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.
Smith KM, Barber SM.A two year old Thoroughbred gelding, presented with guttural pouch hemorrhage, had the internal and external carotid arteries ligated. Guttural pouch mycosis was detected on endoscopic examination. After one month of topical antifungal therapy, the horse was returned and euthanized because of recurrent epistaxis. A bacterial infection of the guttural pouch with associated ulceration and hemorrhage from the maxillary artery was found at necropsy.A two year old grade gelding had ulceration and hemorrhage from the external carotid artery. Utilizing balloon-tipped catheters and arterial ligation, ...
The Journal of hygieneJune 1, 1984
Volume 92, Issue 3 365-375 doi: 10.1017/s0022172400064585
Gray SJ.Faecal samples from 110 horses, 115 pigs, 111 sheep and 123 cows were examined for the presence of Aeromonas hydrophila, which was also sought in the available drinking water. The overall faecal rate was 11.8%, but significantly more bovine than other samples were found to be positive. There was significant association between the isolation of A. hydrophila from all animal faeces and its presence in drinking water, but this was not found when individual animal groups were analysed separately. An enrichment technique increased the total number of isolates by 77.1%. Strains of differing origins ...
Strzemienski PJ, Benson CE, Acland HM, Kenney RM.Two groups of 3 mares were inoculated with Haemophilus equigenitalis or Pseudomonas aeruginosa on the 1st day of estrus. Uterine flushing samples were recovered on day 3 of estrus and day 8 after ovulation for each cycle. Mares were killed 22, 25, and 30 days after inoculation with P aeruginosa and 45, 46, and 49 days after inoculation with H equigenitalis. Pseudomonas aeruginosa was recovered from the uterus of 2 mares 48 hours after inoculation. Although the initial flushing sample of 1 of these 2 mares had an increased total protein concentration, there appeared to be little difference betw...
Bertram TA, Jensen AE.Morphology and function of equine neutrophils were evaluated after combination with contagious equine metritis organism (CEMO) or 1 of 2 CEMO lipopolysaccharides (LPS). The 2 LPS (LPS-a; LPS-p) isolated from the CEMO contained 14- and 16-carbon fatty acids, ketodeoxyoctanate, hexose, and heptose, but were morphologically distinct. Neutrophils exposed to LPS had fewer granules, whereas those exposed to CEMO had more granules than did the controls (phosphate-buffered saline solution). Neutrophil iodination was significantly increased with 10 and 25 micrograms of LPS-a, but not significantly alte...
Blue HB, Blue MG, Kenney RM, Merritt TL.Forty uterine fluid samples were obtained from 4 mares classified as resistant to uterine bacterial infection. The uterus of each mare was flushed with 50 ml of saline solution during estrus and diestrus of successive estrous cycles. Bacteria or fungi were isolated from 4 samples, and 7 additional samples were obtained from a mare with active intrauterine infection. Fluid volumes obtained during estrus (means = 40.3 +/- 11 ml) tended to be greater than those recovered during diestrus (means = 36.8 +/- 7.9 ml), but the difference was not significant. Concentrations and yields of protein in reco...
Munroe GA.PYLORIC stenosis occurs commonly in man and the dog but only rarely in the horse and cat. Two reports of pyloric stenosis in the horse have been published, both of these occurring in foals of less than two months of age (Barth, Barber and Mackenzie 1980; Crowhurst, Simpson, McEnery and Greenwood 1975). Surgery on the pylorus performed under general anaesthesia was successful in both cases. This report describes a case of pyloric stenosis in a Thoroughbred yearling.
Rousseaux CG, Futcher KG, Clark EG, Naylor JM.Two cases of cauda equina neuritis are compared and contrasted. Neurological deficits of the tail and perineum were noted and functional deficits were seen in gait, urination, defecation and cranial nerve function. Lesions consisted of nonsuppurative inflammation of the nerve trunks and proliferation of the perineurium of the cauda equina. Cranial nerve involvement in one case supported a diagnosis of polyneuritis equi rather than cauda equina neuritis. The possible etiologies and pathogenesis of this disease are discussed.
