samples significantly (P less than 0.025) improved the ability to isolate Salmonella spp. Concurrent bacteriologic culture of rectal mucosal samples and fecal samples resulted in 39 (60%) isolations. Compared with a series of fecal samples, Sal...
Mitchell CJ, Darsie RF, Monath TP, Sabattini MS, Daffner J.A large net trap was used to sample mosquito populations attracted to horses at three sites each in Santa Fe and Rio Negro Provinces, Argentina, during the austral summer of 1984. These provinces, as well as others in Argentina, were affected by a severe epizootic of western equine encephalitis (WEE) during 1982-83. Totals of 2,752 and 6,929 mosquitoes were collected in Santa Fe and Rio Negro Provinces during five and three trap nights, respectively. Culex mosquitoes of the subgenus Culex were predominant (45.8% of total) in the Santa Fe collections, although Aedes albifasciatus also was preva...
An outbreak of equine viral arteritis in the American state of Kentucky led to a temporary ban being imposed by France, Ireland and the UK on the importation of horses from the USA during 1984. Sporadic cases of influenza caused by the type 2 strain of the virus were confirmed in France throughout the year and cases of strangles in thoroughbred mares and foals were reported from all three countries. No cases of contagious equine metritis were confirmed among the thoroughbred breeding population, although a number of outbreaks of the abortion form of rhinopneumonitis occurred. A small number of...
Crowe MW, Swerczek TW.In a 13-year survey of equine congenital defects that resulted in death or required euthanasia in central Kentucky, necropsies were performed on 608 deformed fetuses or newborn foals. The following congenital anomalies were observed: contracted foal syndrome (33.2%), miscellaneous limb contraction (20%), multiple defects (5.3%), microphthalmia (4.6%), craniofacial malformations (4.3%), cleft palate (4.0%), heart defects (3.5%), umbilical defects (3.5%), and hydrocephalus (3.0%). Eleven less frequently occurring anomalies constituted the balance of the congenital defects in fetuses and newborn ...
Adamson PJ, Wilson WD, Hirsh DC, Baggot JD, Martin LD.In vitro antimicrobic susceptibility patterns of commonly isolated aerobic gram-positive and gram-negative bacterial pathogens of equine origin were determined, using the agar-plate dilution method. All organisms were recent clinical isolates and included Corynebacterium (Rhodococcus) equi, Corynebacterium pseudotuberculosis, (coagulase positive) Staphylococcus sp, Streptococcus equi, Streptococcus zooepidemicus, Actinobacillus sp, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella. In vitro susceptibility levels were outlined for 14 antimicro...
Biberstein EL, Jang SS, Hirsh DC.From 1965 to 1983, Nocardia asteroides infection was diagnosed in 16 horses at the Veterinary Medical Teaching Hospital, University of California, Davis. In 2 of the cases, the infection was traumatic in origin and local in extent; the horses recovered without relevant antimicrobial therapy. Fourteen horses had pulmonary or disseminated infections that ended fatally. All 14 had various degrees of immunosuppression. Of these, 8 were Arabian foals with combined immunodeficiency disease and 3 were aged horses with hyperadrenocorticism secondary to ACTH-secreting pituitary tumors. Of the other 3, ...
Mayr A.Prophylactic immunization of animals against obligat and nonobligat pathogenic zoonoses benefit human health in many ways both directly and indirectly. Typical examples of a direct protective effect are the vaccinations of dogs, cats and foxes against rabies as well as the vaccinations against respiratory diseases in cows, horses, dogs and cats to which the most varied species of pathogens of noncompulsory zoonoses contribute. A considerable contribution to the protection of human health is made by the vaccination against salmonellosis and leptospirosis, against vesicular stomatitis, American ...
Rossdale PD, Hopes R, Digby NJ, offord K.An epidemiological study of wastage among racehorses was conducted in 1982 and 1983 among six stables, five of which were in Newmarket. The basis of the survey was the inability of horses to take part in cantering exercise as a result of injury or disease. The greatest number of days lost to training was caused by lameness (67.6 per cent) and respiratory problems (20.5 per cent). Conditions of the foot (19 pe cent), muscle (18 per cent), carpus (14 per cent), fetlock joints (14 per cent), tendons (10 per cent) and sore shins (9 per cent) were the major reasons for training days being lost in 1...
Robertson-Smith RG, Jeffcott LB, Friend SC, Badcoe LM.The clinical, pathological and epidemiological factors were investigated in 12 horses presenting with severe neurological signs. Although the cases involved differing central (n = 1), spinal cord (n = 4) and peripheral nerve (n = 7) deficits in a number of instances, there were similar pathological findings. The possibility of a unifying aetiological factor, such as a toxicosis, is discussed because of the pathological similarities and as the cases appeared during an unusually long dry period.
