Japanese Journal of Veterinary Research;Volume 4, Number 3

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STUDIES ON ECHINOCOCCOSIS : III. ON EXPERIMENTAL INFECTION IN DOGS, ESPECIALLY ON THE DEVELOPMENT OF ECHINOCOCCUS GRANULOSUS (BATSCH, 1786)

YAMASHITA, Jiro;OHBAYASHI, Masashi;KONNO, Seiji

Permalink : http://hdl.handle.net/2115/1695
JaLCDOI : 10.14943/jjvr.4.3.113

Abstract

1. Experimental infections of Echinococcus in dogs were carried out by using the Australian sheep strain of hydatid cyst. 2. The morphological observations and comparative dimensions of the cestodes on the 16th, 17th, 35th, 135th and 375th day after ingestion of the larval cestode were described respectively. 3. This species is Echinococcus granulosus (BATSCH, 1786). 4. The cestodes occur in the duodenum and anterior part of jejunum with limits of about 40 to 60 cm. 5. In young specimens on the 35th day after infection, the strobila shows the adult form already, while the embryophore of egg is out of sight and the oncosphere is not completed. 6. The first occurrence of the egg in the feces from 2 dogs was on the 48th and 61st day after ingestion of the larval cestode respectively. 7. There is a period in which the occurrence of the egg is interrupted ; this period is about 1 or 1.5 months. Perhaps this is the period from the first removement to the next one of gravid proglottid. 8. The proportions of the development of the cestodes depend upon the average dimensions on the 16th, 35th, 135th and 375th day after ingestion of the larval cestode. Those proportion are as follows : (1) Length of strobila, 1 : 3 : 4 : 8 (2) Size of rostellum, 1 : 1.4 : 1.5 : 2 (3) Size of hook ; Large hook, 1 : 1.3 : 1.5 : 1.6 Small hook, 1 : 1.1 : 1.2 : 1.3 (4) Size of sucker, 1 : 1.1 : 1.3 : 1.5 The proportions of the development of cirrus sac in the last proglottid of cestodes on the 35th, 135th and 375th day show a very good development. 10. The form of uterus in the gravid proglottid of this species is widely variable. The lateral succulations of the uterus become more in number and their shape changes into lateral branch with the development of cestodes. 11. From this work the present authors are quite convinced that further work, based on experimental infections, is needed to clarify important relationships involving the species of Echinococcus and then the intermediate and final hosts.

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