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.
MacKay RJ, King RR, Dankert JR, Reis KJ, Skelley LA.Blood monocytes and alveolar macrophages (AM) were harvested from foals (aged 46 days to 6 months) and cultured in either medium alone or medium containing 10 micrograms/ml bacterial lipopolysaccharide (LPS). After 24 h, culture supernates were collected and analyzed for cytotoxic activity on sensitized L929 cells. Both monocytes and AM that had been treated with LPS produced significantly more cytotoxic activity than the same cell type exposed to medium lacking LPS. LPS-treated macrophages secreted significantly more cytotoxic activity (120 +/- 17.8 U/ml) than did LPS-treated monocytes (47.3 ...
Charlton C, Tulleners E.Two male racehorses (1 Standardbred, 1 Thoroughbred) were examined because of intraluminal cervical tracheal lesions, located 60 to 70 cm from the nares. A contact neodymium:yttrium aluminum garnet laser with a chisel probe attached to the fiber end was used to transendoscopically debride a nonhealing tracheal ulcer and to excise a pyogranulomatous mass. In both horses, the surgical sites healed quickly and the lesions did not redevelop.
Halldórdsóttir S, Larsen HJ.A survey of summer eczema was conducted on 391 Icelandic horses in Norway. The study showed a prevalence of summer eczema of 17.6 per cent in the horses investigated. Icelandic horses born in Norway where shown to be less affected with summer eczema than imported horses, 8.2 per cent and 26.9 per cent respectively (P less than 0.001). There was no difference in the prevalence of summer eczema relative to gender or colour of the horse. The number of horses affected with summer eczema rose with increasing age and the number of years which had elapsed since importation. On average, Icelandic hors...
Warko G, Bostedt H.Eight vital, new-born foals were additionally administered a non-species-specific colostrum-substitute via stomach-tube within the first 18 hours of their life. The substitute had been made of cattle-colostrum. These foals as well as a control-group of eight foals constantly had free access to maternal colostrum. Object of measurement was GGT-activity in the blood-serum. The increase of GGT-activity within the first 24 hours after birth was very low in the control-group (up to 25 U/l), and very high in the tested animals (418 +/- 182 U/l). Obviously there is a direct connection between this ri...
Orsini JA, Nunamaker DM, Jones CJ, Acland HM.A large oral squamous cell carcinoma in a 27-year-old Arabian stallion was removed by partial excision of the incisive bone. There was no gross evidence of recurrence or metastasis 5 months later.
Posnett ES, Fehrsen J, De Waal DT, Ambrosio RE.The ability of the Babesia equi repetitive probes, pSE2 and pSB20, to detect parasites in blood from experimentally infected, naturally infected and carrier animals was tested using a spot hybridization assay. The clinical course of the experimentally infected horses was monitored using microscopy, indirect fluorescent antibody tests, packed cell volume, temperature and the probe assay. The probes sensitively monitored the parasite level during the development of the disease and correlated well with the other parameters tested. The sensitivity of the probe assay was superior to that of light m...
Madelin TM, Clarke AF, Mair TS.Sera from 54 two- to three-year-old Thoroughbred horses from an English racing stable were examined for precipitins to antigen extracts prepared from 18 species of moulds (fungi and thermophilic actinomycetes) isolated from the same stable. Twenty-seven horses exhibited serum precipitins to one or more antigens; sixteen of the mould antigens elicited positive reactions in sera from one or more horses. Significantly more precipitins occurred in sera of those horses stabled in a barn than among those stabled in individual boxes. This indicated a possible association between type of housing, leve...
Ogunnariwo JA, Alcantara J, Schryvers AB.Two clinical isolates of Pasteurella multocida associated with bovine pneumonia were examined for iron acquisition. Both isolates were capable of obtaining iron for growth from bovine but not from human, avian, equine or porcine transferrin. This correlated with specific binding of bovine transferrin by iron-limited cells or isolated membranes. No siderophore was detected in the strains by a general screening assay. In response to iron-limited conditions, a number of high molecular mass iron-regulated outer membrane proteins were produced including an 82 kDa receptor protein which was affinity...
