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.

This work evaluates the estrous cycle, gestation and lactation of rats treated with ivermectin. Control (GI) rats received distilled water; and the remaining were treated during 45 days with ivermectin (GII=0.5; GIII=1.0; GIV=2.0; GV=4.0; GVI=8.0 and GVII=10.0 mg/kg) by the oral route, the drug being administered every three day, in a total of 15 administrations. Colpocytological examinations were then performed during 15 consecutive days. Four animals from each group were euthanized, and samples of ovaries and uteri were taken for histological evaluations. The remaining animals were mated and treated throughout the gestation period and further until the 15th postpartum day. Colpocytologic examinations revealed that the animals of groups II, III, IV, V, VI and VII presented a higher incidence of the estrus phase, in comparison with the control group (group I). Histopathologic studies showed that the groups treated with ivermectin presented an increased concentration of hyperplasic endometrial glands, whereas the morphology of the ovary was not altered. The treatment did not affect the gestation lenght, the number of newborns nor did it caused congenital mortality or newborns malformations. During lactation, there was a significant slowering of the body weight gain of the litter. It is concluded that the treatment of female rats with ivermectin increases the incidence of the estrus phase. In addition, a definite deleterious effect is exerted on nursing animals as revealed by the reduced body weight gain of the litter. | O objetivo do presente trabalho foi avaliar o ciclo estral, gestação e lactação de ratas tratadas com ivermectina. 82 ratas albinas foram divididas em sete grupos. Os animais receberam água destilada (GI) ou diferentes doses de ivermectina, por via oral (GII=0,5; GIII=1,0; GIV=2,0; GV=4,0; GVI=8,0 e GVII=10,0 mg/kg). Os animais foram tratados por 45 dias, com ivermectina a cada três dias, totalizando 15 aplicações. Após esse período foi realizado exame colpocitológico durante 15 dias consecutivos. Ao final, quatro animais de cada grupo foram sacrificados e ovários e úteros retirados e processados para avaliação histológica. Os animais restantes foram acasalados e tratados com ivermectina, nas doses correspondentes a cada grupo, no 1º, 4º, 7º, 10º, 13º e 16º dias de gestação. Ao nascimento, os neonatos foram contados, analisados quanto à existência de defeitos congênitos, mortalidade e pesados até o 15º dia de lactação. Durante a lactação, as matrizes receberam novamente ivermectina no 1º, 4º, 7º, 10º e 13º dias. Nossos resultados mostraram que os animais dos grupos II, III, IV, V, VI e VII apresentaram maior incidência de estro em relação a GI. Quanto à histopatologia, os grupos tratados com a ivermectina apresentaram maior concentração de glândulas endometriais hiperplásicas. O tratamento não afetou tempo de gestação, número de neonatos, mortalidade ou defeitos congênitos. Na lactação observamos perda de peso na prole das matrizes tratadas com ivermectina. Pode-se concluir que a ivermectina, aumenta a incidência de estro e não deve ser indicada para uso em animais lactantes.

In order to evaluate the possible effect of ivermectin used on pregnant animals, Wistar rats were treated orally on sixth pregnancy day, with dosage of 20 and 60 times higher than therapeutic dosage used to treat scabiosis in dogs and cats. During all pregnant period, body weight, water and pellet food consuption of dams were determined. The dams were sacrificed at term for the evaluation of maternal and fetal parameters. The numbers of corporea lutea, post implantation loss and living and death fetuses were recorded. Also the organs of dams were removed, weighted and histopatologically examined. Fetuses were weighted, sexed, examined for external macroscopic malformations. Results showed absence of systemic and reproductive toxicity. It is concluded that ivermectin is no toxic to the dams and fetus, when administered in the beginning of organogenic period. | Avaliou-se a segurança da ivermectina (IVOMEC 1% injetável), um fármaco muito utilizado, administrado a ratas prenhes, no início da fase organogênica, em dosagem até 60 vezes superior (12mg/kg) a utilizada para o tratamento de escabiose em caninos e felinos. Os resultados revelaram ausência de toxicidade sistêmica e reprodutiva, fundamentados na ausência de alterações no desenvolvimento ponderal, consumo de água e ração, absorções embrionárias, massa relativa e exame histopatológico dos órgãos das ratas prenhes, bem como na massa corporal, vitalidade dos fetos, número de fetos por fêmea e alterações macroscópicas externas. Conclui-se pela segurança da ivermectina, quando administrada, em dose única, no início da fase de organogênese de ratas prenhes.

<p>The trial was carried out in nine different farms in the State of São Paulo to verify the effect of anthelmintic treatment with oxfendazole, levamisole and ivermectin in gastrointestinal nematode parasites in sheep. In each farm, the sheeps were randomly allocated in four groups: the first group was treated with oxfendazole at 4,5 mg/kg; the second one with levamisole at 7,5 mg/kg; the third one with ivermectin at 0,2 mg/kg and the fourth one was the untreated control. Faecal samples were collected from animals on the day of the treatment and seven days after that. After the treatment with oxfendazole, levamisole and ivermectin, significant reductions in nematode egg counts were verified in two, four and five farms, respectively. Haemonchus spp and Tnchostrongylus spp were the most prevalent parasites in the trial. The results suggest the occurrence of parasites with multiple anthelmintic resistance in the majority of the farms.</p> | O trabalho foi realizado em nove propriedades do Estado de São Paulo, com o objetivo de verificar o efeito da administraçõo de oxfendazol, ivermectina e levamisol sobre os exames coproparasitólogicos de ovinos. Em cada propriedade foram formados aleatóriamente quatro grupos de ovinos: o primeiro foi medicado com oxfendazol, na dose de 4,5 mg/kg, o segundo com levamisol, na dose de 7,5 mg/kg, o terceiro com ivermectina, na dose de 0,2 mg/kg e o quarto grupo foi o controle, não medicado. Colheitas de fezes foram realizadas no dia da vermifugação e novamente sete dias depois para a realização de exames coproparasitológicos. Após a administraçâo de oxfendazol, levamisol e ivermectina, foi verificada redução estatística significativa nas contagens de ovos por grama de fezes (OPG) em duas, quatro e cinco propriedades, respectivamente, sendo Haemonchus e Tnchostrongylus os parasitas com maior ocorrência no experimento. Os resultados sugerem, na maioria das propriedades, a presença de parasitas com resistência múltipla aos anti-helmínticos testados.