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.
Gard GP, Marshall ID, Walker KH, Acland HM, Saren WG.An outbreak of Murray Valley encephalitis (MVE) occurred in New South Wales during the first five months of 1974. Specimens from 52 horses with nervous disease collected January to May 1974 were examined histopathological or virologically. Although MVE virus was not isolated, 13 horses had serological evidence of recent infection with MVE virus. Another 4 horses had evidence of recent infection with Ross River virus. Two animals had histological evidence of viral infection of the central nervous system. Attempts to experimentally infect 2 horses with a low dose of MVE virus were not successful...
Beech J, Dubielzig R, Bester R.Periodic episodes of diffuse central nervous system disease occurred in a yearling Thoroughbred gelding that had a history of frequent respiratory tract disease and stunted growth. Hepatic encephalopathy was diagnosed on the basis of history, clinical signs, prolonged bromsulphalein clearance, and increased blood ammonia content. Because of the poor prognosis and recurrent clinical signs the horse was euthanatized. Necropsy revealed an arteriovenous anomaly and thrombosis of the portal vein. Histologically, there was diffuse primary astrocytosis of the brain.
Allen GP, O'Callaghan DJ, Randall CC.Infection of cells with equine herpesvirus type 1 (EHV-1) or type 3 (EHV-3) resulted in the induction of a DNA polymerase activity distinguishable from host cell DNA polymerases by its high salt requirement for maximal activity. By column chromatography on DEAE-cellulose, DNA-cellulose, phosphocellulose, and hydroxyapatite, the EHV-1-induced polymerase was purified 500-fold with 1–2% recovery of total activity from the nuclei of infected hamster livers. The final enzyme preparation was homogeneous as judged by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Calculations based ...
Hayes CG, Wallis RC.Western equine encephalomyelitis (WEE) has been recognized as a serious public health problem in western North America for more than 30 years. WEE appears to exist endemically in numerous foci in that region, with a low incidence rate among humans. Severe outbreaks, however, have occurred periodically. For example, during 1941 a severe epidemic involving more than 3000 cases in humans occurred in North Dakota, Minnesota, and in the adjacent areas of Canada. The case fatality rate ranged from 8% to 15%. Epizootics among horses are more common. More than 600 cases of WEE were diagnosed among hor...
Wilks CR.The immune response in horses following experimental infection with equine herpesvirus type 1 (EHV-1) was assessed by measuring cytotoxicity for EHV-1-infected target cells. A technique was developed, using [125I]5-iodo-2'-deoxyuridine ([125I]IUDR)-labeled equine fetal kidney cells infected with EHV-1 as the target cells. It was shown that peripheral blood leukocytes from a recovered horse were capable of lysing target cells, as measured by the loss of radio-active label. Following the experimental infection of specific-pathogen-free ponies with EHV-1, cytotoxicity was obtained with fresh auto...
Takizawa T, Ito T.Supposing two mathematical models, additive and multiplicative, the authors estimated the secular trends of annual morbidities (1949 approximately 1975) of twelve infectious diseases of domestic animals. For each diseases ten different trend curves were fitted. It was found that five regression equations, namely, those for bovine trichomoniasis, bovine tuberculosis, equine infectious anemia, pullorum disease in chickens, and foulbrood, gave the coefficient of determination of 97.9, 92.7, 91.0, 93.5, and 85.2%, respectively. Four of them were multiplicative, and the remaining one for equine inf...
Weiland F, Matheka HD, Coggins L, Hatner D.Morphological studies of EIAV reveal knobs on the surface of the particles, conically and tubularly shaped cores, budding particles with dense crescents directly underlying the plasma membrane, and distinct intracytoplasmic structures in infected cells.
Akkmeteli MA.Although mycotoxicoses attract more and more attention, the epidemiology of these diseases is still not adequately studied. The author devotes his study to certain diseases. In addition to the diseases whose mycotoxic nature is in no doubt, he conditionally includes certain diseases whose mycotoxic causation needs further proof. The author has assigned stachybotryotoxicosis and alimentary toxic aleukia or fusariotoxicosis to the first category and endemic nephropathy and primary liver-cell carcinoma to the second. His intention in adopting this approach is to establish the common features and ...
Benmansour A, Benelmouffok A, Bouguermouh A.During an epizootic of equine acute respiratory disease in Algeria, a strain of equine influenza virus was isolated. Sera examination by hemagglutinin inhibition test and complement fixation test confirmed the etiology of the disease. The first and second outbreak of the disease remained localised. The third outbreak spread within few months to all parts of the country. Horses vaccinated with a commercial equine influenza vaccine remained healthy.
Melnick JL, Schmidt NJ, Hampil B, Ho HH.This paper describes the preparation of seven combination pools of equine antisera, designated J though P, for identification of 19 coxsackievirus A immunotypes. Each pool is composed of 4 to 6 antisera; the serotypes included are A1-6, 8, 10-15, and 17-22. These pools, unlike the previously prepared A-H enterovirus pools, were lyophilized from volumes of 0.5 ml dispensed into 5-ml vials, and when rehydrated with 5 ml of diluent provide 50-antibody-unit material ready for use in identification tests without further dilution. Procedures for using the antiserum pools are given, and guidance is p...