Miller RI, Campbell RS.Pythiosis (204 cases, 77%), basidiobolomycosis (48 cases, 18%), and conidiobolomycosis (14 cases, 5%) were diagnosed morphologically from 266 horses with phycomycosis. All lesions were cutaneous ulcerative granulomas and three horses with pythiosis had metastatic lesions in regional lymph nodes. Lesions of pythiosis contained characteristic yellow, coral-like coagula and had a fibrotic surface containing sinus tract openings. Basidiobolomycosis was characterized by infrequent small yellow coagula and a yellow line of fungal invasion beneath an edematous surface. Lesions of conidiobolomycosis h...
DiPietro JA, Todd KS, Reuter-Dallman V.Ivermectin given IM at 200 micrograms/kg, alone or in combination with procaine penicillin G at 600 IU/kg, to 20 randomly selected young horses of various breeds reduced fecal strongyle egg counts from 400-4100 epg (avg greater than 1000) pretreatment to zero 7 days posttreatment. There were no systemic or injection-site reactions, either immediate or delayed, in any of the horses.
Krpan MK.Transtracheal aspiration is used to obtain samples for culture and cytologic examination of respiratory tract secretions and exudates. A 15-cm-long area of the ventral midcervical region is surgically prepared, a small site infiltrated SC with 2-3 ml lidocaine, and a stab incision made in the skin. A trocar with cannula is inserted through the incision and annular ligament into the trachea and the trocar removed. An 8-Fr polypropylene catheter is inserted about 35-40 cm down the trachea and attached to a 30-ml syringe, containing 20 ml sterile saline, with a 3-way stopcock . The saline is rapi...
Coignoul FL, Cheville NF.Six pregnant mares were given equine viral arteritis virus intravenously. Tissues from genital tracts, placentae, and fetuses were examined by light and electron microscopy to study the mechanism of abortion. Four mares which died with acute disease had diffuse vacuolation of endometrial epithelium and systemic necrotizing vasculitis. Two of these mares had dead fetuses and two had live fetuses; virus was isolated from tissues of one live fetus. Placentae of mares dying from acute disease did not have lesions attributable to infection; virus was isolated from two of these placentae. One of the...
Jørgensen RJ, Andersen S.Between 10 and 25% of the Dictyocaulus arnfieldi larvae excreted in faeces from a naturally infected donkey were harvested as infective stages from faecal cultures by means of Pilobolus fungi. The faeces were collected between 24 and 56 hours after drenching the donor animal with Pilobolus spores and kept at 16 +/- 2 degrees C. Most larvae were collected between the 5th and the 8th day of culturing during which period fructification and sporangium discharge also peaked. The sporangia and the adhering larvae were collected in Petri dishes inserted between the faecal mass and a light source. All...
Brook D.A guarded, sterile swab is used to obtain samples for uterine culture. With the mare in stocks, the tail bandage and the perineum washed, the culture rod is introduced into the vagina with a gloved hand. After the rod is guided through the cervix, the guard cap is dislodged and the swab is rubbed along the endometrium, after which the rod is extracted. Samples for uterine culture should only be obtained during full estrus. Swabs should be directly plated onto agar within 2 hours of collection. Blood agar is appropriate for initial screening, but use of specialized types of agar expedites ident...
Lyons ET, Drudge JH, Tolliver SC, Swerczek TW, Crowe MW.A total of 396 Thoroughbreds (86 males, 293 females, and 17 geldings) in Kentucky, 1 to 30 years of age, were examined at necropsy for presence of Anoplocephala perfoliata (2 female horses were not examined) in the cecum for lesions of Draschia megastoma in the stomach, during the 1-year period of Mar 1, 1982 through Feb 28, 1983. Prevalence of A perfoliata was 53% and of lesions of D megastoma was 63%. All lesions of D megastoma were partially or entirely in the glandular region of the stomach. Distances of the midpoint of these lesions from the margo plicatus varied from 0 to 290 mm. The cen...
