Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Goto H, Shimizu K.The first outbreak of equine influenza (EI) infection in Japan was recognized during the period December 1971 to January 1972 [1, 6]. No evidence of the disease had been found before then [2,6]. The etiological agent of this epizootic was identified by hemagglutination-inhibition (HI) and neutralization tests with chicken or ferret antiserum as the subtype 2 of EI virus (6, 7). However, the isolate, A/equine/Tokyo/71 (Tokyo) strain, was not completely identical to the prototypic A/equine/Miami /63 (Miami) strain of the subtype 2, since antibody responses of convalescent horses were 2 to 16 tim...
McQueary CA, Worley DE, Catlin JE.Of 22 foals from 4 localities in southwestern Montana, 59% were found to be infected with Eimeria leuckarti. Oocysts collected from feces of 4 positive horses were sporulated and subsequently administered to a 5- to 6-month-old foal. The prepatent period was 31 days and the patent period was between 5 and 10 days.
Grelck H, Hörchner F, Wöhrl H.Ten pony foals were infected with Fasciola hepatica; five animals received up to 1000 metacercariae orally, the remaining animals received up to 80 specimens of 24 hours old adulescariae intraperitoneally. The rate of development of the parasites varied in a wide range between 0,2 and 41%. Most of the liverflukes were found in animals severely infected with strongyles in the same time. Only 22 weeks after oral infection, the flukes had reached a length of 20 mm and sexual maturity. Fasciola-eggs could not be detected in the feces.
Gerber JD, Marron AE, Bass EP, Beckenhauer WH.The cell-mediated immune response and antibody response of horses of varying ages and of pregnant horses to equine herpesvirus 1 antigen were examined. Six to eight month old horses showed either no increase or slight increases in anti-equine herpesvirus 1 serum neutralizing antibody following vaccination and revaccination with a modified live equine herpesvirus 1 vaccine. However, these same horses showed a marked increase in the cell-mediated immune response to equine herpesvirus 1 as measured by the lymphocyte transformation test. Eighteen to 21 month old horses showed four to 64-fold incre...
Dutta SK, Campbell DL.Blastic transformation of peripheral blood mononuclear cells and serum neutralization antibody levels for equine herpesivurs type 1 were measured in 19 mares from three farms at the time of termination of their pregnancy by normal foaling or viral abortion. The stimulation indexes of lymphocytes obtained from the mares from two farms (Farm 1 and 2) which had virus abortions, ranged from 2.1 to 10.8. But there was no significant difference in stimulation index levels between the aborting and normal foaling mares on these two farms. Equine herpesvirus type 1 was isolated from the mononuclear cel...
Greatorex JC.The clinical manifestations, diagnosis and differential diagnosis of "verminous aneurysm" formation at the root of the cranial mesenteric artery and coeliac artery resulting from Strongylus vulgaris larvae migration are described. Forty-nine of 57 cases were successfully treated with low molecular weight dextran (dextran 70).
Mirck MH.Patent S. westeri infection is particularly common in unweaned foals (61.2 per cent). It is much less common in foals which have been weaned (15.4 per cent). Examination of the faeces of ten artificially reared foals (free from worms) did not supply any evidence of possible prenatal (intra-uterine) helminth infection. In one Shetland pony mare, larvae of S. westeri were found to be present in the milk on the tenth, twenty-fourth and thirty-second day after parturition. Larvae were not detected in the milk of the other mares but all foals showed patent S. westeri infection within from thirteen ...
Rumbaugh GE.Physical, neurologic, and clinicopathologic findings in a 3-year-old female Morgan horse with anorexia and nasal discharge suggested suppurative meningitis. Necropsy findings substantiated the tentative diagnosis. Actinomyces sp was cultured from a meningeal abscess surrounding the pituitary gland and from resolving lung abscesses.
