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.
Jaeschke G, Rudolph R.Clinicopathological aspects of equine leukosis are discussed in a review. Among various other findings, only hypercalcaemia accompanied by paraneoplastic syndrome in the course of equine leukosis, increased values of alkaline phosphatase as usual in tumorous diseases, and hypalbuminaemia and hypergammaglobulinaemia in mesentric and intestinal forms of equine leukosis seem to have some diagnostic and pathogenetic significance. Changed values of further parameters are more or less non-specific concomitant signs, indicating that other organs or organ systems have been affected. However, in case o...
Legrottaglie R, Agrimi P.Electrophoretic analysis in polyacrylamide gel (PAGE) of the equine rotavirus 106/88/LI/EQ, isolated from the diarrhea of an 18 day old foal was compared to the bovine strain NCDV. There was a notable difference in the migration of some segments of the viral RNA. Bands 2 and 3 of the equine rotavirus comigrated while there was a clear separation of segments 7, 8 and 9. Moreover, the migration of segments 1, 4 and 5 revealed a lower molecular weight than the corresponding segments of NCDV.
Gunn HM, Fraher JP.The incidence of sarcocysts was examined in postural, propulsive and respiratory muscles from 74 horses ranging in age from mid-gestation to 14 years post-natal. Cryostat sections were stained for myosin adenosine triphosphatase (ATPase) at pH 9.5 and the type of muscle fibre containing sarcocysts was identified. Sarcocysts were found in muscles from three animals, all aged 1 year or more. Counts showed that they displayed no preference for any particular muscle. However, fibres with a high activity for myosin ATPase were preferentially colonized. Transverse sectional profiles of sarcocysts sh...
Divers TJ, Timoney JF, Lewis RM, Smith CA.A 12-year-old thoroughbred gelding died from diffuse global glomerulonephritis, 3 months after a lower respiratory infection from which Streptococcus zooepidemicus was isolated. Immunopathological studies (immunofluorescence, immunodiffusion, immunoperoxidase testing and immunoblotting) indicated the presence of an immune reactant renal disease associated with IgG antibody and streptococcal antigens.
Hoffman AM, Baird JD, Kloeze HJ, Rosendal S, Bell M.Mycoplasma felis was identified as the cause of acute pleuritis in 2 show-jumping horses. The pleural exudate was proteinaceous, contained large numbers of neutrophils, and had a markedly increased lactate concentration. M. felis was isolated in pure culture from pleural fluid. Rising serum antibody titers to M. felis as well as a precipitous decline in titers to equine influenza virus were demonstrated in both horses. Pleural effusion in both horses and a pneumothorax detected in one of the horses resolved following a single drainage of pleural fluid and intravenous fluid, antibiotic, and ana...
Wilkie DA.A silicone subdermal implant was used in the surgical repair of a superior palpebral defect in a horse. The right superior palpebra was missing from the lateral canthus superiorly to the 1 o'clock position, and a corneal ulcer, anterior uveitis, and right micropalpebral fissure also were observed. Lateral canthotomy and canthoplasty were performed to enlarge the palpebral fissure, and a silicone implant was inserted in the superior palpebra to replace the missing tarsal plate. These procedures resulted in a successful reconstruction, with improvement of palpebral function.
Oikawa M, Kaneko M, Yoshikawa T.To elucidate the pathomorphogenesis of extremely shortened small-intestinal villi, occurring spontaneously in neonatal foals, the morphology of the small intestine with stunted villi was studied in eight cases. All intestinal wall elements and the villi were poorly developed. Most villi were found to be extremely short throughout the entire length of the small intestine. The villous core consisted of undifferentiated, fibroblast-like cells held loosely together by ground substance which was rich in glycosaminoglycan. Development of the villous lamina propria was poor with respect to capillarie...
Kannegieter NJ, Ecke P.A Thoroughbred gelding was referred for treatment of a parotid duct fistula. This had developed after the referring veterinarian had excised a portion of the duct, and ligated the proximal end, as a means of treating a recurring sialocoele. This report describes the successful surgical reconstruction of the excised 15 cm portion of the parotid duct using an interposition polytetrafluoroethylene tube graft.
Proudman CJ.The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other implications and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significant...
Greet TR.The paper describes the outcome of 16 cases of short-ileal-ileal intussusception in young Thoroughbred horses. The intussusception was often associated with chronic or intermittent low grade abdominal pain. At laparotomy, only the intussusception was reduced in one horse; in another, a myotomy of the thickened stenosed intussusception was carried out after reduction. In 11 cases as ileocaecal bypass anastomosis was performed proximal to the intussusception after its reduction. One horse was subjected to euthanasia during operation because of irreversible intestinal wall damage and another beca...
