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.
Al-Khalidi NW, Weisbrode SE, Dubey JP.Nine ponies were fed 100,000 infective Toxoplasma gondii oocysts and were given corticosteroid injections before and after feeding the T gondii oocysts. Titers to the Sabin-Feldman dye tests (1:2 to 1:16,384) developed within postinoculation days (PID) 7 to 21 and antibodies persisted to PID 133. Toxoplasma organisms were isolated from the tissues of 4 ponies (heart of 4, brain of 2, spinal cord of 3, diaphragm of 1, skeletal muscle of 1, liver of 1, kidneys of 1) killed between PID 36 and 63, but not from 5 ponies killed between PID 117 and 150. Seemingly, ponies are one of the more resistant...
Kamada M, Ando Y, Fukunaga Y, Kumanomido T, Imagawa H, Wada R, Akiyama Y.A primary enzootic of equine Getah virus infection involving 722 of 1,903 racehorses occurred at a training center in Japan between September and November of 1978. Sixty-two viral agents were isolated from the plasma of 209 sick horses which exhibited pyrexia with rectal temperatures ranging from 38.5--40 degrees C, urticarial rash on various portions of the body, and edema of the hind legs. The viruses were antigenically related to the AMM 2021, Haruna, and Sagiyama strains of Getah virus. Infection and disease were produced experimentally in horses when inoculated by the intramuscular or int...
Kono Y, Sentsui H, Ito Y.A virus (Sakai) which had been recovered from an outbreak of disease in horses was found to be a small spherical enveloped RNA virus with a diameter of approximately 70 nm and a buoyant density of 1.22 g per ml. It grew well and produced a cytopathic effect in a variety of cell cultures; it was sensitive to organic solvents, heat and low pH. It agglutinated goose erythrocytes in a 0.35 M sodium chloride solution at an optimum pH of 6.2 and was antigenically identical or closely related to Getah virus, a member of the alphavirus subgroup of the Togaviridae.
Sahu SP, Dardiri AH.Uterine, cervical, and clitoral specimens on swabs from pony mares infected with contagious equine equine metritis (CEM) bacteria were streaked on agar plates. Colonies of CEM bacteria were observed under CO2 incubation in 2 days on Eugon chocolate agar and Eugon blood agar plates. The diameter of the colonies varied from 0.2 mm to 1 mm in 2 days which increased to 0.3 mm to 2.0 mm on day 4. The colonies on Eugon chocolate agar plates on days 2 to 4 were shiny, brown, round, and convex, and easily glided when pushed with a loop. The diameter of the colonies on chocolate and blood agar plates m...
Sentsui H, Kono Y.During the autumn of 1978 a disease characterised by fever and occasionally by exanthema and/or oedema of the limbs was seen in approximately 13 per cent of horses in a training stable in the Kanto district of Japan. A virus was isolated by the intracerebral inoculation of one-day-old mice from blood and nasal swabs taken from naturally and experimentally infected horses. The virus was subsequently passaged in two monkey kidney cell lines in which it produced complete cytopathic changes. Infected horses developed neutralising, complement fixing and haemagglutinin inhibiting antibodies to the v...
van der Gaag I, Tibboel D.Intestinal atresia was found in 29 animals and stenosis in five. Atresia was found in the duodenum in one pup; in the jejunum in nine calves, two lambs and one piglet; in the ileum in one pup, one lamb and one piglet; and in the colon in one foal, seven calves, one lamb, one piglet and three kittens. Stenosis was found in the duodenum of a foal, in the jejunum in two calves and one pup, and in both the ileum and the colon of a kitten. One lamb showed ileal atresia as well as ileal stenosis. We classified the atresia as type 1, membrane atresia (four cases); type 2, cord atresia (six cases); an...
Simpson CF, Taylor WJ, Kitchen H.Four splenectomized Welsh ponies were infected with Babesia equi. Two ponies were treated with imidocarb dipropionate, and two were not treated. By light microscopic examination, 1% to 2% of the parasitized erythrocytes of treated ponies contained crystalline inclusions. The crystals were rectangular, diamond, or burr shaped. They occupied most of the erythrocytic cytoplasm, and, as a result, the remainder of the pale staining cytoplasm was inconspicuous in Wright-Giemsa-stained blood smears. The size and shape of intraerythrocytic inclusions varied when examined by electron microscopy, but in...
Akinboade OA, Awani O, Best O, Cole T.Summary Twelve (12) heavy horses of the Shire breed imported into Nigeria in 1974 died within two months after importation. This was because of inclement weather and non-availability of AHS vaccine.
Justines G, Sucre H, Alvarez O.Transplacental passage of Venezuelan equine encephalitis virus, epizootic strain P-676, occurred in four of nine fetuses studied. The mares were infected near term. Virus was recovered in high titer from fetal blood and organs, while no virus was detected in maternal blood but neutralizing antibodies were present. No evidence of in utero infection was found in two fetuses from mares infected with MF-8, another epizootic strain of Venezuelan equine encephalitis virus.
Chhabra MB, Gautam OP.The prevalence of antibodies to Toxoplasma gondii was investigated among equids in 3 localities of north India, using the direct haemagglutination test. Of the 603 animals sampled, titres ranging from 1:8 to 1:512 were found in 71 (11.8 per cent). Specific titres of 1:64 or more were found in 34 (5.6 per cent) sera. The number of positive titres at Babugarh (Uttar Pradesh) was considerably higher than at 2 other localities. Although the likelihood of positive sera appeared to increased with age, the animal's sex appeared to have little influence. Subjects with reproductive disorders or eye ail...
