The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Little D, Keene BW, Bruton C, Smith LJ, Powell S, Jones SL.A 49-kg (107.8-lb) sexually intact male Arabian foal was evaluated at 3 days of age because of profuse watery diarrhea, anorexia, and signs of abdominal pain. Physical examination findings were unremarkable except for evidence of diarrhea. A catheter was placed in the right jugular vein for administration of antimicrobials and lactated Ringer's solution. The foal was discharged with instructions to the owner to continue antimicrobial administration and fluid therapy; at home, the owner inadvertently cut the catheter at the level of the hub during attempted removal, and the catheter fragment mi...
Cook AG, Maxwell VB, Donaldson LL, Parker NA, Ward DL, Morrow JK.To determine whether antibodies against Sarcocystis neurona could be detected in CSF from clinically normal neonatal (2 to 7 days old) and young (2 to 3 months old) foals. Methods: Prospective study. Methods: 15 clinically normal neonatal Thoroughbred foals. Methods: Serum and CSF samples were obtained from foals at 2 to 7 days of age and tested for antibodies against S. neurona by means of western blotting. Serum samples from the mares were also tested for antibodies against S. neurona. Additional CSF and blood samples were obtained from 5 foals between 13 and 41 days after birth and between ...
Foote CE, Love DN, Gilkerson JR, Whalley JM.Equine herpesvirus 1 (EHV-1) is a major cause of respiratory disease and abortion in horses worldwide. Although some vaccines have been shown experimentally to reduce disease, there are few reports of the responses to vaccination in the field. This study measured antibody responses to vaccination of 159 mares (aged 4-17 years) and 101 foals (aged 3-6 months) on a large stud farm with a killed whole virus EHV-1/4 vaccine used as per the manufacturer's recommendations. Using an EHV glycoprotein D (gD)-specific ELISA and a type-specific glycoprotein G (gG) ELISA, respectively 13.8 and 28.9% of ma...
Hess MB, Parker NA, Purswell BJ, Dascanio JD.Lufenuron, a benzoylphenyl urea derivative, was evaluated as a treatment for endometrial fungal infections in 4 mares. Intrauterine lavage was performed with lufenuron suspended in sterile saline (0.9% NaCl) solution. Cytologic evaluation and fungal culture of the endometrium, as well as subsequent reproductive performance, were used to monitor efficacy of this treatment. Fungal endometritis in mares is associated with infertility. Treatment is often ineffective and costly, and recurrence following treatment is not uncommon. Intrauterine infusions of lufenuron were effective in eliminating fun...
Kolm-Stark G, Wagner R.Icelandic horses in Austria are commonly affected by an allergic inflammatory skin disease recurring during the summer seasons, which shares characteristic features with Culicoides hypersensitivity. However, the causative agents have not yet been identified. Therefore, intradermal skin testing (IDST) with a standardised extract of Culicoides variipennis and 21 other allergens relevant within Austria was performed in 81 Icelandic horses. All horses included into the study were treated regularly with ivermectin and had no history of administration of anti-inflammatory drugs. Forty-three of these...
Dyer J, Fernandez-Castaño Merediz E, Salmon KS, Proudman CJ, Edwards GB, Shirazi-Beechey SP.Dietary carbohydrates, when digested and absorbed in the small intestine of the horse, provide a substantial fraction of metabolisable energy. However, if levels in diets exceed the capacity of the equine small intestine to digest and absorb them, they reach the hindgut, cause alterations in microbial populations and the metabolite products and predispose the horse to gastrointestinal diseases. We set out to determine, at the molecular level, the mechanisms, properties and the site of expression of carbohydrate digestive and absorptive functions of the equine small intestinal brush-border memb...
Uhl EW, Giguère S, Jack TJ, Hodge T.Previous studies revealed that foals inoculated with virulent Rhodococcus equi had significantly higher pulmonary levels of interleukin-1beta, interleukin-12 p40, interferon-gamma, and tumor necrosis factor-alpha mRNA compared to foals inoculated with an avirulent plasmid-cured derivative. The purpose of this study was to determine if the increases in cytokine expression were associated with increased pulmonary activation of nuclear factor-kappaB (NF-kappaB). Electrophoretic mobility shift assays were performed on pulmonary nuclear protein extracted from foals treated with phosphate-buffered s...
van Maanen C.Equine herpesvirus 1 (EHV1) and equine herpesvirus 4 (EHV4) are important ubiquitous equine viral pathogens, causing much damage to the horse industry. EHV1 strains are associated with respiratory disease, abortion, and paresis/paralysis, whereas EHV4 strains are predominantly associated with respiratory disease. In the past decades much research effort has been put into improving knowledge about these viruses. In this paper the current state of knowledge of these viruses and the most important aspects of these virus infections, e.g. epidemiology, clinical aspects, pathogenesis and pathology, ...
