Canine Piroplasmosis. V. Further Studies on the Morphology and Life-History of the Parasite

Abstract

In the present paper we describe the results of further investigations on the morphology and staining characters of Piroplasma canis, as well as a large number of observations on the living parasites. Our previous papers (1905) contained the results of studies preliminary to the investigation of the life-history of the parasite, but further work was unavoidably interrupted owing to the difficulties attending this form of research—we unaccountably failed to transmit the disease after several passages through dogs, and met with great difficulties in rearing progeny from infected ticks. Consequently the observations had to be discontinued until, after several failures, infected ticks (Haemaphysalis leachi) capable of transmitting the disease, had been received from South Africa through the kindness of Mr C. P. Lounsbury, Government Entomologist, Cape Colony. With this fresh strain of the disease we have succeeded in demonstrating various points in the morphology of the parasite which have hitherto escaped observation, and have worked out its method of multiplication in the living blood. Further studies have also been made on the vitality of the parasite outside the body in culture fluids, but these and other studies on the cycle of development within the tick are reserved for future communications.