Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
Clayton HM, Duncan JL.Following infection with 8000 Parascaris equorum eggs in two- to four-week-old foals reared under worm-free conditions a high percentage of the infective dose completed its tissue migration and returned to the small intestine. Patent infections were establisehd between 81 and 104 days after infection and high faecal egg counts were recorded. A group of six- to 12-month-old foals, which had been either reared under worm-free conditions or exposed to natural ascarid and strongyle infections on pasture, received a similar infection of 8000 P equorum eggs. Compared with the younger foals there was...
Cummings JF, de Lahunta A, Timoney JF.Four cases of neuritis of the cauda equina (NCE) were studied by light and electron microscopy. Examination of sacral intradural rootlets revealed inflammatory cell infiltrates and an array of myelinated fiber changes which included myelin stripping by invading mononuclear cells and macrophages, as well as splitting and vesiculation of myelin lamellae without obvious participation by leukocytes. More distally in the extradural roots, there was marked granulomatous inflammation, and demyelinative changes were overshadowed by widespread evidence of irreversible axon damage. In all cases, unusual...
Buntain B, Greig WA, Thompson H.The clinical and pathological features of a case of chronic nephritis in a 17-year-old pony was described. Measurement of fluid intake and laboratory analysis of sequential blood and urine samples helped in establishing an accurate diagnosis. The case demonstrates that although chronic renal disease is not well documented in the horse it should nevertheless be considered in the differential diagnosis of conditions characterised by progressive loss of weight.
Buntain B, Greig WA, Thompson H.The clinical and pathological features of a case of chronic nephritis in a 17-year-old pony was described. Measurement of fluid intake and laboratory analysis of sequential blood and urine samples helped in establishing an accurate diagnosis. The case demonstrates that although chronic renal disease is not well documented in the horse it should nevertheless be considered in the differential diagnosis of conditions characterised by progressive loss of weight.
Cox JE, Edwards GB, Neal PA.The authors analyse data collected over 23 years from 500 cryptorchid horses. They show that left- and right-sided abdominal cases occur with approximately equal frequency in ponies. Approximately half the right-sided unilateral abdominal cases have the epididymal tail descended while only 20 per cent of the left-sided cases do. These findings are briefly discussed. From their analysis of inguinal cryptorchidism the authors conclude that it is a relatively more complex phenomenon with incidence changing with age as well as breed. Right-sided retention predominates in young ponies, probably bei...
Roberts MC.Two young ponies had the prescrotal portion of their penises accidentally amputated during castration. They both developed ascending urinary tract infections over the next 4 weeks. One pony had a necrotising cystitis and pyelonephritis, the other improved markedly after a urethrostomy had been performed but was destroyed several months later.
MacKay RJ, Urquhart KA.Eight mature horses which had been affected with a moist cough for six weeks were found to have large numbers of eosinophils in tracheal mucus samples taken by transtracheal washing. These horses were kept on irrigated pasture and fed a hay-free diet. A companion yearling donkey was found to be passing Dictyocaulus arnfieldi larvae in its faeces. Two oral treatments with a dose of thiabendazole (440 mg/kg) resulted in the resolution of the clinical signs and the disappearance of eosinophils from transtracheal washings. The eosinophilic bronchitis seen in these horses was presumed to be a manif...
Gunson DE.Despite being a very widespread protein, collagen is an unusual molecule possessing a great tensile strength conferred by a rope-like structure and intermolecular crosslinks. Our current knowledge of the biosynthesis of collagen is providing some insights into certain diseases of connective tissue and is also helping us to understand the healing processes of wounds and diseased tissues.
Blue MG.In a retrospective study of selected cases, abdominal colic in 30 horses was attributed to enterolith obstructions of the large intestine. Obstructions caused by "true" enteroliths were confined to horses more than four years old. Prominent clinical features were recurrent mild abdominal pain, inappetance, gaseous distension and minimal intestinal motility. The various aspects of the clinical syndrome, including diagnostic problems and clinical management, are discussed. Most obstructing enteroliths were found near the beginning of the small colon and most horses contained only a single major ...
Taylor CE, Rosenthal RO, Taylor-Robinson D.The presence of allugtinins to the causative organism of contagious equine metritis (C.E.M.) in human serum has been confirmed. Agglutinins were found in the serum of 84 (37.6%) of 223 patients with non-gonococcal urethritis (N.G.U.), and in 12.5% of these patients there was a four-fold or greater rise in titre during the course of their illness. There was no evidence that these agglutinins were the result of infection by chlamydiae or ureaplasmas. Certain patients with these agglutinins seemed to respond better to therapy with antibiotics to which the C.E.M. bacterium is susceptible in vitro ...