Ojala M, Ala-Huikku J.From 1974 to 1979, seven stillborn foals with internal hydrocephalus were encountered from one Standardbred trotter stallion which sired 239 registered foals. An hydrocephalic foal was also aborted by a daughter of the same stallion. One affected foal from Standardbred trotters and one from a Finnish Horses were also reported. In some cases, the condition caused severe dystocia. Based on field data, possible causes of the defect could neither be proved nor specifically overruled in individual cases. Hydrocephalus was obviously not an autosomal recessive single-locus defect, nor was it X-linked...
Nakamura T, Kiryu K, Machida N, Iwata T, Oikawa M, Kaneko M.The common, external, and internal carotid and occipital arteries were examined histologically at the trifurcation of the common carotid arteries in 13 Thoroughbred foals (0 to 30 days old) and 64 Thoroughbred adults (2 to 4 years old). Calcification in the media of the common carotid and external carotid arteries was observed in 3 of the 13 foals and in 30 of the 64 adult horses. Calcification resembled that seen in Mönckeberg's arteriosclerosis in human beings, the cause of which is unknown.
Hinrichs K, Cochran SL, Schelling SH, Steckel RR.A granulosa-theca cell tumor was found in an ovary that had an ovulation fossa and normal ovarian tissue. The ovary was removed from a mare with a history of ovarian enlargement and behavioral changes. The affected ovary had a multicystic appearance on ultrasonographic examination performed before surgery, and an ovulation fossa was not palpable on examination per rectum. However, during surgery, the affected ovary was found to be within normal size limits, with an enlargement on 1 pole, and to contain an ovulation fossa. Atrophy of the infundibulum of the affected ovary helped to confirm the ...
Bochsler PN, Slauson DO, Neilsen NR.Neutrophil (PMN) contributions to the acute inflammatory process and host defense include generation of bioreactive oxygen metabolites and secretion of granule enzymes. We assessed equine PMN secretion using several PMN stimuli, singly and in combination with bacterial lipopolysaccharide (LPS). LPS avidly associated with equine PMN, as shown by strong PMN labeling with FITC-conjugated LPS. LPS alone (1 or 10 micrograms ml-1) was a weak stimulus for PMN superoxide anion (O2-) generation, but preincubation with LPS followed by phorbol ester (PMA, 10 ng ml-1) significantly augmented (P less than ...
Park DL, Rua SM, Mirocha CJ, Abd-Alla ES, Weng CY.Naturally contaminated corn implicated in an outbreak of equine leukoencephalomalacia (ELEM) in southeastern Arizona was analyzed for mutagenic potential using the Salmonella/microsome mutagenicity assay before and after treatment with the ammonia procedure. Crude acetonitrile: water (1 + 1) extracts of high-pressure/ambient temperature (HP/AT) ammonia decontaminated, HP/AT plus low pressure/high temperature (LP/HT), and non-ammoniated fumonisin contaminated corn were tested for mutagenic potentials. Relatively pure (approx. 90%) fumonisin B1 standard was also tested for comparison purposes. T...
Naylor JM, Robinson JA, Bertone J.The pedigrees of 17 horses with hyperkalemic paralysis were studied. All were first-, second-, or third-generation offspring of a common sire, 16 were registered Quarter Horses. Analysis indicated that it was unlikely that the concentration of hyperkalemic periodic paralysis in the offspring of this sire was attributable to chance. The familial nature of this condition should help veterinarians diagnostically. It also suggests that it is possible to reduce the incidence of this condition by breeding from non-affected lines of horses and reinforces the need for studies to determine whether the ...
Bauerfeind R, Wieler LH, Weiss R, Baljer G.From April 1990 through June 1991 clinical salmonellosis and asymptomatic faecal excretion of Salmonella spp. were seen in hospitalized horses at two veterinary hospitals. 76 Salmonella strains from hospitalized horses and 18 strains from horses without any clinical contact were characterized by serotyping and plasmid profile analysis. From April 1990 through January 1991 97.8% of the hospitalized horses were infected with strains of S. typhimurium var. Copenhagen, which were closely related according to their similar plasmid patterns. Other strains of S. typhimurium var. Copenhagen and seroty...
Schumacher J, Dean P, Welch B.Unilateral epistaxis in 2 horses was caused by inflammation of the distal portion of the lacrimal system. The origin of epistaxis was identified during physical examination by observing hemorrhage emanating from the nasal opening of the nasolacrimal duct. Dacryohemorrhea caused by bacterial infection was successfully treated with antibacterial drugs administered systemically and instilled into the lacrimal system.
