Dirofilaria (D.) immitis is an important canine parasitic nematode in dogs. D. immitis parasitizes the right ventricle and pulmonary artery of dogs. An ivermectin and pyrantel pamoate compound (IPPC) was administered to dogs naturally infected with this parasite. IPPC is composed of 68.0, 136.0 and 272.0 ㎍ of ivermectin and 57.0, 114.0 and 227.0 mg pyrantel pamoate for small, middle, and large animals. Ivermectin has activity against nematodes and ectoparasites in dogs. Pyrantel pamoate is also effective against nematodes in dogs. Our results showed that this drug combination has good efficacy in D. immitis infected dogs.

This experiment has been investigated in order to examine larval migration inhibition activity of ivermectin, doramectin and ethanol against Anisakis simplex (A. simplex) in vitro. A. simplex larvae were obtained from the mackerel acquired from the fish market of Cheongju. They were divided into many groups and placed in culture dishes (40 larvae each) containing RPMI-1640, in the absence or presence of different concentrations of ivermectin, doramectin and ethanol. Ivermectin had a complete inhibition of larval migration at 72 h in all groups (10-300 ㎍/ml).

Toxocara (T.) canis and Trichuris (T.) vulpis are very important canine parasitic nematodes. T. canis parasitize in small intestine and T. vulpis parasitize in large intestine. In order to control of these nematodes, ivermectin and pyrantel pamoate compound was applied to the dogs infected with these parasites naturally and artificially. This drug was composed of 68.0 ㎍ of ivermectin and 57.0 mg of pyrantel pamoate for small animal, 136.0 ㎍ of ivermectin and 114.0 mg of pyrantel pamoate for middle animal, and 272.0 ㎍ of ivermectin and 227.0 mg of pyrantel pamoate for large animal. Ivermectin in this drug is activity to nematodes and ectoparisites. Pyrantel pamoate in this drug is also activity to nematodes. In this experiment, this drug had a good efficacy against T. canis and T. vulpis in the infected dogs.

Anthelmintic resistance against commonly used anthelmintics (ivermectin, levamisole, morantel and fenbendazole) was studied in naturally occurring gastrointestinal (GI) nematodes in adult sheep of unorganized sheep farms of district Ludhiana (Punjab). After qualitative and quantitative screening of faeces of 100 sheep, fifty sheep having eggs per gram of faeces (EPG) 500 were randomly selected and divided into five equal groups. Ivermectin @ 200 ìg/kg body weight and levamisole @ 7.5 mg/kg body weight, injected subcutaneously, in two different groups, were 99.08 and 98.17 per cent effective,respectively. Whereas, fenbendazole @ 7.5 mg/kg body weight and morantel citrate @ 6.0 mg/kg body weight, orally was 66.28 and 95.41 per cent effective and the fifth group was kept as untreated control with natural exposure to gastrointestinal nematodes. Hence, it was concluded that the naturally occurring GI nematodes of sheep were susceptible for ivermectin and levamisole, suspected for resistance against morantel citrate and were resistant to fenbendazole.