Zicker SC, Spensley MS, Rogers QR, Willits NH.Concentrations of amino acids in the plasma of 13 neonatal foals with septicemia were compared with the concentrations of amino acids in the plasma of 13 age-matched neonatal foals without septicemia. Analysis of the results revealed significantly lower concentrations of arginine, citrulline, isoleucine, proline, threonine, and valine in the plasma of foals with septicemia. The ratio of the plasma concentrations of the branched chain amino acids (isoleucine, leucine, and valine) to the aromatic amino acids (phenylalanine and tyrosine), was also significantly lower in the foals with septicemia....
van der Kolk JH, Klein WR, van der Putten SW, Mol JA.A thirteen-year-old Dutch warmblooded mare was referred to the Faculty of Veterinary Medicine because of a sinusitis. She was thin with a potbellied appearance. Her coat was dull with long wavy hair. Unilateral (left) purulent nasal discharge was evident. A cbc revealed leucopenia (3.9 G.L.-1) and plasma biochemical analysis revealed a plasma glucose concentration of 10.1 mmol.L-1. Thermostable alkaline phosphatase (at 65 degrees C during 2 minutes) could not be demonstrated. Basal plasma cortisol concentration was lowered (114 nmol.L-1) and basal plasma ACTH concentration was highly elevated ...
Berry CR, O'Brien TR, Madigan JE, Hager DA.Clinical records and thoracic radiographs of 19 horses with a confirmed pathologic diagnosis of silicosis were reviewed. These horses had histories of varying degrees of chronic weight loss, exercise intolerance, and respiratory distress. At the time of presentation, two horses were asymptomatic. Ten horses were geldings and nine were female. The mean age of the 19 horses was 10.7 +/- 5.5 years. Fourteen horses were identified as being from the Monterey-Carmel Peninsula of midcoastal California. An abnormal, structured interstitial pulmonary pattern was identified on thoracic radiographs in ea...
Van Oirschot JT, Bruin G, de Boer-Luytze E, Smolders G.Foals that were born to mares vaccinated twice a year against influenza had moderate to high haemagglutination-inhibition antibody titers at 24 hours after birth. The foals were vaccinated at six and ten weeks of age, and again at three to five months after birth. Four months after the third vaccination no antibodies against A/H7N7 and A/H3N8 influenza viruses were detected in these foals. Thus, maternal antibodies probably prevented the development of antibodies against equine influenza virus after vaccination. Foals born to the same mares one year later were monitored to determine the rate o...
Davis DM, Honnas CM, Hedlund CS, Schneiter HL.A 3-day-old Thoroughbred foal developed a large, air-distended, midcervical swelling that was diagnosed as a congenital tracheal bronchus with associated ectopic lung tissue. Clinical signs consisted of a compressible air-filled sac that enveloped the trachea. The nature and extent of the defect were evaluated endoscopically and radiographically. Surgical resection of the bronchus and associated air-filled sac resulted in a functionally and cosmetically acceptable outcome.
Teifke JP, Weiss E.Unfixed and formalin-fixed frozen sections and paraffin-sections of histopathologically confirmed sarcoids of 20 horses were studied in the PCR. The used set of primers was located in the E5 open reading frame fitting both to bovine papillomavirus 1 (BPV-1) and BPV-2. Independent of the quality of the used tissues BPV-DNA was detected in all 20 sarcoids. By cleaving with restriction endonuclease Bst XI it was shown that the DNA-sequences amplified by PCR were identical with that of BPV-1. The results support the general view that BPV play an important role in equine sarcoids.
Stitz L, Richt JA, Rott R.An overview of the pathogenesis of Borna disease (BD) in rats as a model for the naturally occurring infection in horses and sheep is presented. Our findings revealed a virus infection in which a virus-specific T cell-mediated immune response leads to disease. The immune cells capable of mediating this immunopathological reaction were defined as helper/inducer T cells. In all, the described observations indicate that CD4+ T cells and macrophages trigger a delayed-type hypersensitivity reaction and cause BD together with other cells of the immune system.