Evans AG, Paradis MR, O'Callaghan M.Six horses with chronic obstructive pulmonary disease (COPD) and 8 horses with recurrent urticaria were skin tested with 67 extracts from 58 allergens, including pollens, epidermals, cultivated farm plants, dusts, molds, and insects. Reactions were evaluated 3 times over a 24-hour period immediately after the injections. Results were compared with those obtained from 11 clinically normal horses. All horses had positive skin test reactions. Significant differences was evident between horses with COPD and clinically normal horses for only 3.0% of the possible extract reactions, and between horse...
Thiel PG, Marasas WF, Sydenham EW, Shephard GS, Gelderblom WC.Contamination of corn with the fungus Fusarium moniliforme and its secondary metabolites, the fumonisins, has been associated with several human and animal diseases. This paper summarizes present knowledge and presents new data on the levels of fumonisins present in foods and feeds associated with these diseases as well as in commercial corn and corn-based products. The doses of fumonisins to which humans and animals consuming these products would be exposed are compared with those doses known to produce LEM in horses and hepatocarcinogenesis in rats. It is concluded that the known naturally o...
Raengsakulrach B, Staczek J.Equine cytomegalovirus (ECMV) contains a linear, double-stranded DNA genome composed of a 146-kbp unique region flanked by a pair of 18-kbp direct repeat (DR) sequences at the termini. Cycloheximide, actinomycin D, and phosphonoacetic acid were applied to infected cell cultures to divide viral transcription into immediate-early (IE), early, and late phases. Eight IE transcripts were identified and mapped to two regions (I and II) of the viral genome. Two of these IE RNAs (13.0 and 5.5 kb in size) were transcribed from region I, which is located within the DR regions; these IE genes are diploid...
Brumbaugh GW, Sumano López H, Hoyas Sepúlveda ML.Each horse with laminitis is presented to the veterinarian at a different stage in progression of the condition and with varying severity. The pathogenic timing is often unknown and is difficult to determine. Because timing and severity are related to both the lesion's severity and responsiveness to treatment, these factors are critical to treatment selection and success. It is erroneous to assume that each horse with laminitis should receive each treatment. It is therefore important to ascertain as logically and objectively as possible the pathophysiological stage of development of each horse...
Dixon JB, Allan D, West CR.The purpose of these investigations was to assemble and compare data which might illustrate a functional relationship between phytohaemagglutinin-induced transformation of equine lymphocytes in vitro and the haematological profiles of the lymphocyte donors. Statistically significant correlation between transformation and a haematological parameter was taken as evidence that both may be part of a common regulatory system. There was no evidence that transformation in vitro was affected by artefactual variation in the cellular composition of the cultures. Transformational behaviour of lymphocytes...
Raś A, Otrocka-Domagała I, Raś-Noryńska M.Genital malignant neoplasms in mares are relatively rare. The treatment involve surgical removal of the tumour masses, chemotherapy or both. Methods: Two elderly warmblood mares, aged 16 and 20 were presented in University Clinic with the lumpy lesions at the region of perineum and left labia. Surgical removals of tumour masses were performed on standing animals. Removed tissues were subjected to histopathological examination which confirmed SCC. Conclusions: Clinical and ultrasound examination of reproductive organs in both mares showed no inflammatory or neoplastic changes. Both mares healed...
Moore-Colyer M, Longland A, Harris P, Zeef L, Crosthwaite S.Soaking hay fodder to reduce dust and soluble carbohydrate (WSC) contents prior to feeding is common practice among horse owners. Soaking can increase bacteria load in hay but no information exists on how this process alters the bacteria profile, which could pose a health risk or digestive challenge, to horses by introducing foreign bacteria into the gastrointestinal tract and so altering the normal profile. The current objectives were to map the bacterial profile of 3 different hays and determine how soaking alters this with the aim of improving best practice when feeding stabled horses. A Pe...
Richet G.P. Rayer (1795-1867) had never thoroughly published his experimental studies on the contagion of glanders. His recently un-earthed hand written papers allow us to depict his experimental approach and its results. He was not the first who transmitted glanders from a patient to horses or donkeys. But he did it systematically with glander secretions from acute and chronic cases. Whatever was the disease of the donors the transmitted forms were unpredictably either chronic or acute. His conclusion was that the two forms were two symptomatic aspects of a unique disease. Clinically dormant states we...
Smith BP.Salmonellosis in horses may result in fever, anorexia, and depression without concurrent diarrhea or other obvious gastrointestinal abnormalities and should be considered in cases of fever of unknown origin. The syndrome also is characterized by neutropenia, usually with a left shift, and growth of small numbers of salmonella from feces cultured in selenite enrichment broth. Repeated culturing may be necessary to isolate the organism. All six affected horses of this report recovered in 3 to 7 days without specific therapy.
