1976 Volume 1976 Issue 13 Pages 8-18
There were three large-sized solitary cysts in the liver of each of two horses, Nos. 1 and 2. Horses 1 and 2 were a 16-year-old halfbred gelding and a 22-year-old female Thoroughbred born in Ireland and England and imported into Japan at the age of 6 and 5, respectively. All the cysts were unilocular and had numerous brood capsules containing protoscolices in the interior. Their wall consisted of an inner germinar layer, an outer cuticular membrane, and calcareous corpuscles. Each cyst was surrounded by the host capsule . All the cysts were morphologically identified as those of Echinococcus unilocularis (larvae of E, granulosus). In horses 1 and 2, the cysts were found to belong to E . polymorphus and E. cysticus, respectively, when classified on the basis of morphology. All the cysts were also diagnosed as those of Es fertilis on the basis of the existence of protoscolices . The following surmise may possibly be made on the hepatic hydatid cysts in the two horses : It is within the bounds of possibility that the cysts may be larvae of E, granulosus equinus and that the infestation of the parasite may have occured to the two horses in Ireland and England, respectively.
