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Layer Changes in the Lungs of Hare Provoked by the Parasite Protostrongylus-Commutatus

PAJERSKY A, SVARC R, MEDVEDOVA M
Veterinarni Medicina 37, 1992, 249-255

The pathomorphological changes in the lungs of hare [Lepus europaeus Pallas, 1778] provoked by the parasite P. commutatus [Diesing, 1851] are macroscopically manifested as layer and nodular changes. With regard to the fact that the layer changes are suggesting the hatching nodules of protostrongyloses of small domestic ruminants, we have decided to rate them separately because of the differentiation. The layer changes on the surface of hare's lungs become evident as areas of emphysema, inflammation and induration. The emphysematous changes are macroscopically evident in the form of lobular formation [Fig. 1]. Histologically, it was found out that the emphysematous effect was limited by an area of compressed lung structures without perspicuous signs of the development of atelectatic changes [Fig. 2]. The emphysematous changes are causing prominent exudative inflammatory processes in the bronchi and bronchioli provoked by unfertilized and desintegrating eggs of parasites. Inflammatory layers are macroscopically evident as solid brown-reddish areas [Fig. 3]. Their macroscopic manifestation is transient. It is qualified by the stages of the inflammation itself. It is possible to put down the stage of manifestative development of the changes in the inflammatory areas only by continual examinations of hare's lungs all year round. Unfertilized eggs and grounded, desintegrating larvae of protostrongylus are provoking the inflammatory reactions which may lead in the layer changes to the obliteration of bronchioli [Fig. 6], which is macroscopically evident as induration [Fig. 7]. The bronchioli are oblitered so that the phagocytic ability of monocytes is transformed to a reparative ability. >From the etiological point of view the primary cause of the origin of layer changes is either unfertilized eggs or grounded desintegratin larvae of the parasite P. commutatus which stimulate the inflammatory reactions. With regard to the course of the inflammatory reactions the blood elements are participating in the formation of the particular forms of the layer changes of the hare's protostrongylosis. It is mainly the penetration of eosinophilic granulocytes. Participation of particular cellular parts of the inflammatory process in the layer changes creates such conditions that these affections lead to regeneration in the majority of cases. Prominent oedema accompaying the process of regeneration is a predisposing factor for asserting the secondary infections of various etiology. Therefore from the pathogenetical point of view, and also from the prognostical viewpoint layer changes are not favourable


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