Borst GH, van der Weij PJ, Vos JH.Acute idiopathic gastric rupture resulted in sudden death of a 4.5-months-old healthy Friesian foal. No morphological lesions were present which could explain the preceding gastric impaction. In this case hypodypsia may have been (partially) responsible for the impaction as only a mechanical drinking apparatus, unsuitably for horses, was available.
Levine DG.The first weeks of life are critical in many aspects, and the musculoskeletal system is no exception. Being able to stand and nurse within hours of life is necessary for survival. Laxity, flexural deformities, and skeletal immaturity can all make it difficult for neonates to ambulate. The increased vascularity to bones and cartilage mixed with the newly forming immune system also make neonates susceptible to infections that we rarely see in adult animals. This article concentrates on orthopedic conditions seen in the first 2 weeks of life.
Berkowski W, Plummer CE, Ramos R, Czerwinski S, Brooks D, Gallagher A.A yearling Thoroughbred stallion and an 8-year-old Saddlebred mare were evaluated for persistent mucoid ocular discharge. Results: Examination of both horses revealed copious yellow-tan mucoid ocular discharge with a negative Jones I test, absent nasal punctum, and unsuccessful anterograde nasolacrimal duct (NLD) irrigation. Clinical abnormalities were present on the right side only in one horse and bilaterally in the other. Computed tomography (CT) with contrast confirmed nasolacrimal duct atresia in both horses. Results: Under general anesthesia, the affected NLD was catheterized anterograde...
Bristol DG.Enterocutaneous fistulae are rare in horses and occur most commonly as a complication of umbilical hernias or their treatment. Horses with enterocutaneous fistulae may be successfully treated by en bloc resection of the body wall and intestine or by allowing second intention healing. Complications associated with surgical intervention include fever, colic, incisional problems, and recurrence of the fistula. Nonsurgical management of two horses with presumptive large colon fistulae resulted in resolution of the fistulae without complications.
Böse R, Peymann B, Barbosa IP.Sera from 60 horses held in breeding herd in Brazil were examined monthly by ELISA, immunofluorescence antibody test (IFAT) and Western blot. All foals had maternal antibodies detectable by ELISA and IFAT, and sero-conversion took place between the 2nd and 5th month of age. The 48 and 50 kDa antigens were recognized first in the course of infection. Of 79 sera taken after sero-conversion 78 reacted with the 48 kDa antigen, 76 with the 50 kDa, 50 with the 70 kDa, 54 with the 112 kDa, 72 with the 141 kDa antigen. In general, sera from horses older than 1 year reacted with all 5 diagnostic antige...
Cahill JI, Goulden BE.Evidence for a central nervous system component of the distal axonopathy associated with equine laryngeal hemiplegia was found in this survey of 33 horses (control, 15; subclinical, 8; clinical, 10). Significantly higher numbers of axonal spheroids were present in sections of the lateral cuneate nuclei in layngeal hemiplegic horses than in those unaffected by the disease.
Mills PC, Ng JC, Auer DE.The effect of the acute-phase response (APR) on the activity of the hepatic drug-metabolizing system (DMS) and on the binding of phenylbutazone to plasma proteins was investigated in the horse. An APR was induced by intramuscular injections of Freund's complete adjuvant in five horses and, five days later, these horses together with five clinically normal horses were shot and the right ventral lobe of each liver removed. The hepatic microsomal fractions from the liver samples were isolated and significantly lower (p < 0.01) concentrations of cytochromes P450 and b5 and activities of aniline...
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.
Bueno I, Pearce P, Dunowska M. To estimate the frequency of infection with equine herpesvirus type-1 (EHV-1) among horses from the central North Island of New Zealand, including the frequency of detection of the D genotype. Samples of retropharyngeal lymph nodes (RLN) and submandibular lymph nodes (SLN) were dissected from the heads of 63 horses that were humanely killed for various unrelated reasons between March and November 2015. DNA extracted from these tissues was subjected to enrichment for EHV-1 sequences by hybridisation with biotin-labelled EHV-1 specific probe, followed by recovery of EHV-1 sequences on streptavi...
Fricker C, Riek W, Hugelshofer J.The digital arteries of 10 horses suffering from navicular disease, and 7 horses from a control group, were examined angiographically. The horses from the disease group showed complete or partial occlusion of the digital arteries in all cases. In the control group of 7 healthy horses, isolated vessel obstructions were also found but these were limited to narrowing of part of an artery only. Histological investigations showed that total occlusion of a vessel involved an organised thrombus but that partial occlusion generally involved changes to the vascular wall, similar to those caused by enda...