Experimental fascioliasis in the rabbit

Urquhart, George MacDonald (1956) Experimental fascioliasis in the rabbit. PhD thesis, University of Glasgow.

Abstract

This thesis describes some aspects of the experimental infection of rabbits with Fasciola hepatica. The first part is concerned with the value of the rabbit as host in experimental fascioliasis. To this end, some experiments were carried out to determine the importance of some of the factors which might influence the number of adult flukes developing in a rabbit from a given number of cercariae. It was concluded that two of the most important factors are the technique of infection and the natural resistance of the rabbit. Details are given of a simple, rapid and efficient technique of infection and it was concluded that the natural resistance of the rabbit to infection with P. hepatica was about the same level and within the same limits as that of the sheep. The work described in the second part of the thesis is concerned with the anaemia associated with fascioliasis. This was shown to be macrocytic and hypochromic and accompanied by a constant reticulocytosis; the plasma contained no excess bilirubin or biliverdin and the spleen was always deficient in iron. The marrow was hyperplastic and normoblastic. Blood or blood products were consistently demonstrated in the common bile ducts of infected rabbits and in the caeca of the flukes. The anaemia disappeared when the flukes were removed by an anthelmintic. It was concluded that the anaemia was repeated bleeding, i.e., that the anaemia was post-haemorrhagic in type. Attempts were made to estimate the blood losses produced by the adult flukes in the bile ducts by radioactive Isotope techniques in which red cells and plasma were labelled with and respectively, and injected into infected rabbits. These were killed and the amount of blood in the flukes calculated by measuring their radioactivity. It v/as concluded that each fluke removes 0.25 ml, daily. A further section describes the results obtained by the immunisation of rabbits, with proteins of P. hepatica. This was shown to stimulate, the production of precipitins in relatively large amounts as measured by quantitative precipitin tests. Immunisation of rabbits with these proteins prior to infection was shown to produce inhibition of development of the parasites, but did not reduce their numbers significantly. In the last section of the thesis, the serial pathology of experimental fascioliasis is described in rabbits. These lesions are discussed and it is concluded that the cirrhosis characteristic of fascioliasis is due to:- (a) the healing of the tracts and infarcts produced by the migrating flukes; (b) chronic cholangitis caused by the presence of the adults in the large bile ducts; (c) hyperplasia of both connective tissue and biliary elements in the portal tracts; (d) granulomatous lesions formed in response to the presence of fluke eggs in the tissues.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: J W Emslie
• Keywords: Veterinary science
• Date of Award: 1956
• Depositing User: Enlighten Team
• Unique ID: glathesis:1956-73257
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73257