犬糸状虫ミクロフィラリア寄生犬にイベルメクチンとジエチルカルバマジンを投与してみられる副作用の比較

Abstract

The present study was designed to find out whether administration of ivermectin (IVM) to microfilaremic dogs causes the shock-like reaction that is well known as an adverse effect of diethylcarbamazine (DEC). Both IVM and DEC were given to the same dogs, and the occurrence of adverse reaction was compared between the two drugs. Thirty dogs, which had an average microfilaria count of 395 (11-3, 309)/20μl of peripheral blood, were used for the experiment. A single oral administration of IVM was given to each of the 30 dogs at the dose of 10μg/kg, and observation was continued for the following 7 days. In this period, there appeared no abnormality in clinical signs, WBC count, or in any of 13 items ofplasma biochemical test. There was no reduction in microfilaria count either after the administration. The DEC experiment was carried out after the IVM experiment was completed. A single oral administration of DEC-citrate was given to each of the 30 dogs at the dose of 6mg/kg. For the following 24 hours, the animals were observed for the appearance of clinical signs, and examined with the same test protocol as in the IVM experiment. Five dogs (16.7%) were judged to have suffered the shock-like reaction from one to three hours after the administration of DEC. In these dogs, the clinical signs were accompanied by an increase in WBC and marked rises in GOT, GPT and ALP, which indicated severe hepatic impairment. Even in the other 25 dogs that showed no clinical signs, similar changes were observed in the WBC and the biochemical test values, although the changes were milder.Thus, no abnormality associated with IVM administration was observed, even in the dogs that showed theDEC-associated shock-like reaction. Therefore, it appears that IVM has no tendency to cause the shock-like reaction which can occur following DEC administration in microfilaremic dogs.