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.

Experimental studies on organomercury poisoning in chickens in Iraq.

For 164 days mature chickens received a daily diet containing 40 g of wheat treated with organomercurial fungicide and 80 g of untreated diet. A control group received 120 g of normal diet daily. The experimental group was then split - half receiving the same diet for a further 155 days, by which time all had been killed or had died, the other half being fed the same diet as the controls. No cases of mercurialism were seen in the experimental group, although 2 died after 143 and 319 days respectively. Egg production fluctuated as between the groups. Mercury levels in egg albumin showed high peaks after 98 and 108 days. After the feeding of contaminated wheat had been discontinued the albumin mercury level did not fall consistently below 0.5 mg/kg for 127 days. Levels in egg yolk always remained below the level in wheat and dropped to zero 49 days after feeding of the dressed wheat had been discontinued. Mercury levels found in tissue were similar to those described by other authors. Levels in the edible parts of the single cock examined exceeded those in the hens. Implications of these findings for public health decisions on the use of chicken and eggs as food when the birds have had access to contaminated grain are discussed.