Slauson DO, Lewis RM.Glomerulonephritis constitutes an important category of renal diseases in animals and has been recognized with increasing frequency in the last decade. We report here the comparative morphologic aspects of glomerulonephritis as a naturally occurring disease of animals. We briefly review the immunopathogenesis of glomerulonephritis. The morphology of renal lesions occurring in glomerulonephritis in dogs, cats, cattle, sheep, horses and swine has been reviewed with emphasis on the range and specificity of various glomerular lesions and on the comparison of lesions between various species. A dist...
Colglazier ML.The efficacy of the benzimidazole, oxfendazole, and the organophosphate, caviphos, against gastrointestinal parasites of ponies was evaluated by the critcial test method. Oxfendazole (10 mg/kg of body weight) given in single oral doses was 100% effective against adult large strongylids (Strongylus vulgaris, Strongylus edentatus, and Strongylus equinus), 99% effective against adult small strongylids, and 97% effective against 4th-stage small strongylids (genera identified in order of frequency: Cylicostephanus, Cyathostomum, Cylicocyclus, Triodontophorus, Poteriostomum, Oesophagodontus, Cylicod...
Dietz WH, Peralta PH, Johnson KM.The clinical and laboratory findings in ten humans infected with Venezuelan equine encephalitis virus, subtype I-D, are described in this report. Clinical and laboratory data indicate that, in contrast to equine infections, human infection with these enzootic virus strains (I-D) is similar to human infection with epizootic strains (I-ABC). In most cases there was an abrupt onset of fever, muscle pain, and vomiting. Virus was recovered from sera obtained during the first 3 days of illness. Lymphopenia occurred in all patients, and neutropenia occurred in three. No sequelae of these infections w...
Hughes JP.Contagious Equine Metritis (CEM) is a highly contagious venereal disease of horses caused by a fastidious, Gram-negative coccobacillus which grows best on chocolate agar under microaerophilic conditions (5-10% CO2). Clinically, the disease is characterized by a copious watery-to-mucopurulent, vaginal discharge two to ten days after breeding by an infected stallion (11, 13). Shortened estrous cycle lengths are common and may be the only indication of endometritis in some instances (7). Inapparent carriers of the disease in both the mare and stallion make control of the disease more difficult. O...
McColl HP, Orchard VA.Sir,—A series of happy coincidences (serendipity?) has led us to a simple treatment which seems to have successfully alleviated symptoms of “rye-grass staggers” in a horse, a calf and two badly affected sheep. Although primarily engaged in a search for the causative agent(s) of rye-grass staggers, casual conversations with people having long experience of this disorder revealed many interesting observations. One of these was a racing-stable remedy for rye-grass staggers, which was the administration of “a couple of handfulls” of Epsom salts in a bran mash, with as much puha (Sonchus ...
Milne EM, Pemberton AD, Dixon PM, McGorum BC, Scudamore CL, Miller HR.The alpha 1-proteinase inhibitors of trypsin, Spi1, Spi3A, and Spi3B, in bronchoalveolar lavage fluid (BALF) and serum of horses were separated by electrophoresis, and their proportions were quantified in 12 control horses and 12 with chronic obstructive pulmonary disease (COPD). A significantly lower proportion of Spi3B (P < 0.05) and higher proportion of Spi1 (P < 0.02 to P < 0.01) were detected in BALF, compared with serum, in control and COPD-affected horses and appeared to be attributable to reduced Spi3 activity in BALF. There was no significant difference between the control an...
Kafarnik C, Donaldson D, Payne R, Holloway A.A 13-year-old cob mare was presented with exophthalmos and periocular swelling of the left eye. The diagnostic work-up included ocular ultrasound, sonographic examination through the thinned frontal bone, radiography, standing computed tomography of the skull and exploratory osteoplastic surgery. Histopathology was consistent with an organized hematoma. An intradiploic hematoma of the frontal bone was diagnosed 5 years after head trauma, with progressive expansion and deformation of the skull resulting in exophthalmos. Exophthalmos with facial bone deformation was the only clinical finding of ...
Norman TE, Chaffin MK, Perris EE, Edwards JF, David JB, Cohen ND, Reuss S.This report involves 6 cases in which medical records and post mortem findings were reviewed leading to the diagnosis of massive pulmonary thromboembolism (MPTE). All horses were mature and MPTE has not been recognised previously as a sequel to generalised systemic illness in mature horses. The clinical data and pathological findings of the cases are reported and the authors conclude that MPTE is an uncommon but important complication of medical and surgical disorders in mature horses. In 3 of the cases, the condition was nonfatal suggesting that some horses having developed PTE survive and th...