Strongylus vulgaris (larvae), Trichostrongylus axei (adults), ponies (exper.), efficacy of ivermectin, controlled tests

Sarcocystis cruzi, calves fed sporocysts of 2 different isolates from coyotes, number of merozoites in peripheral blood, duration of parasitemia, and extent of multiplication of merozoites

gastrointestinal parasites, horses, anthelmintic efficacy of ivermectin, adverse local or systemic reactions not observed

The activity of ivermectin against common nematode parasites of sheep was examined in 2 experiments. In the 1st experiment, 14 sheep with naturally acquired infections were assigned to 2 groups of 7 sheep each. Sheep in 1 group were treated with 200 micrograms of ivermectin/kg of body weight and the remainder served as nontreated controls. In the 2nd experiment, 15 sheep with experimentally supplemented infections (including a benzimidazole-resistant strain of Haemonchus contortus) were assigned to 3 groups of 5 each. The 1st group was treated with 200 micrograms of ivermectin/kg, the 2nd was treated with 88 mg of thiabendazole/kg, and the 3rd served as nontreated controls. Ten to 12 days after treatment, all sheep were euthanatized and necropsied, and the parasites they harbored were recovered and identified. Efficacy of ivermectin was excellent (greater than 96%) against Dictyocaulus filaria, H contortus, Ostertagia circumcinta, Marshallagia marshalli, Trichostrongylus axei, T colubriformis, and T vitrinus. Treatment was not as uniformly effective for Nematodirus spathiger (73% to 85%), N filicollis (80% to 96%), Cooperia curticei (92% to 100%), immature nematodes (92% to 100%), and early 4th-stage larvae (46% to 100%). Efficacy of thiabendazole was poor for H contortus (42%) and early 4th-stage larvae in the abomasum (52%), but approached 100% for most of the other parasites.

Dermacentor andersoni, transmission of Anaplasma marginale to splenectomized calves by injection of gut homogenates from incubated vs. non-incubated adult ticks

Cytauxzoon felis, susceptibilities of bobcats, 4 species of domestic farm animals, 9 species of laboratory animals, and 17 wildlife species to infection using infective material from domestic cats, Lynx rufus floridanus developed cytauxzoonosis with signs and lesions identical with those of domestic cats and died of disease, Lynx rufus rufus developed subclinical persistent parasitemia, results indicate that both species of bobcats may serve as reservoir hosts; sheep developed low persistent parasitemia without clinical signs, while other species of animals failed to produce evidence of cytauxzoonosis

Eimeria tenella, chickens (exper.), alpha-difluoromethylornithine promising for preventive chemotherapy, perhaps prevents schizont formation, anticoccidial effect possibly due to inhibition of putrescine biosynthesis; immunity to reinfection after treatment

nematodes, lambs, 11 anthelmintics compared using medicated feeds or multiple small doses

Trichuris vulpis, Ancylostoma caninum, and other helminths, dogs, efficacy of febantel paste formulation at various dosage levels, paste appeared palatable and there were no apparent adverse effects observed

Parafilaria bovicola, field survey of insect vectors collected from cattle, bleeding-point on cows and prepatent period studies, experimental infection of laboratory-raised Musca autumnalis with third-stage larvae, transmission of third-stage larvae to calves (clinical and pathologic findings)