Ribbeck R, Ilchmann G, Hiepe T.Research into the immunological diagnosis of gasterophilosis. So far there have been no reliable methods of diagnosing equine gasterophilosis intra vitam. Horses from the G.D.R. and the M.P.R. spontaneously infected with Gasterophilus spp. were tested for antibodies by the immunotechniques of counterimmunoelectrophoresis after Pesendorfer, passive haemagglutination and the intradermal test using antigen made from larvae of all 6 Gasterophilus spp. present in the palaearctis. All 3 techniques produced positive results. The intradermal injection produced an immediate reaction. A correlation betw...
Dik KJ.Radiographically, joint ill in foals is subdivided into four different types: Type P - osteomyelitis in the meta- and/or epiphysis adjacent to the physis. Type E - osteomyelitis in the epiphyseal subchondral bone. Type S - synovitis confined to the joint itself. Type T - osteomyelitis in the small tarsal bones. The radiographical features corresponding with the different types, the relationship between the radiological, pathological, bacterial and clinical findings, and the recommended radiographic procedure are discussed in detail.
Bouillant AM, Becker SA.The successive steps of maturation of seven retroviruses from five species of farm animals and one retrovirus from a mouse were compared in cell cultures. The viruses included three type C oncoviruses, one spumavirus, and three lentiviruses. Although members of the 3 subfamilies shared some gross morphologic features such as budding on plasma membranes, core, and surface projections, differences were noted in the ultrastructural detail of these features. Type C oncoviruses did not show any structural differentiation in identifiable form in the cytoplasm as opposed to characteristic features ob...
Caughman GB, Staczek J, O'Callaghan DJ.Enveloped virions and nucleocapsids of equine cytomegalovirus (ECMV; equine herpesvirus type 2) have been purified from the supernatants and the nuclear extracts of infected rabbit kidney (RK) cells, respectively, and their structural protein compositions have been analyzed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that ECMV nucleocapsids were composed of nine proteins (average molecular weights = 148K, 52K, 49.5K, 46K, 43.5K, 38.5K, 27K, 20K, and 18K), which together constituted 89% of the total nucleocapsid protein on the basis of incorporated 3H-labeled am...
Burrows R, Goodridge D, Denyer MS.Vaccinated yearlings , two-year-old and in-foal pony mares with appropriate controls were exposed to aerosols of a subtype 1 virus one to two months after two or three vaccinations; all became infected. No obvious differences in the febrile responses, clinical signs and subsequent abortions were found between vaccinated and control mares. All vaccinated yearlings and two-year-old ponies developed a febrile respiratory disease but this was less severe than that suffered by the controls and the amounts and duration of virus shedding were reduced.
Mumford JA, Bates J.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...
Yamagishi H, Ide S, Eiki T, Eiguchi Y, Nagamine T, Igarashi Y, Yoshioka I, Matumoto M.ESK cells, a stable cell line derived from a swine embryo kidney, were found to be a good medium for plaque formation of the Prague and Miami strains of equine influenza virus. Factors influencing the plaque formation were investigated and a plaque assay for these viruses was worked out. The method is not only simple enough for routine use, but also is as sensitive as the egg inoculation method. The method was readily adapted for a neutralization test.
Aguilar CM, Fernández E, de Fernández R, Deane LM.During an outbreak of cutaneous leishmaniasis in a locality (Las Rosas, Cojedes State, Venezuela) previously non-endemic, 12.9% of humans, 7% of dogs and 21.4% of donkeys (Equus asinus) had lesions with parasites. The agent in the three hosts was identified as Leishmania braziliensis, subspecies braziliensis at least in man and donkey. The probable vector was Lutzomyia panamensis. No infection was found in a small sample of wild mammals examined. The outbreak was apparently linked with the importation of donkeys with ulcers, from endemic areas. The authors call attention to the fact that not o...
