Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Heydrick FP, Comer JF, Wachter RF.Phospholipid analyses of Venezuelan equine encephalitis virus showed that virus propagated in L-cell monolayers had a higher sphingomyelin content and a lower phosphatidylcholine content than virus grown in chick fibroblast monolayers. Virus of L-cell origin also was found to possess greater thermal stability than virus derived from the chick fibroblast cell.
Gruber J.Purified and concentrated Venezuelan equine encephalitis (VEE) virus derived from tissue cultures, rendered noninfectious by ionizing radiation with retention of in vitro serological activity, also retained a high level of immunogenicity. In mice, fluid vaccines afforded excellent protection against lethal challenge with homologous Trinidad strain VEE virus. A direct relationship was observed between concentration of vaccine or number of injections and survival. One intraperitoneal inoculation of undiluted vaccine protected essentially all mice challenged 21 days later with 100,000 mouse intra...
Henderson BE, Chappell WA, Johnston JG, Sudia WD.Henderson, B. E., W. A. Chappell, J. G. Johnston, Jr. and W. D. Sudia (CDC, Atlanta, Ga. 30333). Experimental Infection of horses with three strains of Venezuelan equine encephalomyelitis virus. I. Clinical and virological studies. Amer J Epidem 93: 194–205, 1971.—Clinical effect, viremias and antibody responses were compared in horses inoculated with the following strains of Venezuelan equine encephalomyelitis (VEE) virus: Fe3-7C, isolated from Culex (Melano-conion) spp. mosquitoes collected In 1963 in the Florida Everglades; TC-83, the Fort Detrick live, attenuated vaccine strain; and GJ...
Nakajima H, Ushimi C.Antigenicity of purified equine infectious anemia (EIA) virus was examined by immunodiffusion against sera obtained from horses experimentally infected with EIA virus. The purified virus reacted with the infected horse serum, and virus-specific precipitating antibody was demonstrated. Furthermore, it was found that purified EIA virus reacted against the serum of horses infected with all strains of EIA virus which were antigenically different from one another. From the result, group-specific components of the virus rather than strain-specific ones were considered to be involved in the reaction....
Pocurull DW, Gaines SA, Mercer HD.Salmonella cultures were obtained from outbreaks of animal disease from 37 states and 1 territory. They were screened for resistance to 11 antimicrobial drugs. Of the 1,251 strains studied, 935 were resistant to one or more of these agents. The three most common resistance patterns were ampicillin, dihydrostreptomycin, sulfamethoxypyridazine, tetracycline; ampicillin, dihydrostreptomycin, sulfamethoxypyridazine; dihydrostreptomycin, sulfamethoxypyridazine, tetracycline. Resistance transfer was demonstrated on 267 multiply resistant cultures, of which 181 were able to transfer all or part of th...
Nation PN.Over sixteen years, 49 horses were diagnosed by Alberta Agriculture Animal Health laboratories as having "alsike clover poisoning". There was a distinct northwestern distribution of cases, the majority coming from the Peace River district. This distribution is opposite to that of the Alberta horse population, but coincides with areas of alsike clover cultivation. Cases could be divided into chronic or nervous clinical presentations, as described by Schofield. Tissues from 45 animals were retrieved and examined microscopically. Significant histological lesions were confined to the liver and con...
Kinoshita Y, Niwa H, Uchida-Fujii E, Nukada T.Here, we describe the complete genome assembly of subsp. strain JP-H-1, collected from an equine abortion case in Japan. JP-H-1 has a 5,491,452-bp circular chromosome and 3 plasmids.
van Gorkom LP, van Wessum R, van den Hoven R.A major part of the residing horses and ponies of a riding school in Noord-Holland became affected by a febrile disorder that included anorexia, depression, conjunctivitis, urticaria, edema of the legs and laborious locomotion. All remaining horses fell ill within one week. Based on the clinical symptoms the disorder was diagnosed as vasculitis. With serology the causative agent of the disorder appeared to be equine arteritis virus.
Heitmann J, Kirchhoff H, Chercheletzi C, Jonas E, Deegen E.Acholeplasmas were detected in five of 96 feces samples from clinically normal horses. Three of the five strains isolated were identified as A. equifetale, one as A. hippikon, and one was serologically identical with the Acholeplasma strain 881.
Miyamoto C, Takashima I, Karaiwa H, Sugiura T, Kamada M, Hashimoto N.To investigate the overall prevalence of chlamydial infections in light (i.e. non-draught) horses in Japan, 599 sera obtained from 12 localities in 1991 were tested for complement fixation antibodies. The mean antibody positive rates of the all sera were 15.2% (91/599) and the regional positive rates were higher in Honshu (19.1%, 48/251) and Kyushu (20.0%, 20/100) than in Hokkaido (9.3%, 23/248). In Honshu, the highest rate (56.0%, 28/50) was observed in Utsunomiya. Analysis of the positive rate in different age groups showed that the 2-5 years age-group had the highest prevalence of chlamydia...
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.
Alstad AD, Sahu SP, Pedersen DD, Saari DA, Kawaoka Y, Webster RG.An influenza virus, A/equine/Alaska/1/91 (H3N8), was isolated from horses from Alaska with an acute respiratory infection. Pathogenic and serologic studies revealed that this virus is similar to previously isolated equine H3N8 influenza viruses. Antigenic analyses utilizing hemagglutination inhibition and neuraminidase inhibition assays indicated an antigenic drift from the prototype equine H3N8 influenza virus, A/equine/Miami/1/63. Partial sequence analysis of the A/equine/Alaska influenza virus indicated that each of 8 gene sequences are of equine origin.
Sánchez-Pacheco UA, Bahena-Mondragón BM, Hernández-Piedras FR, Soria-Osorio R, Meneses-Acosta A.The immunotherapy agents derived from horses are biological products that allow the neutralization of clinically relevant immunogens, such as the SARS-CoV-2 virus that causes COVID-19, or the neutralization of toxins present in the venoms of snakes, spiders, and other poisonous animals. Due to their importance, detecting adventitious viruses in equine hyperimmune serum (raw material in industrial processes) is a critical step to support the safety of products for human use, and, in consequence, it is a requirement for commercialization and distribution. The safety of the finished product is ba...
Horner GW.To review laboratory aspects of the equine viral arteritis (EVA) control scheme in New Zealand between 1989 and 2002. Methods: The optimisation and performance of the virus neutralisation test (VNT) for equine arteritis virus (EAV) antibody, and the cell culture test to detect EAV in semen were analysed. Laboratory data and control scheme results were reviewed. Results: Using optimised tests, it has been shown that antibody prevalence in Standardbred horses has steadily declined from 54% to <20%. Prevalences in Thoroughbred horses have remained at a low level of around 3%. The number of horses...
Espino-Solis GP, Osuna-Quintero J, Possani LD.This work reports the cloning and sequence determination of the horse alpha subunit of the integrin CD11c/CD18, a marker of dendritic cells. A cDNA clone of 4582 base pairs was obtained. It encodes a protein segment of 1086 amino acid residues of the extracellular domain with 10 potential sites of glycosylation, a transmembrane domain of 32 residues and a C-terminal cytoplasmic tail of 24 residues. A phylogenetic analysis of this integrin shows close similarity (83%) with that of Canis familiaris.
