Studies on bovine besnoitiosis with special reference to the aetiology

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dc.contributor.author Pols, J.W.
dc.contributor.editor Alexander, R.A.
dc.contributor.editor Clark, R.
dc.contributor.editor Louw, J.G.
dc.contributor.editor De Kock, V.E.
dc.date.accessioned 2016-09-30T15:36:41Z
dc.date.available 2016-09-30T15:36:41Z
dc.date.created 2016
dc.date.issued 1960
dc.description The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format. en_ZA
dc.description.abstract (1) A brief historical review of bovine besnoitiosis is given. (2) The importance of the disease as a veterinary and economic problem is stressed. (3) The identification of the causal agent, Besnoitia besnoiti (Marotel, 1913), has made it possible to give a concise definition of the disease. (4) The synonyms of bovine besnoitiosis are listed. (5) The distribution of bovine and equine besnoitiosis in Europe and Africa, and the occurrence of murine besnoitiosis in the United States of America are recorded. (6) A detailed account of the aetiology, based on observations made on rabbits and cattle, is offered. (7) Systematic studies on the development of the parasite cyst revealed that the cyst wall is of somatic origin. (8) The inner and intermediate membranes of the wall are derived from the markedly hypertrophied polynucleated host cell, the histiocyte, while the outer wall is formed by collagenous fibres. (9) The term pseudocyst, as applied by Jacobs (1956) for the Toxoplasma cyst where the cyst wall is also of somatic origin, should be used in the same sense for the Besnoitia cyst. (10) Certain chemical components of the parasite and cystic wall have been determined by histochemical tissue reactions. (11) Asexual reproduction by longitudinal binary fission within either monocytes or histiocytes is the only form of multiplication in the vertebrate host. (12) The "Fuls" B. besnoiti strain has been maintained by serial passage in rabbits for 125 generations. A gradual decrease in virulence of the parasite was noticed as the passage level increased. (13) B. besnoiti remains viable in citrated blood for 48 hours at 20°C, and for 96 hours at + 4° C. (14) A detailed survey of the complicated history of the nomenclature of certain Protozoa included in the genera Balbiania, Besnoitia, Eimeria, Fibrocystis, Gastrocystis, Globidium, Haplogastrocystis, Ileocystis, Lymphocystis, Sarcocystis and Toxoplasma is given. (15) Evidence has been brought forward that Besnoitia is a valid genus, that it is related to the genera Fibrocystis and Toxoplasma, but distinct from any of the remaining genera. (J 6) Absence of any characteristic features does not permit placing the genera Toxoplasma, Besnoitia and Fibrocystis in any natural scheme of classification in the Protozoa, and hence it is proposed to group them as "Parasites of Doubtful Nature". (17) It has been determined that, besides cattle and rabbits, sheep, goats and guinea pigs are susceptible, while two horses, a dog and several mice, rats, fowls and dassies failed to develop a microscopic infection and clinical symptoms after artificial infection. (18) The pathogenesis is discussed. (19) The natural mode of transmission is obscure. (20) Information on the epizootology is limited. (21) The symptomatology of bovine besnoitiosis in cattle, sheep, goats, rabbits and guinea pigs is described. (22) Bulls that survive a natural infection develop either a temporary or permanent sterility. (23) A temporary sterility, as determined by systematic microscopic semen examination of artificially infected animals, persisted for approximately six months in two bulls, for about three months in a billy goat, and four months in a ram. (24) Methods for making a diagnosis are described. In inapparent or atypical infections in male ruminants, aspermatogenesis can be used as a guide for making a diagnosis. (25) Investigations on bovine besnoitiosis have not advanced far enough to evolve reliable prophylactic measures. (26) Animals that survive either a natural or an artificial infection develop a durable premunity. (27) Photographs showing the course of the disease in a bull, the pronounced sclerodermatitis in a chronically affected animal, the development of a parasitic cyst in a bull and a rabbit, and the morphology and method of reproduction of B. besnoiti are presented. en_ZA
dc.identifier.citation Pols, JW 1960, 'Studies on bovine besnoitiosis with special reference to the aetiology', Onderstepoort Journal of Veterinary Research, vol. 28, pp. 265-356. en_ZA
dc.identifier.issn 0330-2465
dc.identifier.uri http://hdl.handle.net/2263/57071
dc.language.iso en en_ZA
dc.publisher Pretoria : The Government Printer en_ZA
dc.rights © 1960 ARC - Onderstepoort and Faculty of Veterinary Science, University of Pretoria (original). © 2016 University of Pretoria. Dept. of Library Services (digital). en_ZA
dc.subject Thesis en_ZA
dc.subject.lcsh Veterinary medicine -- South Africa
dc.subject.lcsh Besnoitiosis en_ZA
dc.subject.lcsh Cattle -- Diseases en_ZA
dc.subject.lcsh Diseases -- Causes and theories of causation en_ZA
dc.title Studies on bovine besnoitiosis with special reference to the aetiology en_ZA
dc.type Article en_ZA


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