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.
Parker GA, Novilla NM, Brown AC, Flor WJ, Stedham MA.A granular cell tumour (myoblastoma) occurred in the lung of an aged mare. Multiple greyish-white neoplastic nodules of various sizes almost replaced one lung. Histologically, the neoplasm consisted of small clumps of granular cells in a stroma composed of thick bands of collagen and numerous capillaries. The globoid or stellate neoplastic cells were characterized by a large number of eosinophilic, PAS-positive, diastase-resistant cytoplasmic granules. Ultrastructurally, the granules were of two types: (a) homogeneous, electron-dense granules and (b) multimorphous granules that resembled cell ...
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.
Ribeiro HS, Larangeira NL, Paiva F.The authors sacrificed fifty-five horses originated from the "Pantanal", lowlands in the State of Mato Grosso in two different periods, droughty period and flooded and they described for the first time the Dictyocaulus arnfieldi in Mato Grosso. Relationship between droughty and flooded periods proved not to occur.
Sahu SP, Dardiri AH, Rommel FA, Pierson RE.Survival of bacteria that cause contagious equine metritis (CEM) was evaluated in Amies modified transport (AMT) medium, in AMT medium with charcoal, and in Stuart transport medium at 37, 22, 4, and -70 C. The CEM bacteria suspended in transport media survived at 22, 4, and -70 C for longer periods in AMT medium with charcoal than they did in AMT and Stuart transport media. In 1 day, the number of bacteria in exudate stored in the absence of any transport medium decreased 15-fold at 22 C and twofold at 4 C. The CEM bacteria were isolated from exudate on cotton-tipped swabs from all three trans...
Smith HJ.From 1967--1978 observations were made on the presence of the small equine pinworm, Probstmayria vivipara, in seven experimental ponies. The life cycle of this nematode is unusual in that it is endogenous with development of all stages occurring within the host's digestive tract. Initially, worms were found in the feces of four of seven ponies following treatment with thiabendazole but the infection was later transmitted to all ponies possibly via coprophagy. Still later, based on fecal and postmortem examinations, four of the seven ponies lost their pinworm burdens. At necropsy, the principal...
Owen R, Fullerton JN, Tizard IR, Lumsden JH, Barnum DA.Clinical, bacteriological, serological and haematological observations were made on 13 adult ponies orally inoculated with Salmonella typhimurium. The results were compared to two control ponies and four others infected by accidental transmission. The clinical responses in inoculated ponies included pyrexia lasting four days and neutropaenia during the first five days after inoculation followed by a neutrophilia. Pyrexia and neutropaenia was associated with maximal shedding of organisms in the rectal faeces. Changes in the character of the faeces occurred between one and two days after inocula...
Matthews AG.Three major antiprotease components in equine serum were identified and characterised. These were the acidic prealbumin Pr, the homologue of human alpha-1 antitrypsin and 2 protease binding proteins, the acidic prealbumin Xc and alpha-2 macroglobulin, both capable of inhibiting the proteolytic activity of trypsin, but with only limited inhibitory effect on its esterolytic activity. The possible role of these serum antiproteases in the onset of chronic obstructive pulmonary disease (COPD), analogous to the hereditary dysproteinaemia of alpha-1 antitrypsin in man, was investigated. There was no ...
McPherson EA, Lawson GH, Murphy JR, Nicholson JM, Breeze RG, Pirie HM.Breed, age, weight, type of work performed, seasonal onset, poor ventilation and exposure to moulds in the habitat were investigated in relation to the occurrence of chronic obstructive pulmonary disease (COPD). COPD was most commonly detected in showjumping and hacking horses. The older a horse, the more likely it was to become affected although most were 6 to 10 years of age. Of the horses in this sample of the population, which was not a random one, thoroughbred horses were affected least and ponies most often. The high incidence in ponies was related to their more frequent exposure to poor...
McPherson EA, Lawson GH, Murphy JR, Nicholson JM, Breeze RG, Pirie HM.Micropolyspora faeni and Aspergillus fumigatus were identified as common causes of respiratory hypersensitivity in horses affected with chronic obstructive pulmonary disease (COPD). Rye grass pollen and an Actinomycete evoked respiratory allergy in a few horses. Not infrequently, individual horses were found to have respiratory hypersensitivity to two or more antigens. The methods used to examine for allergy were intradermal testing and inhalation challenge with environmental antigens. An intradermal test using an M faeni extract was demonstrated to be suitable for diagnostic use in horses pre...