Taylor HW, Vandevelde M, Firth EC.A horse that suddenly became recumbent had a focal ischemic infarct of the spinal cord between C6 and C7. The infarct was attributed to multiple fibrocartilaginous emboli. Adherence of fibrocartilaginous debris to the outer surface of the dura was interpreted as evidence that intervertebral disc degeneration and displacement of the nucleus pulposus had occurred and that the emboli arose from the disc.
Buening GM, Perryman LE, McGuire TC.Serum concentrations of immunoglobulin M (IgM) and immunoglobulin G (IgG) can be determined in the horse with a satisfactory degree of accuracy, using commercially available reagents. Selected lots of anti-human IgM can be used in precipitation tests to detect and quantitate equine IgM. Commercially available anti-equine IgG tended to overestimate the amount of IgG in single radial immunodiffusion tests. Even with these limitations, commercial reagents can be used to differentiate immunodeficiency disorders of foals, including combined immunodeficiency and failure of passive transfer of colost...
O'Sullivan BM, Goodwin JA.On 6 properties in south-western Queensland an outbreak of nervous disease occurred horses due to ingestion of Swainsonia (Darling pea). Loss of condition, depression, hyperaesthesia and hyperexcitability were seen in affected horses. At autopsy of 2 horses generalised c ytoplasmic vacuolation was seen in the neurones of the central nervous system and in the liver, adrenal and thyroid. The clinical and pathological features were similar to those described in horses suffering from Swainsona poisoning in Australia and Astragalus and Oxytropis in North America.
Verma BB, Biberstein EL, Meyer ME.A serologic survey was made of the prevalence of common leptospiral infections in horses in California. A total of 465 serums were tested, using the microscopic agglutination method, against 5 leptospiral serotypes: Leptospira pomona, Leptospira icterohaemorrhagiae, Leptospira canicola, Leptospira grippotyphosa, and Leptospira hardjo. Of the serums tested, 127 (27.30%) were positive against 1 or more of the leptospires, with percentage distribution among the reactors as follows: L pomona, 12.47%; L icterohaemorrhagiae, 10.32%; L canicola, 3.22%; L grippotyphosa, 0.86%; and L hardjo, 0.43%. The...
Hallauer C.1. Equine infectious anemia (EIA) is an immunologically-medicated disease. Immune complexes formed in blood and tissues are responsible for most symptoms and lesions (anemia, splenomegaly, lymphadenopathy, glomerulonephritis, etc.). In addition, a state of cellular hypersensitivity of the delayed type is involved in the pathogenesis. 2. Periodical attacks of pyrexia and clinical illness in the presence of immunity are caused by antigenically-modified variants of virus. By means of immunosuppressive treatments similar relapses of fever associated with the appearance of new virus variants can be...
Dyson DA, Smith GR.When incorporated in solid medium at a concentration of 15 per cent, the defibrinated blood of certain horses strongly suppressed the growth of some, but not all, strains of Mycoplasma mycoides subsp mycoides so that many colonies failed to develop to a visible size. Blood from a single rabbit was tested and found to exert a similar effect. There was striking variation in the degree of inhibition produced by different samples of horse blood and, of five strains of the organism examined, the T1 vaccine strain was the most susceptible. The results suggested that the effect was not due to antibod...
Mirck MH.A form of strongyle infection in young horses and ponies, observed during the period from November to May, is described. Large numbers of larvae of Cyathostominae in the fourth or early fifth stage of development are found to be present in the (often watery) faeces. This excretion of larvae is not affected by treatment with anthelmintics. A large number of these patients die from the sequelae of verminous enteritis.
Gleeson LJ, Studdert MJ.Intrauterine infection of pregnant mare with equine herpesvirus type 2 (EHV 2) did not result in foetal abortion, stillbirth or recognisable disease. Collection of uterine fluid by allantocentesis or amniocentesis 107 days after inoculation confirmed that intrauterine infection was established. EHV 2 was isolated from both allantoic and amniotic fluid separately collected at the time of elective Caesarean section 156 days after inoculation and virus neutralising antibody to EHV 2 was present in the foal's presuckle serum at birth. A very mild clinical disease, characterised by a scant, mucous ...
