RADIOLOGIC DETECTION OF OVINE HYDATIDOSIS

Unilocular hydatid disease in humans is of world-wide importance. While surgical removal is the usual treatment, the drug mebendazole has been reported as being active against the cyst wall; other potentially valuable drugs are likely to become available. Naturally infected sheep would be a suitable model for testing drugs against hydatid disease, and a method for selecting infected animals from flocks in areas with a high incidence of this condition would be valuable. To determine whether radiographic examinaiton of the thorax would be a satisfactory method of identifying cysts, the authors radiographed and then killed 93 cull ewes. At necropsy, the lungs were examined, and the nature and distribution of cysts were noted and compared with the findings obtained separately by radiology. A similar study was made on a sheep infected experimentally with a large number of Echinococcus granulosus ova. The technique of thoracic radiography in sheep is described. These studies indicate that there are four different morphologic manifestations of ovine hydatid cyst that may be reliably identified by radiologic examination. They also show that thoracic radiology provides a method for detecting active hydatid infection in sheep and for following the progress of individual cysts.