Japanese Journal of Veterinary Research;Volume 4, Number 3

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STUDIES ON "KASEN" OF HORSES IN HOKKAIDO : III. RESEARCH ON THE ACTUAL STATE OF THE DISEASE

NAKAMURA, Ryoichi;MATSUHASHI, Akira;YAMASHITA, Nakaichi;YAMAMOTO, Takesaburoh

Permalink : http://hdl.handle.net/2115/1692
JaLCDOI : 10.14943/jjvr.4.3.81

Abstract

As far as shown by the above described data, the cause and treatment of "kasen" are not yet entirely known. Microfilaria of Onchocerca cervicalis had been thought to be a causal agent of "kasen" for many years. However, the mechanism of the occurrence of the itchiness is not defined at all. As the investigations relating the microfilaria need the enormous expenditures and many hours, they have not yet been carried through. From many years ago, all possible therapeutic methods have been used in Hokkaido for treating the disease during the period of affection. Then, since no entire healing was found, the owners gave up all hope of recovery. Unexpectedly, the authors obtained good results by using antihistamine preparation as was also tried by RIEK. So the authors have come to suspect that the disease may be related to a certain allergic reaction as RIEK and ISHIHARA and UENO are also thinking. What is the cause of the allergic reaction? From the view point of this question, the research on the actual state of the disease was conducted. The results thus obtained from the 200 patients are summarized as follows. 1. The sickness occurs from late spring or early summer and disappears naturally towards the cool season. 2. The patients are found more often in districts of paddy field and waste land. 3. The young horses are easy to get sick, but also the adults and old horses were affected. 4. The degree of the itchiness runs parallel with the rise and fall of atmospheric temperature. 5. Further, the itchiness runs also parallel to the increase and decrease in appearance of bloodsucking insects. 6. The bloodsucking insects appear from late spring and disappear towards the cool season. 7. The bloodsucking insects are apt to appear at the time of after and before rain and that of clear weather and the serious itchiness may be found at those times. 8. The bloodsucking insects appear more frequently from before sunset to dark and the severest itchiness are observed in parallel to their appearance. 9. The insects are horse fly, black fly, biting stable fly, biting midge and, etc. However, the relation between the insects and the disease has not yet been clarified in Hokkaido. 10. The coat hairs of almost all the patients are black or black-brown and white color was found in only 2 cases. Bloodsucking insects are apt to be more strongly attacked by an object colored black or black-brown than by one of other colors. 11. Injection of antihistamine preparation and spray of insecticides may have some effectiveness for treating and controlling the disease. However, further examination may be needed. Considering from above summary, the disease have a close connection with bloodsucking insects. If it is related to an allergic reaction, "kasen" may be caused by the development of a hypersensitivity to the bites of some insects. YAMASHITA et al. collected 3 kinds of sandflies infesting the lesions of the patients, viz., Culicoides obsoletus, Culicoides pulicaris var. ocellaris and Culicoides sp. But the relation between the disease and these sandflies is unknown. Therefore, parasitological and immunological investigations will need to be conducted for complete understanding of the disease. If the present work furnishes some information to further the research on the cause and therapy, the present writers will be very happy.

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