Ohnesorge B, Gehlen H, Wohlsein P.Description of transendoscopic electrosurgical treatment of a pulmonary granular cell tumor in a horse. Methods: Case report. Methods: A 12-year-old Standardbred mare. Methods: After endoscopic examination and transendoscopic biopsy, a granular cell tumor nodule was removed transendoscopically from the right principal bronchus of the sedated horse (0.02 mg/kg detomide intravenous) with a monopolar electrosurgical wire snare. Two days later, the surgical area was irradiated transendoscopically using a Nd-YAG laser. Results: After surgery, the horse had no further signs of respiratory disease. C...
Moore BD, Balasuriya UB, Hedges JF, MacLachlan NJ.Equine viral arteritis (EVA) is an endotheliotropic viral disease of horses caused by equine arteritis virus (EAV). Although there is only one serotype of EAV, there is marked variation in the virulence of different strains of the virus. The replication and cytopathogenicity of three well-characterized strains of EAV of different virulence to horses were compared in rabbit kidney (RK-13) and primary equine pulmonary artery endothelial cells (ECs). Viral protein expression, plaque size, and cytopathogenicity of all three viruses were similar in RK-13 cells, whereas two virulent strains of EAV w...
Mizukoshi F, Maeda K, Hamano M, Iwata H, Matsumura T, Kondo T, Sugiura T.In this study, IgG subclass responses against equine herpesvirus type 4 (EHV-4) were examined by enzyme-linked immunosorbent assay (ELISA) using a type-specific region of EHV-4 glycoprotein G (gG). ELISA using sera collected from horses experimentally infected with EHV-4 revealed that IgGa and IgGb antibodies were detected at high level, but IgGc and IgG(T) antibody responses were detected at low level or were undetectable. The IgGa antibody response reached its peak on day 10 post-infection, and then dropped. The IgGb antibody response reached its maximum level on day 12 post-infection, and t...
Palacios H, Hibarren I, Olalla MJ, Cala V.The diagnosis of lead poisoning in horses living on farmland in the vicinity of a battery recycling plant was based on clinical signs as well as on laboratory findings. Chemical analysis of six surface soils (0-15 cm) and herbage samples taken at different distances to the recycling plant showed very high total lead levels in the closest sites to the facility and a clear decrease with distance. Total lead levels in soil samples ranged from 127 to 5657 mg kg(-1), with more than 70% of lead extractable by EDTA in the most polluted soils. Lead levels in the aerial part of herbage samples were in ...
Collins ND, LeRoy BE, Vap L.Extremely high bicarbonate (HCO3-) and anion gap values were measured in two horses and a calf using the Hitachi 911 automated serum biochemistry analyzer. All three animals had severe muscle disease as evidenced by markedly increased aspartate aminotransferase and creatine kinase activities. Laboratory error was suspected as the source of the increased HCO3- because values calculated from blood gas analysis were normal. It was hypothesized that increased serum lactate dehydrogenase (LDH) activity and pyruvate concentration overwhelmed the oxamate LDH inhibitor in the enzymatic HCO3- assay, re...
Dixon JB, Savage M, Wattret A, Taylor P, Ross G, Carter SD, Kelly DF, Haywood S, Phythian C, Macintyre AR, Bell SC, Knottenbelt DC, Green JR.A condition resembling acquired immunodeficiency with anemia has been described in British Fell pony foals. The pathogenesis is unknown. The present study involved 322 foals of which 164 were of Fell breed and 12 were affected. Discriminant and multiple regression analyses were used to test the results of all clinical pathology parameters from these foals for statistical association with (1) breed origin and (2) presence of disease. Only hematocrit associated significantly with presence of disease. However, significant associations were found with Fell breed origin, including serum albumin con...
Henson KL, Alleman AR, Kelley LC, Mahaffey EA.Immunohistochemical techniques were used to examine 29 cases of equine lymphoma for estrogen receptor (ER) and progesterone receptor (PR) expression. The lymphomas examined included T-cell-rich large B-cell lymphomas, B-cell neoplasms, and T-cell lymphomas. The individual cases were also classified according to the anatomic location of the tumors. One normal equine lymph node was also examined for ER and PR expression. All of the cases of equine lymphoma and the normal lymph node were negative for Er. A total of 16/29 (55%) PR-positive lymphomas were identified. Seven of the 12 (58%) T-cell-ri...