Sturm RT, Lang GH, Mitchell WR.The sera of 2596 thoroughbred and standardbred racehorses from Ontario were examined by hemagglutination-inhibition for antibodies to reovirus types 1, 2 and 3. The prevalence of antibodies differed between the standardbred and thoroughbred horses and varied with the age groups within the two populations. While reovirus 1 was the principal virus type infecting thoroughbreds, all three types seemed to infect standardbred horses. Differences of these findings with data from similar studies in Europe are mentioned and the epizootiological and pathological significance of these findings are discus...
Akinboade OA, Awani O, Best O, Cole T.Summary Twelve (12) heavy horses of the Shire breed imported into Nigeria in 1974 died within two months after importation. This was because of inclement weather and non-availability of AHS vaccine.
Arko RJ, Wong KH.An infection model in laboratory mice for studying the bacterium (proposed name Haemophilus equigenitalis) causing contagious equine metritis is described. Small porous chambers were implanted subcutaneously into mice and after 1 to 3 weeks were inoculated with H equigenitalis. Infections that persisted for > 30 days were established by direct transfer of infective chamber fluid or by injection of laboratory-grown cultures. Immunization of mice with formaldehyde-treated cells induced significant, strain-related immunity to infection and did not appear to require complement as a protection medi...
Prescott JF, Johnson JA, Markham RJ.Four month-old foals were infected orally with 75 mL of a suspension of 5.0 x 10(8)Corynebacterium equi per mL. Two foals were killed after ten days and had scanty number of C. equi in the caeco-colic lymph nodes. No C. equi were recovered from the other two foals, killed 20 days after infection. No gross pathological change was detected in these four foals, although mild microscopic lesions were seen in the ileum of one foal. Results of lymphocyte blastogenesis using peripheral blood lymphocytes and C. equi antigens showed, however, that lymphocytes became sensitized to C. equi following this...
Platt H, Singh H, Whitwell KE.A description is given of the pathological changes present in 8 mares which died or were euthanased in the course of an outbreak of paralysis on a Thoroughbred studfarm. In all cases the principal changes were in the central nervous system (CNS) and consisted of a severe and widespread vaculitis in the brain, cord, sheaths of nerves, capsules of ganglia and occasionally elsewhere in the body. Associated with the damage to vessel walls there was haemorrhage and exudation of plasma into the perivascular tissues. Involvement of neurones was minimal and no neuronophagia was present. Six cases had ...
Tinling SP, Cardinet GH, Blythe LL, Cohen M, Vonderfecht SL.The structure of sarcocysts in a horse is presented. Light microscopic examination revealed that the maximum cyst dimensions were 136 X 990 micrometers and the cyst walls were striated and 1 to 3 micrometers thick. Electron microscopic examination revealed that the "cyst wall" was formed by villuslike protrusions of the parasitophorous vacuole's primary wall. A unique feature was the presence and arrangement of microtubules within the parasitophorous vacuole. Thirty-four to 55 microtubules extended from the apical tips and sides of each villus and passed through the ground matrix to form junct...
Schönberg A, Caldas EM, Sampaio MB, Costa E, Plank SJ.IN the State of Bahia (Brazil) the leptospirin produced in Germany for experimental use by the Institute for Veterinary Medicine, Federal Health Office, Berlin, was administered to humans and animals in order to diagnose leptospirosis in collaboration with this Institute. The results were compared with the microscopic agglutination reaction. The total number of test persons or animals was 268; this group included 81 human patients. 60 heads of cattle, 50 goats, 40 pigs, 25 horses, and 12 dogs. All were tested serologically and simultaneously the intracutaneous test was carried out. This test w...
McFarlane BL, Embree JE, Embil JA, Rozee KR, Weste JB, Artsob H, Spence L.A large number of North American equine samples were tested for the California group of arboviruses (CAL). Of 861 equine sera tested by hemagglutination inhibition using the snowshoe hare virus as an antigen, 106 (12.3%) were positive. Neutralization tests confirmed antibodies to this virus in 72 of the positive sera. This study provides evidence of CAL activity in the domestic animal population of Nova Scotia.
McGowan JJ, Allen GP, Barnett JM, Gentry GA.Infection of horse KyED cells with equine herpesvirus type 3 (EHV-3) resulted in a sevenfold increase in cytosol deoxythymidine kinase (dTK) activity. The EHV-3 dTK was purified from KyED cytosol dTK by affinity chromatography on deoxythymidine-Sepharose and characterized with respect to its electrophoretic mobility, molecular weight, substrate specificity, phosphate donor specificity, and immunological specificity. The purified EHV-3 dTK migrated in polyacrylamide gels with an Rf of 0.30 and sedimented in glycerol gradients with an S value of 5.13, corresponding to a molecular weight of 83,00...
Daugschies A.Drug resistance of parasites is a worldwide problem of increasing importance in animal production. Considerable information is available on the development of resistance in chicken coccidia and in strongyles of horses, sheep, goats and pigs. A review is given of the development, incidence, and management of drug resistance with emphasis on the situation in Germany.