The pathogenicity of haemonchosis in sheep and goats in Iraq: 1. Clinical, parasitological and haematological findings.

The response of Awassi sheep and the local breed of Iraqi goats to primary infection with a prevalent trichostrongylid nematode, Haemonchus contortus, was compared by examining their worm burden and the pathogenic effects of the parasite on these hosts following experimental infection. The results showed that the goats had lower worm burdens and had suffered less severe clinical and haematological disturbances than the Awassi sheep. The worm counts in sheep were higher than in goats but the count of the mucosal phase of the larvae was higher in goats. These differences are possibly immunologic in origin though a genetic resistance may operate, primarily at the level of worm establishment. The pathophysiological changes are correlated with parasitological and clinical observations in the two host species.

Gross pathology and histopathology of haemonchosis in sheep and goats in Iraq.

The response of Awassi sheep and a local breed of goats to H. contortus, the prevalent ovine and caprine strongyloid species in Iraq, was studied. A dose of 500 H. contortus (sheep origin) larvae kg-1 body wt. induced clinical and pathological changes of haemonchosis. Although the percentage recovery of worms was higher in sheep, the pathological (gross and microscopic) changes were more marked in infected goats. The extensive abomasal changes noted in goats were, in general, accompanied by a higher density or larvae in the gastric wall; the pathology did not necessarily depend upon parasite count alone and a definite relationship could not be established. The tissue changes in the goats are possibly of immunological origin, although a genetic resistance may operate, primarily at the level of worm establishment.

Spontaneous pineal body tumours (pinealomas) in Wistar rats; a histological and ultrastructural study.

The pathology of 5 cases of pinealomas in Wistar rats used in long-term toxicological studies is described both grossly, microscopically and ultrastructurally, together with a review of the related literature.

Experimental study of the effect on rabbits of the injectable contraceptive medroxyprogesterone acetate, cholesterol feeding and drug-atherogenic diet combination.

Medroxyprogesterone acetate was given alone or in combination with a cholesterolll-rich diet. Total serum cholesterol levels in treated rabbits was significantly different from those of the control on most occasions during the experiment, and in the controls it remained essentially the same throughout the experimental period. There was a relationship between lesions induced and the raised serum cholesterol, but there was no regression of the appearance of fibrous plaques after discontinuation of the cholestero supplement.

Study on the pathogenicity of ostertagiosis due to Ostertagia circumcincta in sheep, in Iraq.

The response of Awassi sheep to ostertagia circumcincta, the most prevalent ovine strongylid species in Iraq, was studied. A dose of 100000 larvae of O. circumcincta (Iraqi strain) induced moderate clinical symptoms of ostertagiosis. These symptoms were correlated with elevated pH of the abomasal fluid and increased plasma pepsinogen levels. There was no evidence of larval inhibition since the majority of the fourth stage larvae (L4) continued their development. No appreciable loss of worm population was observed and most of the parasites survived and exhibited a prolific egg-laying potential six months after initial infection. Assessments of the pathophysiological changes were performed and correlated with parasitological and clinical observations. The Awassi breed of sheep, the most prevalent in the Arab Middle East, seems to be more susceptible to ostertagiosis than other breeds and there was no spontaneous self-cure in this breed.