Inoue Y, Yamaguchi K, Sawada T, Rivero JC, Horii Y.Borna disease virus (BDV)-specific antibodies were monitored in Misaki feral horses annually for 4 years using an electrochemiluminescence immunoassay (ECLIA). Among 130 horses examined, 35 (26.9%) with an ECLIA count above 1000 once or more were judged as BDV seropositive. Throughout the study period, p24 antibodies were more frequent than p40 antibodies in almost all positive animals. Among the 35 seropositive horses, the ECLIA count was consistently high in 12 cases. Eleven horses seroconverted from negative to positive and 7 underwent reversal. The count in the remaining 95 horses (73.1%) ...
Garton NJ, Gilleron M, Brando T, Dan HH, Giguère S, Puzo G, Prescott JF, Sutcliffe IC.Rhodococcus equi is a major cause of foal morbidity and mortality. We have investigated the presence of lipoglycan in this organism as closely related bacteria, notably Mycobacterium tuberculosis, produce lipoarabinomannans (LAM) that may play multiple roles as virulence determinants. The lipoglycan was structurally characterized by gas chromatography-mass spectrometry following permethylation, capillary electrophoresis after chemical degradation, and (1)H and (31)P and two-dimensional heteronuclear nuclear magnetic resonance studies. Key structural features of the lipoglycan are a linear alph...
Malone E, Graham L.Choice of an analgesic for gastrointestinal pain requires consideration of the cause of the pain, desired duration of pain relief, need for sedation, and potential side effects and toxicity, particularly in light of other drugs being used and effects on the gastrointestinal tract. It is imperative that close monitoring be continued to ensure that surgical lesions or worsening conditions are detected. Recent research in the field may lead to new drugs, drug combinations, and avenues of treatment that minimize the side effects of these drugs while maximizing their efficacy.
Dowdall SM, Matthews JB, Mair T, Murphy D, Love S, Proudman CJ.Equine clinical larval cyathostominosis is caused by simultaneous mass emergence of previously inhibited larvae from the mucosa of the colon. Clinical signs include diarrhoea, colic, weight loss and malaise, and in up to 50% of cases, the disease results in death. Cyathostominae spend a large part of their life cycle as larval stages in the intestinal mucosa. Definitive diagnosis is difficult due to the lack of diagnostic methods for pre-patent infection. In the present study, the enzyme-linked immunosorbent assay (ELISA) was used to investigate isotype responses to larval cyathostominae somat...
Nordengrahn A, Merza M, Ros C, Lindholmc A, Palfl V, Hannant D, Belák S.Equineherpesvirustypes 2 and 5 (EHV-2andEHV-5)have a rather unclearpathogenicity and distribution within the equid population. In order to gain more information on the prevalence of these two viruses, type-specific PCR assays were developed to detect viral DNA in nasal specimens and in peripheral blood leukocytes (PBLs) of adult horses and foals from various regions of Europe, i.e. Sweden, Hungary and the United Kingdom. In adult horses, the prevalence of EHV-2 in PBLs was up to 68% in Sweden and 71% in the United Kingdom. EHV-2 DNA was detected in the PBLs from all the foals tested in all cou...
Chiesa OA, Cuenca R, Mayayo E, Guarro J, Santamaria J, Stchigel AM.To evaluate the cytological and microbiological contents of guttural pouch washes of ten randomly selected horses restrained so as to prevent them lowering their heads, and to assess the possible effects on the guttural pouch environment in these horses. Methods: Cytological and microbiological studies were performed on guttural pouch washes of ten clinically normal horses restrained in a standing position so as to prevent them from lowering their heads below normal, as would happen during transportation on long journeys. They were restrained for 12 or 24 h and cytological, bacteriological and...
Reuss SM, Chaffin MK, Schmitz DG, Norman TE.The sonographic characteristics of intraabdominal abscesses in 11 foals and intraabdominal lymphadenitis in five foals with Rhodococcus equi infections are presented. Intraabdominal abscesses were usually present in the ventral abdomen adjacent to the ventral body wall, well-marginated, and contained a mixed or complex echo pattern. Lymphadenitis appeared as singular or multiple clusters of lymph nodes of mixed echogenicity adjacent to any portion of the gastrointestinal tract or body wall. Sonographic findings were supported by necropsy examinations, but sonographic measurements consistently ...