Everard CO, Fraser-Chanpong GM, James AC, Butcher LV.Sera from 1,206 livestock animals and chickens on Grenada and Trinidad were tested for leptospiral antibodies by the microscopic agglutination test. 376 of the sera were positive (25% of those tested on Grenada and 44% on Trinidad). The positive sera were obtained from 25% of 324 cattle, 35% of 130 pigs, 35% of 146 sheep, 25% of 44 goats and 11% of 175 chickens on Grenada; and 92% of 26 cattle, 53% of 122 pigs, 76% of 87 horses and donkeys and 11% of 144 chickens on Trinidad. Eight sera from ducks and geese on Trinidad were tested and found to be negative. The serogroups most commonly found to...
Boch J.Babesia infections serologically diagnosed in horses, cattle and dogs in Southern Germany during the last few years are described. 321 sera of horses were examined for specific antibodies to Babesia by means of CFT and IIF in 1984; 18 sera reacted to Babesia equi and 4 to Babesia caballi antigen. In a cattle breeding area in the Western Allgäu 13% of 1616 cattle reacted positive to Babesia divergens antigen using IIF and ELISA; during the grazing season 1982 new latent infections were observed in 25 of 266 calves and heifers. Cases of introduced canine babesiosis are more frequent; 10 of 34 s...
Allen GP, Yeargan MR, Turtinen LW, Bryans JT.From restriction endonuclease characterization of the DNA of 317 isolates of equine abortion virus (equine herpesvirus-1; EHV-1) from 176 epizootically unrelated outbreaks of equine virus abortion occurring over 24 years in Kentucky, an epizootic pattern and variation of the virus have emerged. Two electropherotypes of EHV-1 (1P and 1B) accounted for greater than 90% of the nonvaccine-related abortion isolates examined. From 1960 to 1981, EHV-1 1P was the predominant isolate circulating in the central Kentucky area and the cause of greater than 80% of EHV-1-related abortions. In 1981, the occu...
Varewyck H, Bouquet Y, Lazary S, Guérin G, Van de Weghe A, Van Zeveren A.158 Belgian Saddlebreds, 130 Belgian Trotters, 108 Belgian Draft horses and 92 Shetland ponies have been typed for serologically defined antigens at the ELA and ELY systems. Gene frequencies were estimated in each breed for the internationally established ELA, ELY-1 and ELY-2 alleles as well as for locally assigned additional ELA markers and for subtypes of ELA-W3, W9 and W11. The distribution of ELA alleles was in agreement with the expected Hardy-Weinberg equilibrium for the 4 horse breeds described here. Differences in gene frequencies between these main Belgian horse populations were obser...
Doreau M, Martin-Rosset W.Uraemia variations in the heavy breed mare were studied in different situations. A study with 35 mares during an entire grazing season was conducted. The mean uraemia varied between 48.5 and 67.5 mg/100 ml plasma, with season and type of grass. The highest values were found with first-cycle pasture grass. Uraemia was lower with winter diets: 28.6 to 36.0 mg/100 ml. A study using 15 mares fed isonitrogenous diets based on hay or straw, and concentrates offered two different levels, between two months before and 8 days after foaling, showed that the physiological stage had a very moderate effect...
Khan ZU, Misra VC, Randhawa HS.Prevalence of serum precipitins against Micropolyspora faeni, Thermoactinomyces vulgaris and Aspergillus fumigatus, employing the counterimmunoelectrophoresis (COIE) and Ouchterlony's double diffusion (DD) techniques, is reported in 162 of the equines stationed at two military installations in north-western India. M. faeni specific precipitins were demonstrable in 58 of 112 mules from site I in the mountainous region whereas the results were negative for all of the 50 horses examined from site II located in the plains. Of the 58 M. faeni positive mules, 45 (78%) had signs and symptoms suggesti...
Della-Porta AJ.There has been concern that the present nomenclature system for the members of the Reoviridae family, and particularly the Orbivirus genus, does not represent the actual relationships exhibited between the members. In order to follow the conventions established by the International Committee for the Taxonomy of Viruses (ICTV), it is tentatively proposed that the present Reoviridae genera be upgraded in status to the following sub-families: reovirinae, orbivirinae, Fijivirinae, cypovirinae, rotavirinae, coltivirinae and phytoreovirinae. Below the sub-family level, divisions of genus (equivalent...
