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Topic:Serology
Serology in horse research involves the study and analysis of blood serum to detect the presence of antibodies or antigens associated with infectious diseases and other health conditions. It is a diagnostic tool used to identify immune responses to pathogens, vaccination status, and exposure to specific diseases. Serological tests in equine research can include enzyme-linked immunosorbent assays (ELISA), complement fixation tests, and virus neutralization tests. These tests help in understanding the epidemiology of diseases, monitoring herd health, and informing vaccination strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and implications of serological testing in equine medicine.
Isolation of Cache Valley virus and detection of antibody for selected arboviruses in Michigan horses in 1980. Blood samples collected in September and November 1980 from 87 horses in southwestern Michigan were examined for virus isolation and for plaque-reduction neutralizing antibody against selected arboviruses. Cache Valley virus was isolated from the blood of a clinically normal horse in St Joseph County in September. The age-specific antibody prevalence for Cache Valley virus indicated enzootic transmission in the study area. The high antibody prevalence and the lack of age-specific antibody prevalence indicated sporadic, but intense, exposure to Jamestown Canyon virus. Low prevalences of antibod...
Serological and virological investigations of an equid herpesvirus 1 (EHV-1) abortion storm on a stud farm in 1985. An extensive outbreak of EHV-1 abortions occurred on a stud farm in England in 1985. Of the 67 pregnant mares present on the stud farm, 31 were challenged with EHV-1, resulting in the loss of 22 fetuses or foals. Laboratory investigations revealed that the spread of the virus closely followed movement of apparently healthy mares (during the incubation period of the infection). During the outbreak mares were challenged 1-4 months before the expected foaling date. There was no relationship between the gestational age at the time of challenge and the subsequent outcome of infection in terms of ab...
A short, reliable, highly reproducible complement fixation test for the serological diagnosis of contagious equine metritis. A complement fixation test, using round-bottomed microtitration plates and an 8 channel microdiluter, based on that used for brucellosis by Herr, Huchzermeyer, Te Brugge, Williamson, Roos & Schiele, 1985, has been developed for use on the sera of horses to detect antibodies to the contagious equine metritis organism. The results with 2 known positive sera tested 116 times in 27 separate tests were reproducible for the most part within a twofold range. They seldom exceeded these limits and never exceeded a fourfold range. The test itself is capable of being carried out within 90 min. The test w...
Attempted transmission of Ehrlichia risticii by field-captured Dermacentor variabilis (Acari: Ixodidae). The capability of field-collected American dog ticks, Dermacentor variabilis, to infect horses with Ehrlichia risticii, causative agent of Potomac horse fever (PHF), was examined by allowing adult ticks collected from horse farms with a history of PHF to feed on susceptible horses. More than 500 male and female ticks attached and fed on 3 test horses; however, no clinical or serologic evidence of PHF was observed in treated or control horses. All horses were challenge exposed with E risticii-infective blood by inoculation at 60 to 65 days after ticks fed, and all developed clinical PHF with su...
Transmissibility and abortogenic effect of equine viral arteritis in mares. A group of 14 pregnant mares was exposed via contact to 4 mares bred to stallions infected with equine viral arteritis virus. There was a demonstrable febrile response in each donor mare and in 12 of the pregnant mares. All 18 mares became seropositive after exposure. Equine viral arteritis virus was isolated from the nasopharynx of 5 pregnant mares, but not from the donor mares. Ten of the pregnant mares aborted, and virus was isolated from fetal specimens or placenta of 8.
Observations on the long term effects of Brucella abortus infection in the horse, including effects during pregnancy and lactation. Five mares and a stallion were studied from three to 30 months after experimental infection with Brucella abortus strain 544. The mares bred normally. No organisms were recovered from horses or from pregnant Friesian heifer contacts. Titres of serum antibody in the antiglobulin (Coombs) and complement fixation tests fell more slowly than those assessed by other tests. The serum of one foal yielded maternal antibody. An intradermal test was positive in infected adults only, and negative in all foals.
Respiratory disease in foals and the epizootiology of equine herpesvirus type 2 infection. The epizootiology of equine herpesvirus type 2 (EHV-2) infection was investigated in Thoroughbred foals on a stud farm which in previous years had suffered economic loss due to respiratory disease. Sixteen pairs of foals and their dams were selected for this study and all of the foals became infected with EHV-2 by two to four months of age. These animals responded serologically to the virus infection as detected by an enzyme-linked immunosorbent assay (ELISA). EHV-2 infection persisted in these foals for two to six months with constant or intermittent virus recovery. This persistent infection ...