Cohen ND, Loy JK, Lay JC, Craig TM, McMullan WC.A 3-year-old Quarter Horse gelding admitted for evaluation of weight loss, signs of depression, and dermatitis of the coronary bands was found to have eosinophilic gastroenteritis. Intralesional nematodes identified as Strongylus edentatus were seen in multiple microscopic sections of the small colon, suggesting a parasitic cause of the disease.
Perryman LE, McGuire TC, Hilbert BJ.Selective immunoglobulin M deficiency was diagnosed in 5 foals, on the basis of reduced serum immunoglobulin M concentrations (more than 2 standard deviations below the normal mean). All 5 foals had clinical signs or lesions involving the respiratory tract. Lkebsiella sp was isolated from joint fluids, bronchial lymph nodes, or tracheal washings from the 3 foals in which such samples were available for microbiologic evaluation.
Oleksiewicz MB, Snijder EJ, Normann P.A putative zinc finger (ZF) domain in the Equine arteritis virus (EAV) nsp1 protein was described recently to be required for viral transcription. The nsp1 ZF (50 aa) was expressed on the surface of M13KE gIII phage, fused to the N terminus of the phage pIII protein. To evaluate the functionality of the ZF domain, a binding assay was developed, based on the use of immobilized Ni(2+) ions (Ni-NTA). Phages displaying ZF bound significantly better to Ni-NTA than did phages displaying negative-control peptides, which also contained metal-coordinating residues. Also, binding of ZF-displaying phages...
Sanchez S, Studer M, Currin P, Barlett P, Bounous D.Listeria monocytogenes is ubiquitous in the environment but is rarely reported as a cause of keratitis in animals. In this case, a mare was presented with epiphora and evidence of pain in the right eye. Listeria monocytogenes was isolated from a corneal lesion, and bacteria were also seen in the cytologic evaluation. This is the first reported case of ulcerative keratitis associated with L. monocytogenes in a horse.
Parente EJ, Richardson DW, Spencer P.Medical records of 57 horses admitted between 1980 and 1991 because of basal sesamoidean fractures were evaluated. Radiographic measurements of fragment size and fracture characteristics were recorded to determine their relationship to outcome. A successful outcome was assessed on the basis of the ability to return to racing, ability to race more than one time, and ability to finish first, second, or third. Any change in racing class also was assessed. There was a significant (P < 0.001) overrepresentation of Thoroughbreds, compared with other breeds in the hospital population. Fractures of...
Hnátková Z, Vraný B, Hnátek J, Lettl A.The preparation of toxic cultures of Clostridium septicum is described, using an apparatus with a straight dialysis tubing, where the medium is filled both into the nutrition and cultivation space of the apparatus. Using the cultivation to nutrition volume rate 1:2, mean titre of lethal antigen in filtrates 3.86 limes mortis per mL and 300 dosis lethalis minima per Lm was obtained in comparison with the values of 2.22 and 150 respectively in flask filtrates. Native filtrates of dialyzed cultures were better antigens for hyperimmunization of horses than the culture filtrates from flasks.
Rothenbuhler R, Hawkins JF, Adams SB, Lescun TB, Weil AB, Glickman LT, Fessler JF, Glickman NG.To determine whether heavy (> or = 680 kg [> or = 1,500 lb]) draft horses undergoing surgical treatment for acute signs of abdominal pain were at a greater risk for anesthetic and postoperative complications and lower postoperative survival rates than light ( 1 year) follow-up information was available was 50%. Conclusions: Draft horses weighing > 680 kg that underwent surgery because of acute signs of abdominal pain had longer durations of anesthesia, more postoperative complications, and higher mortality rates than draft horses weighing < 680 kg.
Toribio RE.A number of viruses transmitted by biological vectors or through direct contact, air, or ingestion cause neurologic disease in equids. Of interest are viruses of the Togaviridae, Flaviviridae, Rhabdoviridae, Herpesviridae, Bornaviridae, and Bunyaviridae families. Many are classified as arboviruses because they use arthropod vectors, whereas others are transmitted directly via ingestion, inhalation, or integument damage. The goal of this article is to provide an overview on pathophysiologic and clinical aspects of arboviruses of equine importance, including alphaviruses (Togaviridae) and flaviv...