Smyth JD.The genetics of speciation in the genus Echinococcus are briefly discussed. As the organism is a hermaphrodite and multiplies asexually in the larval stage, the genetic mechanism for the ready production of new strains is inherent in the life-cycle. Some biological, biochemical and nutritional differences between the horse and sheep strains are examined. The sheep strain may be grown to sexual maturity, in vitro, in a diphasic system; the horse strain fails to grow in such a system. Differences have also been demonstrated between the soluble proteins of the two strains. The sheep strain is inf...
Thouless ME, Bryden AS, Flewett TH, Woode GN, Bridger JC, Snodgrass DR, Herring JA.Human, piglet, mouse, foal, lamb, calf and rabbit rotaviruses all infected, but could not readily be subcultured in LLC MK2 cells. Cells infected with mouse and calf rotaviruses reacted by indirect immunofluorescence (FA) with convalescent serum from children, piglets, mice, foals, lambs, calves or rabbits, taken after rotavirus infection. Human, calf, piglet, mouse and foal rotaviruses reacted with human, calf, mouse, foal and lamb convalescent serum by complement fixation (CF). It was not possible to distinguish between different rotaviruses by CF or FA. Neutralization tests, however, detect...
Barrowman PR.To establish the ability of Trypanosoma equiperdum to cross the blood-brain-barrier in the horse, a susceptible stallion was infected via the cerebrospinal fluid of the subarachnoid space by lumbosacral puncture. Cerebrospinal fluid with low detectable levels of trypanosomes removed from a dourine-infected mare by lumbosacral puncture was used for infecting the animal. The parasite was detected in blood smears of the recipient 13 days after infection and the subsequent parasitaemia and clinical course of the disease followed that of naturally infected horses.
Murray MD, Snowdon WA.The distributions of the following feral animals are given -- cattle, buffalo, pig, goat, deer, camel, horse, donkey, fox, dog and cat -- and the native dingo. The possible role these and the native rodents, marsupials and monotremes would play should an exotic disease of livestock enter Australia is discussed. It is considered that feral animals would be important in creating foci from which the disease would spread.
Verberne LR, Mirck MH.A comparative study of the literature of the past ten years showed that vaccination of horses and ponies against influenza is best done using adjuvant-containing vaccines. Comparable results may probably be obtained by twice inoculating an aquenous vaccine. There are no drawbacks to the use of aluminium-hydroxide as an adjuvant when mineral oil is used as an adjuvant, the first and second vaccinations do not present any problems.
Rastegaev IuM.Alongside with a high intensity of infection of horses with botfly larvae there was observed mass aberrant parasitism of horse botflies in farms of Astrakhan, Guryev and Uralsk Provinces, and in the Kalmyk ASSR in 1980-1981 and 1987. As a result of extremely high aggregation of horse botfly larvae in their usual localization places, Gasterophilus pecorum larvae remained, due to interspecific competition, in nonspecific places (oral cavity, pharynx), adapted to new habitats and normally developed. Their number varied from 260 to 750 specimens. Localization of G. pecorum larvae in the mentioned ...
Campbell TM, Studdert MJ.An inactivated equine adenovirus type 1 (EAdV1) vaccine was administered to 4 horses. The horses had virus-neutralizing (VN) antibody titers before they were vaccinated, but developed higher VN antibody titers in response to vaccination. Nonvaccinated control horses did not show increases in VN antibody during the study, indicating that any increase in antibody titer in vaccinated horses was a result of vaccination and not due to an EAdV1 epizootic during the study. Specific EAdV1 in vitro lymphocyte blastogenesis (LB) was evaluated, using lymphocytes from 4 vaccinated and 2 control horses. Ho...
Koekemoer JJ, Paweska JT, Pretorius PJ, van Dijk AA.We present the first VP2-gene phylogenetic analysis of African horsesickness (AHS) viruses within a serotype. Thirteen AHSV 7 isolates were obtained from cases that occurred in South Africa during 1998-1999, and three were historical AHSV 7 isolates. The goals were to start a database of isolates of known location and time of isolation and to determine if we could identify the origin of an AHS outbreak in the surveillance area in the Western Cape. We prepared full-length cDNA copies of the VP2-genes of the isolates. Nucleic acid sequence data of a 786 bp region was used to characterize the gen...
Boswinkel M, van der Lugt JJ, Sloet van Oldruitenborgh-Oosterbaan MM.Rhodococcus equi infection occurs worldwide and is especially a problem in foals, where it often causes colitis or pneumonia. Other organs are seldom affected, and their involvement is regarded as a complication of pneumonia and/or colitis. Vertebral osteomyelitis is one such rare complication and is probably caused by haematogenous spread from inflammatory lesions in the lungs and/or intestine. In rare cases, osteomyelitis can be caused by contamination of a wound. This case study describes a foal with vertebral osteomyelitis due to R. equi in which there were only minor inflammatory changes ...
Oki Y, Miura K.In the recent years, various red cell auto-antibodies have been determined in someanimal diseases, including autoimmune hemolytic anemia and systemic lupus erythe-matosus in dogs, ") Aleutian disease in minks, 8) and equine infectious anemia."?">In this report, the red cell auto-antibodies were examined for symptomatiCchanges, serological characteristics, and immunopathological roles in 20 horses infectedwith equine infectious anemia virus (Table l).Pathologic cold hemagglutiuain and warm hemagglutinin were identified in theplasma of artificially infected horses. The direct antiglobulin tests ...