The pathology and immunology of some parasitic infestations in domestic animals

Sharp, Norman C. Craig (1966) The pathology and immunology of some parasitic infestations in domestic animals. PhD thesis, University of Glasgow.

Abstract

This thesis describes the development, from the early laboratory-test stage, of the first vaccine to be successfully used on a wide scale against a parasitic helminth. The process utilises X-irradiation to attenuate the infective larvae. The work is presented in four parts, followed by technical, bibliographical and tabular appendices. The first part ie a discussion on both parasitic immunity and the application of X-irradiation to holminths. The second part describes experiments designed to test a vaccine against Dityoeaulus viviparus. The third part is a quantitative and qualitative study of D. viviparus larvae under the respective effects of X-irradiation, antibody and diethyl-carbamazine. The fourth part concerns the testing of a vaccine against Haetaonchus contorfcus. Part I contains a general introduction to parasitic immunity, with a brief indication of the importance of parasitism in both animals and man. this is followed by a description of: (a) previous attempts by other workers to vaccinate against helminth diseases; (b) the background of work behind the present method of vaccination. Part I ends with a review of various applications of X-irradiation to helminths. Part II is introduced by a small experiment designed to test the longevity of both first and third stage larvae of D. viviparus under a wide range of laboratory conditions. A short description of the parasite is included. Then follow the four experiments which form the bulk of this part. These were designed to test the effectiveness of the D. viviparus vaccine in various combinations of dose against a challenge apectrum ranging from a large single dose of infective larvae to a natural famsapasture challenge. Approximately 1,250 calves were involved in these expariments. Part III is mainly concerned with histo-pathological and quantitative assess-monts on the distribution and fate of irradiated larvae in the normal host and of normal larvae in the immune host. This work was done to study the made of action of, and the hoist-reaction to, the vaccine against D. viviparous in calves. It was known that a dose of irradiated larvae did not: produce a population of adult worms in the bronchi, and this experiment showed whore the larvae wore ceasing to develop. The pathological basis of the transient clinical signs sometimes seen after vaccination is described, as well as the correlation of lesions and clinical signs observed in the immune animal under heavy challenge. The last experiment in this part is a histopathological study of the pulmonary lesions produced by treating calves, in the prepatent or patent stage of parasitic bronchitis, with diethylcarbamazine. This drug inactivates or kills the parasite, and the host-reaction to the drug-disabled worn is interestingly similar to the reactions of the normal calf lung to irradiated larvae and of the immune-calf lung to normal larvae, The lesions in the calves treated at patency were correlated with the clinical signs sometimes seen following such treatment. Part IV. The previous parts dealt with the successful application of the larval irradiation technique to a parasite with an extensive migratory cycle. It was thought that this method might be less effective in parasites which undergo only a limited histotrophic phase - such as some of the gastro-intestinal nematodes. The experiments in this part indicated that a servicable degree of immunity could be induced in sheep against Haemonchus contortus.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: W PH Jarrett
• Keywords: Parasitology, Animal diseases
• Date of Award: 1966
• Depositing User: Enlighten Team
• Unique ID: glathesis:1966-72937
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 11 Jun 2019 11:06
• Last Modified: 11 Jun 2019 11:06
• URI: https://theses.gla.ac.uk/id/eprint/72937