McCann SH, Mumford JA, Binns MM.A search for variable restriction sites has been carried out for equine herpesvirus-1 (EHV-1) in an attempt to develop markers which can be used to group epidemiologically related viruses into groups, and to learn more about the dynamics of EHV-1 disease. Crude viral DNA extracts of EHV-1, prepared by Hirt extraction, were digested with AluI, HaeIII, or RsaI, and Southern blotted following electrophoresis. DNA fingerprints, produced by probing the Southern blots with the EHV-1 EcoR1-I fragment, separated 56 isolates into 16 groups. The variable sites within the EcoR1-I fragment were mapped app...
Bauer C.The prevalence of Eimeria leuckarti infection and the intensity of faecal oocyst output were determined in a herd of 14 mares and their foals in northwest Germany using a sedimentation technique at weekly intervals during a summer grazing season from May to September. None of the mares, but all foals shed oocysts on at least one occasion. The patent periods lasted up to 16 weeks. The mean intensity of oocyst output (0.1-33 o.p.g.) was very low. No clinical signs of gastrointestinal disorder were noticed in any of the foals during this study.
Yapklç O, Yavru S, Kale M, Bulut O, Simşek A, Sahna KC.In this study, 162 horses, 80 donkeys and 51 mule serum samples were collected in Konya city. Additionally, 64 horse serum samples from Ankara and 49 samples from Kayseri city were included in the study. A total of 406 serum samples were examined by agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent assay (ELISA) for antibody to equine infectious anaemia virus (EIAV) and no positive result was detected.
Harvey-Micay J.An 8-year-old, Thoroughbred-cross mare presented with recurrent colic. Exploratory laparotomy revealed a large mass near the right dorsal colon; white, raised foci on the liver; and enlarged mesenteric lymph nodes. Cytological examination of biopsies revealed neoplastic cells. The diagnosis of adenocarcinoma was confirmed by histological examination.
Corbeil LE, Morrissey JF, Léguillette R.This report describes 5 horses in the southern Alberta region with typical and atypical external abscessation due to Corynebacterium pseudotuberculosis (pigeon fever). "Pigeon fever" has recently been diagnosed in new geographic regions in North America and should be kept as a differential diagnosis by practitioners when an external or internal abscess is identified in a horse. L’infection parCorynebacterium pseudotuberculosis(fièvre du pigeon) chez les chevaux est-elle une maladie émergente dans l’Ouest canadien? Ce rapport décrit cinq chevaux dans la région sud de l’Alberta atteint...
Drozdzewska K, Potocnik E, Schwarz B.Placing a nasogastric tube can be a life-saving act for a horse but is considered an occupational hazard for veterinarians. An online questionnaire was performed to assess and specify potential risks. 123 equine veterinarians completed the survey, and the majority admitted using the mouth to handle the end of the nasogastric tube (sucking or blowing air) and having accidentally swallowed or aspirated stomach content or medications. This can potentially lead to aspiration pneumonia or pneumonitis. Mineral oil seems to be especially dangerous as aspiration may be asymptomatic at the beginning an...
Tanaka S, Kaji Y, Taniyama H, Matsukawa K, Ochiai K, Itakura C.Typical Pneumocystis carinii pneumonia was found in a male thoroughbred foal (46 days old) suffering from diarrhea and hypogammaglobulinemia after birth. The characteristics of the organisms were demonstrated by Grocott methenamine silver staining, and scanning and transmission electron microscopy. The present focal had no histological lesions suggesting immunodeficiency. However, he could not get adequate colostrum from his dam, because she died of hemorrhagic shock due to immuno-mediated thrombocytopenia at delivery. This condition was considered to have predisposed the foal to the pneumonia...
Khoury C, Manilla G, Maroli M.The following 13 species of ticks, belonging to Ixodidae family, were recorded in Italy on horse (Equus caballus) since 1931: Ixodes ricinus, I. gibbosus, Haemaphysalis inermis, H. parva, H. punctata, H. sulcata, Dermacentor marginatus, Rhipicephalus sanguineus, Rh. bursa, Rh. turanicus, Hyalomma marginatum, Hy. detritum, Boophilus annulatus. The regional distribution and the role of the species in the transmission of pathogens are reported.
Marolt J, Naglić T, Hajsig D.A case of a spontaneous mycokeratitis of a previously injured cornea in a horse is described. The infection was caused by Aspergillus oryzae. After application of Chloramphenicol ophthalmic ointment a corneal clouding was found in the centre which was circularly sharply defined and which - after dispensing Dexamethason-Neomycin eye drops - expanded all over to a purulent keratitis. The demarcated and initially non purulent mycotic lesions largely improved after the application of tincture of iodine, whereas the purulent keratitis could be completely cured only by a lasting treatment with Lugol...