Jacob RJ, Price R, Allen GP.Equine herpesvirus type 3 (EHV-3) DNA, isolated from purified virions of the large-plaque strain, was digested with the restriction endonucleases XbaI, Bg/II, EcoRI, and HindIII. Several lines of evidence indicated that the DNA extracted from purified virions was composed of long (L) and short (S) components and was present as two isomeric forms, P and IS. The evidence included: (i) after electrophoresis on agarose gels, the summed molecular weights of the digestion products exceeded that expected from intact, unit size DNA; (ii) quantitative measurements of radioactivity (molar ratios) indica...
Osiyemi TI, Synge EM, Agbonlahor DE, Agbavwe R.Toxoplasma gondii antibodies were found in the sera of 22.86% of people in the Jos area of Plateau State, Nigeria. The incidence of antibodies in Nigerian food animals was 17.40%, the highest being in sheep (21.92%) and lowest in goats (13.88%). Cattle and horses were roughly equally infected--about 17.0%. The zoonotic potential of T. gondii in food animals is stressed and epidemiological factors are reviewed.
Mettler NE, Fernández AS, Di Santo MI, Pardo DA.Sera from 282 equines from Tandil country and surroundings were investigated searching for hemagglutination inhibition (HI), Complement fixation (CF), and Neutralizing (NT) antibodies against three flavivirus:Ilheus, St. Louis Encephalitis, and Yellow Fever from the Togaviridae family. Sera were collected between 3-20-79 and 11-25-80 from 10 different places in Tandil and Ayacucho countries. Animals ranged from 45 days to 27 years old. Forty nine of them reacted with one or more flavivirus by HI and/or CF tes representing a prevalence of 17.4% for this antigenic complex. Twenty four of them ne...
Neill JD, Kelling CL, Rhodes MB.Pigs experimentally inoculated with bovine herpesvirus-1 or equine herpesvirus-1 developed mild clinical disease signs. Regression of clinical disease was accompanied by development of specific virus-neutralizing antibodies. These antibodies did not react positively with pseudorabies antigens in the serum-virus neutralization test, an indirect radioimmunoassay, or a microimmunodiffusion test.
Bisgaard M, Piechulla K, Ying YT, Frederiksen W, Mannheim W.Evidence was obtained to indicate that equine strains of organisms previously described as Actinobacillus suis or hemolytic variants of Actinobacillus equuli might constitute a separate group of organisms provisionally designated taxon 11. Four biovars were noticed within taxon 11. Selected DNA:DNA hybridizations support the classification of the mannitol positive biovar 2 of taxon 11 distinct from porcine A. suis. The final taxonomical position of taxon 11, however, has to await more detailed genetic studies including all biovars of taxon 11. A species name has not been suggested for the same...
Hird DW, Pappaioanou M, Smith BP.In an investigation of a 1981-1982 outbreak of nosocomial Salmonella saintpaul infection in hospitalized horses at the University of California Veterinary Medical Teaching Hospital in Davis, California, a case-control study was performed using data gathered from the records of 33 cases and 132 controls. Multiple logistic regression risk analysis was used to identify factors associated with isolation of the organism, controlling for the effects of other, possibly confounding variables. Horses receiving parenteral antibiotics were at 10.9 times greater risk of having S. saintpaul isolated than w...
Pounder DJ.The fatalities associated with the riding and handling of horses in South Australia over the 11-year period 1973-1983 are reviewed. There were 18 deaths, including two sudden natural deaths in the saddle and one drowning. The 15 cases of horse-related trauma represent a death rate of approximately one per million population per annum. Thirteen of the deaths were the result of a head injury after a fall. Nine persons were not wearing protective headgear. The two principal groups at risk were male professional riders with a mean age of 32 years and female amateurs with a mean age of 19 years.
Ilgren EB, Teddy PJ, Vafadis J, Briggs M, Gardiner NG.We present a clinical and pathological study of brain injuries in horse-riding accidents. Among six fatal cases, all experienced riders varying in age and sex, two were not wearing helmets and four had inadequate protective headgear. Among five non-fatal cases, four wore adequate helmets and only one of these suffered permanent neurological damage. The fifth was not wearing a helmet and although he eventually returned to work, a CT scan following the fall showed a deep-seated perithalamic hematoma. These findings are consistent with those of virtually all other studies in that they suggest tha...
Strang C.Camilla Strang of the Animal Health Trust provides an overview of the diagnosis and control of conditions associated with infection by equine herpesvirus.
Anthony ND.The clinical signs of horses infected with equine influenza in two Queensland locations, Morgan Park Recreational Grounds at Warwick, and the western region of Brisbane, are described and compared. Clinical signs were observed to be more severe, and treatment more intensive, in horses in stressful settings.