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.
White KK.Angular limb deformities in 3 foals were found to originate in the diaphyseal region of the 3rd metacarpal (2) and metatarsal (1) bones. In each case, treatment consisted of wedge ostectomy followed by compression plating. Two foals survived for useful performance; the 3rd was euthanatized because of ischemia of the operated limb. The condition appeared to resemble a similar syndrome in man involving tibial curvature.
Richardson DW, Kohn CW.The case records of 22 foals with uroperitoneum were reviewed. The most common cause was a defect in the urinary bladder. A sex predilection for males was apparent. Clinical signs were tachycardia, tachypnea, and abdominal distention. The history pertaining to micturition was variable. Hyponatremia, hypochloremia, and hyperkalemia were marked. A reliable means of diagnosis was considered to be the demonstration of a wide disparity in serum and peritoneal fluid creatinine values. Surgical repair was successful in 11 of 18 cases, although surgical and anesthetic complications were common. Some o...
Ribbeck R, Heide H, Schicht W, Hiepe T.Observations were carried out from May 1977 to May 1980 on occurrence, fauna, and seasonal dynamics of Gasterophilus spp. in 2,539 horses for butchering from all districts of the German Democratic Republic and also in 79 horses after control against gasterophilosis. 99.98% of the 13,742 second and third instar larvae of horses for butchering were Gasterophilus intestinalis, only 0.02% Gasterophilus nasalis. Out of 7,765 larvae passed after control measures Gasterophilus intestinalis dominated with more than 96%. Only in four districts of the German Democratic Republic Gasterophilus nasalis was...
Turk MA, Breeze RG, Gallina AM.The pathologic features of bronchiolitis were studied in horses and ponies from 30 minutes to 27 days after an oral dose of 3-methylindole (3MI). From 30 minutes to 3 hours, lesions were limited to nonciliated bronchiolar epithelial (Clara) cells, which lost apical caps and cytoplasmic granules and had dilated smooth endoplasmic reticulum (SER). At 12 hours, necrotic Clara cells were exfoliated; degeneration and necrosis were evident, in bronchiolar ciliated cells. Rare epithelial cells with hyperplastic SER appeared on the denuded basal lamina at 24 hours. Inflammatory cells, epithelia, fibro...
Wiebe ME, Scherer WF, Peick WJ.Ninety-four strains of Venezuelan encephalitis (VE) virus isolated from sentinel hamsters exposed in the Middle American countries of Mexico, Guatemala, Belize, and Honduras were examined for the presence of virions with marker characteristics of strains that cause large epidemics and equine epizootics. Thirty-four strains came from before and 60 strains came from after the Middle American epidemics and equine epizootics of 1966 and 1969-1972. Twenty-three virion clones that resembled epizootic strains by hydroxylapatite chromatography and Vero monkey kidney cell plaque size determinations wer...
Miller RI.Although 'phycomycosis' is a common disease of horses in northern Australia little is known about the causative fungi. In this paper the laboratory methods for diagnosis are described. These revealed 38 cases caused by Pythium sp. (Hyphomyces destruens), 6 cases caused by Basidiobolus haptosporus and 2 caused by Conidiobolus coronatus. Laboratory studies on the chemotatic behaviour of zoospores of Pythium sp. showed that they were strongly attracted to both animal hairs and plant tissue. Because of this behaviour a simple baiting method using human hair was used to trap the fungus from water s...
van Wuijckhuise-Sjouke LA.Report on the case of a pony with colic submitted a to the department of internal medicine. However, the animal was found to be affected with dilatation of the oesophagus which had given rise to acute pleurisy resulting from rupture of the wall of the oesophagus. The diagnosis was established after death.
Brownlow MA.Cells in the peritoneal fluid from 179 horses were examined in Giemsa stained preparations using light microscopy. Neutrophils were found in all samples whether transudative or exudative although their proportions varied enormously. They were well preserved in "normal" or sterile effusions and hardly differed morphologically from those seen on a peripheral blood film although hypersegmentation was commonly observed. In purulent effusions a reliable correlation was found between degenerative changes in neutrophils such as karyolysis and karyorrhexsis and the presence of toxin-producing microorg...
