ON THE "WAHI" OR "KOSE" DISEASE, AN ELEPHANTIASIS-LIKE DISEASE, IN CATTLE

Abstract

With regard to the etiology of an elephantiasis-like disease known as "Wahi" or "Kose" in our native cattle, I reported in this journal Vol. VI, No. 2 that from the histological point of view the causal agent of this disease was a kind of microfilaria. In this paper I want to state the results obtained by further experiments on this problem.Although the microfilaria appears in the blood the year round, they are found more numerous in summer. Their appearance in the blood of peripheral veins seems tohave a slight periodicity. A great number of microfilaria are observable at 6-9 o'clock in the afternoon, but it is not so remarkable as in the case of embryos of Filaria bancrofti. The appearance resembles the embryo of a filaria, but the adult worm is not yet decided. Therefore, I have attempted to find them by means of post-mortem examination.As the result of this examination, many filaria-like worms were discovered in the abdominal cavity of the affected cattle. The worm was long, thread-like in size and white in colour, and the male was smaller than the female. It was attenuated at both ends. The tail of the male was coiled up spirally; that of the female was straight or slightly curved. The uterus contained eggs and embryos in a remarkable number, and the appearance of the latter resembled closely the microfilaria in the blood.In order to determine whether the embryos can appear in the circulating blood, I put these worms into the abdominal cavity of rabbits. As the result of this experiment I found the microfilaria appeared in the blood of those animals in 3 days after the operation and on the 10th day they were found in maximal number.Furthermore, I discovered that these worms could be classified into two species by the microscopical examination. One species had strong dorsal and ventral teeth separated by a wide depression from the centre of which arose a semi-circular lip-like elevation. The caudal region of the female was loosely spiral and terminated in a knob-like extremity surrounded by an irregular ring of pointed spines and bearing a pair of lateral appendices close to the extremity. The tail of the male was closely spiral and there were four pairs of preanal and four pairs of postanal papillae, but occasionally one papilla was found closely in front of the cloaca.The other species closely resembled the former in shape, but the mouth was very small, about one-half the former in diameter, and the posterior extremity of the female terminated in a smooth knob.From these findings I should like to regard the former, as Boulenger, as Setaria labiato-papillosa and the latter as S. digitata. and to consider that the microfilaria in the blood of affected cattle is closely related to these worms.