1960 Onderstepoort Journal of Veterinary Research, Volume 28, Number 3, 1960

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Contentes Pages: Onderstepoort Journal of Veterinary Research, Vol ??, 19??

CONTENTS

*Volume 28: Number 3*

Studies on bovine besnoitiosis with special reference to the aetiology	Pols, JW	265

A preliminary antigenic classification of strains of bluetongue virus	Howell, PG	357

A field study of some nematode parasites of bovines in a semi-arid area, with special reference to their biology and possible methods of prophylaxis	Reinecke, RK	365

Trichuris species from South African rodents and a hyracoid	Verster, A	465

Capillaria hepatica infestation in a dog	Smit, JD	473

Blood groups in bovines. I. Production of cattle iso-immune sera and blood group reagents	Osterhoff, DR	479

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A field study of some nematode parasites of bovines in a semi-arid area, with special reference to their biology and possible methods of prophylaxis
(Pretoria : The Government Printer, 1960) Reinecke, R.K.; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
Preliminary field investigations revealed the presence of Cooperia pectinata, C. punctata, Haemonchus placei, Oesophagostomum radiatum and Bunostomum phlebotomum as the most common parasites of bovines in the North Western Cape. Experiments on the ecology and epizootology of these parasites were carried out under field conditions, at the Armoedsvlakte Research Station near Vryburg in the North Western Cape. Possible methods of prophylaxis based on experimental observations are described, and the possible use of strategic drenching, using anthelminthics which gave promising results, is included.
Blood groups in bovines. I. Production of cattle iso-immune sera and blood group reagents
(Pretoria : The Government Printer, 1960) Osterhoff, D.R.; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
A short introduction is given to the field of bovine blood group research. Some of the immunological terms used in immuno-genetics are explained. The genetic aspects are briefly dealt with. The methods used for the production of iso-immune sera are described. An analysis is made of the different sources of genetical and environmental variation in antibody production, and from this it is concluded that it is impossible to give detailed directives for their production. The difficulties of testing sera under high temperature conditions are dealt with. It is concluded that these difficulties can be overcome in South Africa only by carrying out all blood group work in an air conditioned laboratory. The fractionation of different antisera is presented in Table No. 6. As a result of basic investigations in South Africa, three new types of antibodies have been isolated in Afrikaner cattle, which react with three so far unknown antigenic blood factors. Only a few test sera could not be produced. Through international cooperation between blood group laboratories and particularly through exchanges of test sera, the South African laboratory was able to start routine blood group determinations. for different practical purposes and genetical studies, in 1958.
Capillaria hepatica infestation in a dog
(Pretoria : The Government Printer, 1960) Smit, J.D.; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
A review of the literature on Capillaria hepatica infestation is given. The first case of Capillaria hepatica in the dog in South Africa is described. The main gross and histopathological changes are described . The relationship between the Capillaria infection and the vascular changes are discussed. The opinion is expressed that the disintegrating worms were responsible for an allergic state in the body, leading to generalised calcification of the intima of the blood vessels.
Trichuris species from South African rodents and a hyracoid
(Pretoria : The Government Printer, 1960) Verster, Anna; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
1. Trichuris vondwei Ortlepp, 1938, and Trichuris parvispicularis Clapham, 1943, are considered to be synonymous. 2. Three new species of Trichuris are described: T. mastomysi from Mastomys natalensis; T. pedetei from Pedestes cafer; T. procaviae from Procavia capensis.
A preliminary antigenic classification of strains of bluetongue virus
(Pretoria : The Government Printer, 1960) Howell, P.G.; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
As a preliminary investigation the existence of 12 distinct antigenic types of bluetongue virus was established. Where the facilities are available, the methods employed provide a rapid and accurate procedure for the antigenic identification of field specimens.
Studies on bovine besnoitiosis with special reference to the aetiology
(Pretoria : The Government Printer, 1960) Pols, J.W.; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
(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.

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