Morris DD, Whitlock RH.TEIROMBOCYTOPENIA can be caused by failure of production or increased destruction of platelets, resulting in a bleeding diathesis, characterised by mucosal petechiac and haemorrhage into various organs. In humans, some drugs (cg, phenylbutazone and chloramphenicol) cause idiosyncratic marrow suppression and subsequent thrombocytopenia. Bone marrow suppression is also well documented in humans and small animals receiving cytotoxic drugs (Calabresi 1979; MacEwen 1980). Decreased megakaryocytic proliferation is rarely recognised in large animals. The most prevalent causes of thrombocytopenia are ...
Okladnikov GI.The main clinical varieties of spinal cord and equine tail tumors are reviewed. Of 221 cases, the progressive course of the disease was recorded in 76,9%, slow-progressive course was observed in 68,1% and rapid-progressive in 8,8% of cases. It is stressed that in the presence of the progressive course of the disease there may occur different manifestations of the tumorous process of the spinal cord, the examination of which makes it possible to improve the diagnosis, particularly in the early stage of the spinal oncological process.
Lees MJ, Kleider N, Tuddenham TJ.Five horses were presented because of a dermatitis of the forehead. Unlike previous reports, ventral midline dermatitis was not the major problem, and was present in only two of five cases. All five horses responded to levamisole therapy at a daily dosage of 5.5 g for one week. Owners were cautioned that repeat therapy may be necessary.
Magnuson NS, Decker DM, Perryman LE.1. Activities of S-adenosylhomocysteine (AdoHcy) hydrolase were measured in tissues of horses with severe combined immunodeficiency. No decrease in activity of the enzyme was detected.
2. The activity in erythrocytes was 14.2 ± 9.2 nmol AdoHcy formed/min/g hemoglobin and in fibroblasts it was 28.0 ± 7.9 nmol AdoHcy formed/min/108 cells.
3. Km values were obtained for hemolysates (0.77 μM) and for fibroblast lysates (0.59 μM).
4. Effects of 2′-deoxyadenosine on enzyme inactivation were studied.
Nakazawa M, Sugimoto C, Isayama Y.The selective isolation of R. equi in NANC medium was made by quantitative culture of the organism in the feces. R. equi was observed in the feces of all the mares and foals investigated. The mean viable count of R. equi organisms in 1 gram of feces was 8.42 X 10(2) in the mares and 7.57 X 10(2) in the foals, and its 95% confidence limits were in a range of 6.48 X 10(2) to 1.09 X 10(3) and 4.19 X 10(2) to 1.37 X 10(3), respectively. This result indicates that R. equi is a member of the normal intestinal flora in the horse.
Bistner S, Campbell RJ, Shaw D, Leininger JR, Ghobrial HK.A nine-year-old horse was presented with severe exophthalmos of the right eye and a large mass in the vitreal cavity. The affected globe was enucleated and two months following surgery the horse was euthanized because of spread of the tumor into the calvarium producing compression of the brain stem and neurologic signs. Examination of tumor tissue by light and electron microscopic examination showed a mixed neoplasm of primitive neuroepithelium.
Mäkinen A, Katila T, Kuokkanen MT.Only one X chromosome was found in each of the lymphocyte metaphases studied in an infertile mare. Karyotype analysis was made with the CBG and GTG banding techniques. The most obvious clinical abnormality was gonadal hypoplasia.
Malalana F, Ireland JL, Pinchbeck GL, McGowan CM.Risk factors for a first episode of primary uveitis in horses have not been determined. In addition, disease progression and the proportion of horses that develop recurrence following the original episode are not known. Objective: To determine the risk factors for the development of a first episode of primary uveitis in horses in the UK and to document the proportion of cases that experience recurrence following this first episode. Methods: Prospective case-control longitudinal study. Methods: Horses with a first episode of primary uveitis between July 2014 and August 2018 were recruited to th...