Lindberg R.A morphological study on equine granulomatous enteritis (EGE) in 13 horses is presented. All horses were young (1 to 5 years old) standardbreds. Based on gross pathology, cases were classified into those with diffuse (11 cases) and those with localized (2 cases) small bowel lesions. The granulomatous reaction in the gut was marked by diffuse and patchy infiltrates and distinct granulomas, composed of epithelioid cells, macrophages and lymphoid cells, and was devoid of necrosis. Salient accompanying features of the small bowel included lymphoid hyperplasia, peri-lymphatic and transmural inflamm...
Drudge JH, Tolliver SC, Lyons ET.From 1977 to 1981, critical tests were conducted on 10 horses naturally infected with population B strongyles. Drugs tested were: oxibendazole (OBZ), 10 mg/kg of body weight (n = 1); albendazole, 10 mg/kg (n = 1); a mixture of thiabendazole (TBZ), 44 mg/kg and trichlorfon, 40 mg/kg (n = 1); a mixture of TBZ at 44 mg/kg with piperazine (PPZ) at 55 mg of base/kg (n = 1); febantel (FBT), 6 mg/kg (n = 3), 12 mg/kg (n = 1), or 24 mg/kg (n = 1); and pyrantel (PRT) pamoate, 6.6 mg of base/kg (n = 1). Large strongyles, Strongylus vulgaris (9 horses) and S edentatus (5 horses), were effectively removed...
Bowman KF, Leitch M, Nunamaker DM, Fackelman GE, Tate LP, Park MI, Boles CL, Raker CW.A total of 19 Thoroughbred horses were treated for traumatic disruption of the suspensory apparatus, using either external support of the injured limb, removal of fractured proximal sesamoid bone fragments, metacarpophalangeal arthrodesis, compression screw fixation of the fractured proximal sesamoid bones, application of a cast-brace attached to a transfixation pin inserted through the third metacarpal bone, or combinations thereof. Major complications during the treatment of traumatic disruption of the suspensory apparatus were infection (9 of 19 horses, 47%), large cast sores (10 of 14 trea...
Slusher SH, Freeman KP, Roszel JF.In a review of specimens from 80 mares with concurrently collected endometrial biopsy and cytology preparations, eosinophils were found in 33 specimens from 27 mares. In 22 of 27 mares, there were conditions predisposing to pneumovagina, which presumably led to pneumouterus. Thirty-two of the 80 mares also had conditions predisposing to pneumovagina but no eosinophils in the uterine specimens. Experimental introduction of air into the uterus of 3 mares resulted in eosinophils in their uterine specimens.
Bürki F, Nowotny N, Rossmanith W, Pallan C, Möstl K.During 3 foaling seasons around 150 Lipizzaner foals were vaccinated against ERP with commercial vaccines and groups thereof were serotested in CF and SN for their humoral immune response. In addition, 6 horses of cheaper common breeds were vaccinated on the University premises, were continuously serologically screened and subjected to virulent nasal test infection. The live-virus vaccine Prevaccinol interfered so profoundly and up to the 20th week of life with maternal antibodies that its further use was discontinued. The inactivated vaccine Pneumabort-K proved to be of impressive immunogenic...
Brown VA, Wilkins PA.Techniques for novel approaches to the diagnosis and management of equine pulmonary disease continue to be developed and used in clinical practice. Diagnostic techniques involving immunoassays and nucleic acid-based tests not only decrease the time in which results become available but increase the sensitivity and specificity of test results. These assays do not substitute for careful clinical evaluation but can shorten the time to a confirmed accurate diagnosis, and thus allow for early initiation of therapeutic strategies and prevention protocols. With further understanding of the molecular ...
Watson ED, Stokes CR, Bourne FJ.Acute endometritis was induced in ovariectomized pony mares by infusion of a 1% solution of oyster glycogen. Maximum concentrations of immunoreactive leukotriene B4 in uterine washings coincided with the greatest rate of infiltration of neutrophils into the uterine lumen. Concentrations of immunoreactive leukotriene B4 decreased to basal levels 6 h after infusion and were unaffected by administration of ovarian steroids to ovariectomized mares. Uterine washings from mares with persistent endometritis did not contain significantly different concentrations of leukotriene B4 from genitally normal...