Banerjee DP, Singh B, Gautam OP, Sarup S.An intradermal skin test, to demonstrate a delayed cutaneous hypersensitivity reaction in Babesia equi infection in donkeys, was developed. A skin reaction to B. equi antigen was elicited in vaccinnated, infected and carrier intact and splenectomised donkeys. The histopathological examination of the skin biopsy revealed infiltration of mononuclear cells and accumulation of oedematous fluid in the deeper layers of the dermis. A leucocyte migration inhibition test was developed and its specificity as an in vitro measure of cell-mediated immunity to B. equi antigen was established. The results of...
Shen DT, Crawford TB, Gorham JR, McGuire TC.Twelve chemicals and commercial disinfectants were tested for inactivation of equine infectious anemia virus. In the presence of 10% bovine serum, all chemicals inactivated 4 log10 (based on 0.1 ml) of the virus within 5 minutes at 23 C. A reduction of at least 4 log10 was observed when the virus was exposed for 1 minute to substituted phenolic disinfectants (3 commercial preparations and sodium orthophenylphenate), halogen derivatives (iodophor and sodium hypochlorite), chlorhexidine, and 70% ethanol. Sodium hydroxide (5%), 2% formalin, and 2% glutaraldehyde were slower to inactivate the viru...
Hinchcliff KW, Byrne BA.Aspects of a detailed examination of the respiratory system of the horse with suspected respiratory system disease are described. This review includes discussions of the terminology of signs associated with respiratory system disease; radiographic examination of the upper and lower airways and thorax; nuclear scintigraphy; percutaneous and endoscopic tracheal aspiration; bronchoalveolar lavage; electromyography; blood gas analysis; and pleuroscopy and pleural fluid examination.
von Zallinger C, Tempel K.A review of the latest literature concerning the present level of radiation therapy in veterinary medicine is given. In a general section physico-technical as well as biological fundamentals are discussed. In the special part of the paper indications for a radiation therapy of dogs, cats and horses are stated. In this respect the basis for a decision is the TNM-classification into different clinical stages according to the directions of the WHO. Tumors of the hemolymphatic system are very responsive to radiation therapy. While epithelial tumors are sensitive, tumors arising from the mesenchyma...
Tatarov G, Khristov S, Martinov S, Gergov P, Khristova V.Attempts were made to produce inactivated vaccines against horse Herpes virus 1, using various inactivating agents and adjuvants, Best results were obtained with vaccine No 3 (glutaraldehide inactivator and "CTC" adjuvant). Used were two strains of the virus (St. Karaja and Varna). isolated in this country in cell cultures of a sucking pig kidney. Vaccine No 3 showed good immunogenic properties. Its application resulted in the full cease of abortions and respiratory diseases on the base of infection with the horse Herpes virus 1. The vaccination protects newborn colts from rhinopneumonitis if ...
Duncan JL, McBeath DG, Best JM, Preston NK.The efficacy of fenbendazole against immature stages of Trichonema spp., Strongylus vulgaris and Strongylus edentatus was evaluated. Naturally infected 6 to 12 month old ponies were given single, oral doses of 0, 15, 30 and 60 mg/kg of body weight. A dose response relationship was noted between increasing dose levels and efficiency against larval trichonemes and migrating stages of S. vulgaris and S. edentatus. Dose levels of 30 mg/kg and higher removed 93 per cent of mucosal stages of Trichonema spp., while doses of 60 mg/kg removed 83 per cent and 89 per cent of the migrating larvae of S. vu...
Ullrich E, Selbitz HJ, Schieck R, Friedrich U, Schulz J.Clinical, bacteriological and serological examinations on a 6 years old pony mare were performed. Cytological alterations in the genital tract were also recorded. A cellular reaction was seen after infection with T. equigenitalis. This reaction is an evidence for infection but it is not specific for this organism. Cytological studies should be performed on mares especially in cases of latent infections to complete bacteriological examination and to prevent false positive or negative results.