Van Rensburg IB, Collett MG, Ronen N, Gerdes T.An adult stallion presented with a severe papular dermatitis of especially the neck, chest and genitalia. A marked scrotal oedema was present. Histopathological examination of skin biopsies, revealed the presence of numerous intracytoplasmic molluscum bodies in areas of focal epidermal hyperplasia. Electron microscopical examination showed the presence of typical pox virions in affected epidermal cells. Attempts at viral isolation were unsuccessful. This is believed to be the first reported case of molluscum contagiosum in a horse in the Republic of South Africa.
Posnett ES, Ambrosio RE.A genomic library of Babesia caballi DNA was constructed in the plasmid vector pUC13. The specificity of the clones for B. caballi was established by the lack of hybridization to Babesia equi, Babesia bovis, Babesia bigemina and equine DNA. Two probes, pBC11 and pBC191, were isolated that could detect 0.25 ng and 0.125 ng of B. caballi DNA, corresponding to a parasitaemia of 0.12% and 0.06% respectively. pBC191 could detect B. caballi parasites in the blood of an experimentally infected horse as well as in naturally infected horses.
Ross PF, Rice LG, Plattner RD, Osweiler GD, Wilson TM, Owens DL, Nelson HA, Richard JL.Ninety-eight samples of feeds associated with 44 cases of equine leukoencephalomalacia (ELEM) and 83 samples of feed associated with 42 cases of a porcine pulmonary edema syndrome (PPE) were analyzed for fumonisin B1 (FB1). For comparison purposes, 51 feed samples not associated with PPE or ELEM were also analyzed. Feed associated with ELEM contained FB1 ranging from less than 1 microgram/g to 126 micrograms/g with 75% of the cases having at least 1 sample above 10 micrograms/g. Feeds associated with PPE ranged from less than 1 microgram/g to 330 micrograms/g with 71% of the cases having at le...
Seahorn JL, Slovis NM, Reimer JM, Carey VJ, Donahue JG, Cohen ND.To identify factors significantly associated with an epidemic of fibrinous pericarditis during spring 2001 among horses in central Kentucky. Methods: Case-control study. Methods: 38 horses with fibrinous pericarditis and 30 control horses examined for other reasons. Methods: A questionnaire was developed to solicit information regarding a wide range of management practices and environmental exposures from farm owners or managers. Results: The following factors were found in bivariate analyses to be significantly associated with an increased risk of pericarditis: being from a farm with mares an...
Gerard MP, Bowman KF, Blikslager AT, Tate LP, Bristol DG.To determine whether complete cecal bypass, by jejunocolostomy or ileocolostomy, is an effective treatment for horses with cecal impaction. Methods: Retrospective analysis of medical records. Methods: 9 horses with cecal impaction managed by jejunocolostomy (3) or ileocolostomy (6) performed with or without typhlotomy for evacuation of cecal contents. Methods: Information on age, breed, gender, duration of medical treatment, preoperative abnormalities, surgical procedure, and postoperative complications was retrieved from the medical records. Follow-up data were obtained via telephone intervie...
Rizzo D.An 11-year-old crossbred mare was presented with left eye buphthalmia, a mydriatic minimally responsive pupil, locally extensive ventral corneal edema, and corneal striae. Intraocular pressures exceeding 80 mmHg lead to a presumptive diagnosis of glaucoma. Following several days of treatment there was no improvement and enucleation was performed. Glaucome idiopathique chez une jument de race croisée âgée de 11 ans. Une jument de race croisée âgée de 11 ans a été présentée avec une buphtalmie de l’œil gauche, une pupille mydriatique minimalement réactive, un œdème cornéen ventr...
Kohn CW, Swardson C, Provost P, Gilbert RO, Couto CG.Myeloid and megakaryocytic bone marrow hypoplasia in association with moderate to profound neutropenia was observed in 8 young Standardbred horses sired by the same stallion; 7 horses were intermittently thrombocytopenic. Evaluation of serial neutrophil counts in 2 horses suggested that a cyclic variation in neutrophil numbers was present, that lymphocyte numbers increased when neutrophil counts decreased, and that platelet counts decreased when neutrophil counts decreased. Preliminary bone marrow cultures indicated that myeloid progenitor cells were present and that these cells were able to r...