Preliminary characterisation of torovirus-like particles of humans: comparison with Berne virus of horses and Breda virus of calves. Pleomorphic virus-like particles have been observed by electron microscopy in the faeces of children and adults with diarrhoea. Some of these particles were approximately 100 nm in diameter and had a "fringe" of closely applied peplomers approximately 10 nm long; they closely resembled Berne virus of horses and Breda virus of calves, the two representatives of a newly proposed family called the Toroviridae. In one sample a toroidal nucleoprotein-like structure was observed within the particles. For two samples a buoyant density of 1.14 g/ml was determined by centrifugation through a sucrose de...
Experimental Babesia equi infection in mature horses. Nine 4-year-old Arabian geldings were experimentally infected with Babesia equi of European origin. All horses developed detectable parasitemia an average of 30 days after they were inoculated, which was accompanied by a decrease in PCV. The infections were generally mild with no animal deaths. All horses became serologically positive by the indirect fluorescent antibody test within an average of 23 days after they were inoculated and by the complement-fixation test 30 days after they were inoculated.
Antistreptolysin O titer in horses. Antistreptolysin O (ASO) titers were determined in the sera of 532 horses from stud farms and 436 working horses from small farms. A statistically significant correlation was seen between the ASO titer and the age of the horses. There was a significant difference between mean ASO titer in horses 0-2 years and horses 2-10 years In horses older than 10 years the titer was significantly higher than mean ASO titer for the group. Twenty four of 30 horses in which ASO titer was higher or equal to 80 I.U. had histories which suggested that streptococcal infection had occurred. Clinical and bacteriolo...
Studies on the sequence of variable antigen types in ponies infected with a clone of Trypanosoma evansi. The sequential appearance of variable antigen types (VATs) of a clone of Trypanosoma evansi was studied in four ponies. Using luminol-dependent chemiluminescence, VAT populations which had been isolated from parasitemic peaks of single ponies, were tested for specificity with serum samples collected from other ponies. When antibody activity was demonstrated in a combination of trypanosomes and serum, it was concluded that a major VAT appeared in common. In the serum of all animals antibody activity was demonstrated to all VAT populations isolated from the other ponies during the first 4 weeks ...
Antibodies to Borrelia burgdorferi in New England horses: serologic survey. Twelve of 50 randomly selected horses from areas endemic for Borrelia burgdorferi had indirect fluorescent antibody titers of 1:8 to 1:2,048 against B burgdorferi. One of 50 horses from nonendemic areas had a titer of 1:8. This difference in the number of horses seropositive for B burgdorferi (P less than 0.002) and our finding that seropositive horses did not have agglutinating antibodies against potentially cross-reacting Leptospira spp indicated that horses in endemic areas were exposed to B burgdorferi and that the spirochete induced an antibody response in the horses.
The use of a single complement fixation test technique in bovine brucellosis, Johne’s disease, dourine, equine piroplasmosis and Q fever serology. The same techniques may be used in the complement fixation test (CFT) for the serological diagnosis of bovine brucellosis, Johne's disease (paratuberculosis), dourine, equine piroplasmosis and Q fever (caused by Coxiella burnetii). The reproducibility of results is excellent, falling for the most part within the twofold range and never exceeding the fourfold range. Agreement with other laboratories is excellent (i.e. within twofold) in the case of brucellosis and equine piroplasmosis antibody titres. A good correlation between the occurrence of the disease and serological reactions is found on...
Serologic response and lesions in goats experimentally infected with Corynebacterium pseudotuberculosis of caprine and equine origins. Fifteen goat kids were experimentally inoculated with Corynebacterium pseudotuberculosis. Five were given a strain of caprine origin (nitrate-negative biotype) intradermally, 5 were given a strain of equine origin (nitrate-positive biotype) intradermally, and 5 were inoculated intranasally with the caprine-origin strain. Animals were monitored for 127 days. The goats given the inocula intradermally developed abscesses; those given caprine-origin strain had multiple lesions both peripherally and in visceral locations (primarily endothoracic abscesses), whereas those given the equine-origin stra...
Studies on the immunogenicity of Streptococcus equi vaccines in foals. The ability of either formalin-treated or heat-inactivated whole Streptococcus equi cell vaccines or partially purified M-protein of S. equi to give rise to protective antibody levels was studied in Standardbred foals by serological means. Two commercial preparations, i.e. a beta-propiolactone killed whole S. equi cell bacterin and a cell-free extract of S. equi cells were included in the study. The mean passive hemagglutination antibody titers (10 X log2) in sera of foals given either four doses of formalin-treated whole cell vaccine or an initial dose of formalin-treated followed by three do...
