[Pathogenic role of O. venulosum in lambs].

Studied was the effect of an experimental infection of lambs with 1000 and 4000 larvae of Oesophagostomum venulosum on the activity of some more important serum enzymes, the level of sulfhydryl groups, and the level of sugar. It was found that the activity of glutamic acid oxal-acetate transaminase and lactic acid dehydrogenase rose, and that of alkaline phosphatase dropped. At 4000 larvae the level of glutamic acid pyruvate transaminase rose.

[Changes in serum proteins and their fractions in lambs with experimental Oesophagostomum venulosum infection].

Studied was the effect of an experimental infection with Oesophagostomum venulosum on the total serum protein and the protein fractions. Two test groups of lambs were used--with a weak and a strong infection, respectively. It was found that on the seventh day of infection there started a rise of the total serum protein.

[Species of Oesophagostomum in sheep and goats in Stara Zagora District].

The study of small ruminant animals in the district of Stara Zagora has revealed that only one species of the Oesophagostomum genus could be found--Oesophagostomum venulosum (Rudolphi, 1809), Railliet et Henry, 1913. There are some morphological and metrical differences in the imaginal and larval stages between this species found in sheep and goats and the one described in the literature. It seems, therefore, that there exists great plasticity of these signs, and this should be taken into consideration in the identification of the species belonging to this genus.