Riedesel DH, Hildebrand SV.A syndrome similar to malignant hyperthermia developed in a 545-kg Quarter Horse while anesthetized with halothane for cataract removal. Succinylcholine administration caused prolonged, severe muscle fasciculations followed by tachycardia, and an elevated blood pressure. Later, while the horse was still under anesthesia, its body temperature rose 2 degrees C, and respiratory acidosis developed. Myositis developed after surgery, but the horse recovered.
Andrews FM, Hamlin RL, Stalnaker PS.Whole blood viscosity (WBV) was measured on six healthy horses and ten horses presented for colic surgery. A Wells-Brookfield cone-and-plate microviscometer at 6 rpm was used to determine WBV and WBV was adjusted for packed cell volume (PCV). The ten colic horses were divided into two groups: five horses that died or were euthanatized (group 1) and five horses that were discharged after surgery and medical therapy (group 2). The mean WBV for each group was compared using analysis of variance followed by Duncan multiple-range tests. Mean WBV of group 2 (5.81 +/- 1.48 centipoise [cp]) and normal...
Kalinowski M, Grądzki Z, Jarosz Ł, Adaszek Ł.Rhodococcus equi (R. hoagii) is an opportunistic pathogen commonly found in foals up to 6 months old and animal environment. The R. equi genome contains genetically stable chromosomal DNA and an 80-90 kb plasmid containing vapA gene, responsible for virulence. Most reports from around the world focus on the determination of R. equi plasmid profiles. Few studies have attempted to determine differences in nucleotide sequences between virulent strains of R. equi isolated from foals and breeding environment. The aim of the study was to perform a molecular analysis of a fragment of the chromosomal ...
Adeyefa CA.The effects of the various growth factors with regard to the nutritional physiology of zoophilic dermatophytes isolated from horses are reported. The optimum temperature, pH and growth period for the fungal isolates were found to be 30 degrees-35 degrees C, 5-6 and 7-12 days respectively while the carbon and nitrogen sources utilised by the organisms were sucrose, fructose, maltose, L-arginine and calcium nitrate. The use of these factors in preparation of efficacious fungicides used in the treatment of ringworm infections in man and animals is discussed.
Mendoza FJ, Mejia-Moreira S, Buchanan BR, Toribio RE, Perez-Ecija A.Insulin dysregulation (ID) and donkey metabolic syndrome (DMS) are common in this species. Contrary to horses, diagnostic guidelines compiling insulin cut-offs values and dynamic testing interpretations have not been reported for this species. Objective: To evaluate resting serum insulin concentrations, the combined glucose-insulin test (CGIT) and the glucose intravenous tolerance test (IVGTT) for the diagnosis of DMS with ID suspicion. Methods: Diagnostic test comparison. Methods: Six of 80 mix-breed adult donkeys fulfilled the inclusion criteria for DMS based on history or clinical evidence ...
Kim YK, Noh KB, Han CS, Moon JY, Yoon DK, Song KJ, Kim DJ, Kubera M, Maes M, Song JW.Borna disease virus (BDV) predominantly infects horses and sheep, causing a broad range of behavioural disorders. It is controversial whether BDV infects humans and causes psychiatric disorders. Objective: We searched for BDV-derived nucleic acids in blood of race horses and jockeys riding the horses. Methods: We assayed for the BDV genome in RNA extracted from peripheral blood mononuclear cells (PBMC) of 39 race horses and 48 jockeys. Two polymerase chain reaction protocols [one-tube reverse transcription-polymerase chain reaction (RT-PCR) and two-step RT-PCR] were used to assay BDV p24 and p...
Findley JA, Singer ER, Milner PI, Leeming GH.Soft tissue sarcomas of the equine distal limb associated with joints, sheaths, or bursae have rarely been reported. Accurate diagnosis of these tumors is challenging in both human beings and veterinary species. Immunohistochemical staining and transmission electron microscopy have been used in human beings to reduce misdiagnosis. The current report describes 2 mature horses presenting with lameness and swelling associated with the dorsal aspect of the metacarpo(tarso)phalangeal joint. In both cases, surgical excision was performed with subsequent histological analysis of the masses to determi...