Serum antibodies to Leptospira bratislava in Swedish pigs and horses. Sera from 116 and 89 Swedish pigs and horses respectively were examined for the presence of antibodies to L. bratislava. Antibodies were found in 18.1 and 49.4% respectively of pigs and horses examined. Presence of serum antibodies was not associated with clinical signs of infection.
Experimental reactivation of equid herpesvirus 1 (EHV 1) following the administration of corticosteroids. Eight ponies were experimentally infected with equid herpesvirus 1 (EHV 1) (subtype 1). All animals showed clinical and serological evidence of infection and virus was isolated from nasal swabs and leucocytes. These ponies were kept in isolation for a further three months during which time complement fixing antibody decreased at least four-fold. Following immunosuppression with dexamethasone and prednisolone subtype 1 virus was recovered from six of the eight animals within 14 days. Five of these six ponies were viraemic and three of them shed virus in nasal secretions; only four displayed sig...
Equine lymphocyte antigens in four major Belgian horse populations. Contribution to serology and antigen distribution. 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...
Equine infectious anemia virus: immunopathogenesis and persistence. Equine infectious anemia (EIA) is a chronic, relapsing infectious disease of horses caused by a nononcogenic retrovirus. Virus persists in infected animals for life and can be reliably detected by serologic tests that measure levels of antibody to the major structural protein of the virus. Periodic virus replication in macrophages leads to an immunologically mediated acute disease characterized primarily by severe anemia. Recrudescence of acute EIA is the result of antigenic variation of the surface glycoprotein of EIA virus. The frequency and severity of clinical episodes of EIA decrease in m...
Specificity of pseudorabies virus serotests. 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.
Serologic evidence of Legionella infection in horses. The indirect fluorescent antibody test was used to examine 109 samples of equine sera randomly selected from serum pools. Results were compared with titers obtained by the microagglutination (MA) test. A high correlation (r = 0.89) was found between titers measured by the 2 tests. Blood samples were obtained serially from a total of 156 horses at a research farm and the sera were tested against Legionella pneumophila serogroups 1 through 4 using the MA test; 29 horses (19%) seroconverted to at least 1 serogroup of L pneumophila. The indirect fluorescent antibody test substantiated the results ...
Trials of an inactivated equid herpesvirus 1 vaccine: challenge with a subtype 2 virus. Serological responses following two and three doses of an inactivated equid herpesvirus 1 ( EHV -1) vaccine containing a subtype 1 strain were examined in yearling ponies. Complement fixing antibody responses were significantly higher against the subtype 1 vaccine strain than against a subtype 2 virus. Complement fixing antibody responses declined rapidly after the second dose of vaccine and had returned to almost pre-vaccination levels eight weeks after the second dose of vaccine. Complement fixing antibody titres to the heterologous subtype 2 strain increased after each successive dose of va...
Carriers of equine infectious anemia virus. Presently available data continue to support the idea that once a horse is infected with equine infectious anemia virus it remains infected indefinitely. Infection may not always be demonstrated by inoculation of plasma, serum, or whole blood transfusions into susceptible recipients, but transfusions of fresh whole blood will be infective in at least 95% of the horses testing positive in the agar gel immunodiffusion test. For detection of infectivity in a small percentage of inapparent carriers, it appears necessary to inoculate washed leukocytes collected over a period of time.
Experimental production of neonatal isoerythrolysis in the foal. Serological evidence with or without clinical signs of neonatal isoerythrolysis was experimentally produced in 6 of 8 foals born to mares allo-immunized with washed erythrocytes from the stallion. Blood group antigens were determined in all mares, stallions and foals, and the incompatible antigenic factor(s) responsible for the disease were defined. In 5 of 8 foals born to alloimmunized mares, a single antigenic factor difference accounted for the erythrocyte incompatibility between mare and foal. The erythrocyte antigen suspected as the most responsible for isoerythrolysis observed was A1. Ag...
A collaborative assay of mycoplasma reference antisera. A total of 29 Mycoplasma and Acholeplasma antiserum reagents produced in mules and horses by the Baltimore Biological Laboratory and by Huntingdon Research Centre, under the auspices of National Institutes of Health, Bethesda, USA, were tested for potency and specificity, by a great variety of serological techniques, at the FAO/WHO Collaborating centre for Animal Mycoplasmas, University of Aarhus, Denmark. Subsequently, the antisera were subjected to a collaborative assay in which 20 workers from 15 different laboratories participated under the auspices of the International Research Programme ...