English AW.The anterior mesenteric arteries of 138 horses slaughtered in southern Queensland were examined for the presence of S. vulgaris larvae. Seasonal differences were noted in the size of arterial populations of this parasite, with higher mean monthly numbers of worms per horse occurring in winter. There was an equally high incidence of severe verminous arteritis during the winter months of June, July and August, compared to arteries examined during the warmer months, when there were smaller numbers of larvae. It was concluded that more infective larvae were available on pasture during the warmer m...
McDonald TL, Burger D.Initial separation and concentration of Clq from fresh, normal equine serum was accomplished by precipitation in 0.02 M acetate buffer, pH 5.5, at 4 degrees for 24 h. The re-dissolved precipitate was clarified by centrifugation at 80,000 g for 1 h and then dialysed against Tris-HCl buffer (0.05 M, pH 8.0) containing 10-3 M EDTA. The clarified dialysate remained biologically active at 5 degrees for at least 4 weeks. Biological activity of equine Clq was determined by assay of its ability to agglutinate sensitized sheep erythrocytes (EA). Following ammonium sulphate fractionation, Sepharose 4B g...
Scott EA, McDole M, Shires MH.Sixty-five cases of third phalanx (P3) fracture were retrieved from 20,638 case records at Michigan State University's Veterinary Clinical Center between Feb 1, 1964 and July 1, 1977. The fractures were classified by anatomic location, using a numbering system. Data from case records indicated the most common P3 fracture involved the articular surface of the coffin joint (53 of 65 cases; 81.5%). The greatest occurrence of P3 fracture was in Standardbreds (31 of 65 cases). Thirty-three of the 65 fractures were in geldings of all breeds; 57 of the cases were distributed among racing horses of fo...
Kotzé SH.The arteries supplying the ileocaecal junctions of 7 horses were injected with latex via the A. ileocolica and dissected macroscopically. The same basic pattern emerged whereby a single papillary artery arising from the R. ilei mesenterialis, supplied all aspects of the ileocaecal papilla. In one instance, the papillary artery arose directly from the ileocolic artery. No collateral arterial supply to the ileocaecal junction was present in any of the specimens dissected.
Thompson DB, Spradborw PB, Studdert M.Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.
Baker E, Geick A, Hines M, Gerhold R, Cordero-Aponte C.A 17-year-old female grade pony presented to University of Tennessee Veterinary Medical Center in May of 2021 for evaluation of multifocal, firm, sessile, circular lesions of various diameters on the ventrum and flank. The lesions had been present for two weeks at presentation. An excisional biopsy found numerous adult and larval rhabditid nematodes most consistent with Halicephalobus gingivalis. PCR targeting a portion of the large ribosomal subunit confirmed this diagnosis. The patient was treated with a high dose course of ivermectin followed by fenbendazole. The patient began showing neuro...
Crucière C, Guillemin MC, Roseto A, Wirbel A, Plateau E.Monoclonal antibodies (Mo Abs) were prepared against influenza/A/equine/Prague/1/56 (H7N7) and influenza/A/equine/Miami/1/63 (H3N8) reference strains of equine influenza virus. These monoclonals were tested against the 2 reference strains, 8 field strains of equine influenza virus, 3 human influenza viruses possessing the H3 hemagglutinin, and one virus of human origin possessing the H1 hemagglutinin. Two antibodies were obtained in one fusion against the Prague/1/56 strain and reacted only with this strain. Four anti/A/equine/Miami/1/63 Mo Abs were obtained in one fusion. They differentiated ...
Akinboade OA, Awani O, Best O, Cole T.Summary Twelve (12) heavy horses of the Shire breed imported into Nigeria in 1974 died within two months after importation. This was because of inclement weather and non-availability of AHS vaccine.
Gomez-Villamandos R, Santisteban J, Ruiz I, Avila I.Two horses with fibrotic myopathy of the semitendinosus muscle are described. The report deals with the aetiology, clinical signs and diagnosis of the condition, and discusses the different surgical techniques described in the literature. Tenotomies were performed on both horses. Excellent results were obtained in the horse in which only the semitendinosus muscle was affected, but in the horse in which the semimembranosus and gracilis muscles were also involved the results were less satisfactory.
Romanowska D, Szynkiewicz Z, Rita J.Antistreptolysin O (ASO) titers were determined in the sera of 532 horses from stud farms and 436 working horses from small farms. A statistically significant correlation was seen between the ASO titer and the age of the horses. There was a significant difference between mean ASO titer in horses 0-2 years and horses 2-10 years In horses older than 10 years the titer was significantly higher than mean ASO titer for the group. Twenty four of 30 horses in which ASO titer was higher or equal to 80 I.U. had histories which suggested that streptococcal infection had occurred. Clinical and bacteriolo...