狗狗注射伊维菌素好吗？
【1】关于伊维菌素 伊维菌素（Ivermectin），又名灭疥霉、除虫菌、兽用蚊蝇净等，是一种广谱抗寄生虫药。1970年由英国研究人员发现并首次合成，商品名为Mectizan(梅塔佐恩)，目前已经被世界各地的药物生产商生产出来用于各种不同种类的动物身上。其作用机理是干扰中枢神经和血液循环系统的神经激素——多巴胺与γ-氨基丁酸之间相互作用，影响昆虫和寄生虫的神经传导物质，阻断神经系统对信息的传递，导致昆虫或寄生虫死亡。 目前临床上使用的伊维菌素，根据化学结构的不同分为四甲醚类和多亚甲基二氧吡啶类两种类型，包括伊维菌素、阿福纳霉素及多拉菌素三种主要产品。其中，多拉菌素是目前应用最广泛的伊维菌素衍生物之一[2]。
【2】使用剂量和给药方式 关于人用和使用给狗用伊维菌素的剂量和频次有非常详细的说明。 人用的用法如下： Ivermectin is an antihelminthic medication commonly used in humans. The recommended dose for ivermectin for parasitic infestation (eg， hookworms，[48] roundworms [ascaris lumbricoides]) is a single oral administration of 200 mcg/kg body weight given once weekly for three weeks or less，[3，4] while the dosing regimen for scabies and headlice is two doses at least one week apart with either 150 mg/70 kg or 200 μg/kg as a single oral dose.[5] It can also be administered by ophthalmic drop solution to treat onchocerciasis and lymphatic filariasis. There are no studies demonstrating efficacy of this route of treatment for these infections; however， it appears that ocular administration is better tolerated than other routes of delivery without reducing serum drug levels.[6]
Doses for veterinary medicine vary greatly based upon the animal’s size， condition and type of infection. For example， the most common use of IVM for dogs is in controlling fleas where a dose of approximately 0.03 mg/lb taken monthly works quite well depending on the age， size and health of your dog. A veterinarian might even prescribe lower dosages according to specific needs. When treating a horse with IVM， a vet will usually order between 0.5 – 1 mg per hundred pounds of weight per month， again adjusted according to their individual needs. In some instances， you may find higher dosages needed when using IVM against strong parasites such as Strongyloides stercoralis， which tends to resist treatment more often than others.
The FDA has approved two formulations of human IVM for use topically：a creme and a lotion. Both have been found effective and safe if applied appropriately to the skin or ears. They work best to treat external parafilarial nematodes like the ear mite and mange mites. This is