Toxicity of ivermectin in Jindo-dogs 1. Clinical and hematological observation

진돗개에서 ivermectin의 독성 I. 임상증상과 혈액학적 변화 관찰

Ivermectin is a synthetic derivative of the naturally occurring avermectin $B_{1a}$ (22, 23-dihydroavermectin $B_{1a}$) and $B_{1b}$ (22, 23-dihydroavermectin $B_{1b}$), It is widely used as antiparasitic and pesticidal agents because of its remarkably potent and broad spectrum of antiparasitic activity. Although the drug has shown excellent anthelmintic effects, development of toxicosis in some animals such as the Collie species of dog is well documented. However, no studies have been reported on the toxic effects of the drug in Korean native animals such as the Jindo dog. The toxic effect of ivermectin was evaluated in 25 Jindo dogs divided into five groups which were orally administered with ivermectin at dosage levels of $200{\mu}g/kg$, $300{\mu}g/kg$, $600{\mu}g/kg$ and $2,500{\mu}g/kg$ of body weight, respectively. Toxic signs were not observed in the groups receiving $200{\mu}g/kg$ and $300{\mu}g/kg$ B.W. ivermectin. One dog developed mild clinical signs of toxicosis in the group receiving $600{\mu}g/kg$ dosage of ivermectin. In the group with $2,500{\mu}g/kg$ dosage, all dogs developed mild (salivation, drooling, vomiting, mydriasis, and/or confusion) and/or moderate (ataxia and tremors) clinical signs of toxicosis. Hematologic changes were not observed in the groups receiving $200{\mu}g/kg$, $300{\mu}g/kg$ and $600{\mu}g/kg$ B.W. ivermectin. In the groups receiving $2,500{\mu}g/kg$ B.W., total erythrocyte counts, total and differential leukocyte counts and hemoglobin levels were not affected by drug. Aspartate aminotransferase levels were increased after administration of ivermectin, while serum cholesterol and blood glucose levels were decreased.