The efficacy of a beef-based, chewable formulation of ivermectin against a mixed infection of Ancylostoma braziliense and A tubaeforme was determined in cats. Ivermectin administered orally at approximately 24 microgram/kg of body weight was 92.8% effective against adult A braziliense and 90.7% effective against adult A tubaeforme. The number of eggs per gram of feces had decreased 98.1% by 7 days after treatment. Clinical signs of hookworm disease also decreased after treatment. Location of adult parasites within the small intestine, percentage of infecting larvae that developed to the adult stage, and egg size in cats with infections of A braziliense and A tubaeforme were similar to those reported for cats with separate infections of either species.

The efficacy of netobimin against digestive tract strongyles and the small lungworm Muellerius capillaris was tested in a dairy goat herd. The drenches were given orally at the rate of 20 mg/kg of body weight once, 10 mg/kg on 2 successive days, or 7.5 mg/kg on 3 successive days. Fecal egg counts and larval counts were done 8 days before and on the day of drenching; further counts were performed on postdrenching days 8 and 18. Two goats were necropsied, 1 on postdrenching day 5 and 1 on day 10 in the group treated on 3 successive days. The fecal egg counts were reduced by 44 to 79% depending on dosage on postdrenching day 18; the remaining worms were Trichostrongylus colubriformis. The larval counts of M capillaris were reduced by 72 to 92%, depending on dose. The reduction was significant in all the treated groups, compared with that in the control group. The use of netobimin at the dosage of 10 mg/kg given on 2 successive days or 7.5 mg/kg given on 3 successive days might be recommended to treat goats infected with Muellerius spp and digestive tract strongyles.

Twelve Holstein calves mere used to determine the prophylactic efficacy of ivermectin against challenge exposure with gastrointestinal and pulmonary nematodes. Two groups of 6 calves (mean body weight, 205 kg) each were formed by restricted randomization according to body weight. Group-l calves served as nonmedicated controls. Each calf of group 2 was orally given one prototype sustained-release bolus designed to deliver ivermectin at a continuous daily dose of 8 mg. Third-stage nematode infective larvae were given to the calves on posttreatment days 28 and 42. The calves were euthanatized 77 or 78 days after treatment. Ivermectin was 100% effective (P < 0.05) in preventing the establishment of infection by Haemonchus placei, Ostertagia ostertagi, Cooperia spp (C punctata, C oncophora, C surnabada), Nematodirus helvetianus, Oesophagostomum radiatum, and Dictyocaulus viviparus and was > 99% effective against Trichostrongylus axei. Incidental infection by Trichuris spp was reduced by 94% (P = 0.08).

The efficacy of febantel (5.0 mg/kg) against naturally acquired infections of gastrointestinal nematodes was evaluated in a controlled test in calves during the winter. Twenty steers were allotted to either control or treatment groups of 10 animals each. Seven days after treatment, calves were euthanatized and necropsied for recovery of parasites. Febantel was highly effective against adults of Ostertagia spp (88.6% efficacy based on median), Cooperia spp (97.7%), Trichostrongylus spp (98.2%), Oesophagostomum spp (100%), and Bunostomum phlebotomum (100%). Effects of treatment against adults of Nematodirus spp (100%) were not significant, whereas, degrees of infection of Strongyloides papillosus, Capillaria sp, and Trichuris sp were insufficient for evaluation. The activity of febantel was variable in controlling inhibited and late fourth-stage larvae of Cooperia spp (100% and 100%, respectively) and Ostertagia spp (-81.5% and 36.7%). Numbers of larval Nematodirus and Capillaria sp were insufficient for evaluation. Overall, febantel administered at 5.0 mg/ kg reduced populations of adult and larval strongyles and other gastrointestinal nematodes in calves by 80.7% (P = 0.002). An unexpected finding during the trial was the recovery of Oesophagostomum venulosum from all control calves.

gastrointestinal nematodes, calves (exper.), efficacy of ivermectin given subcutaneously or given orally as drench or paste

common internal helminths of swine, flubendazole, dose range and efficacy studies

A controlled test was performed to titrate the anthelmintic dosage of dienbendazole in 24 mixed-breed ponies naturally infected with Strongylus vulgaris, S edentatus, and small strongyle species, as determined by parasitic egg and larval counts in feces. Comparison of results of treatment was made among 3 dienbendazole dosages--2.5, 5, and 10 mg/kg of body weight-and a gum (excipient) mixture given by nasogastric intubation. All ponies were euthanatized and necropsied at 7 or 8 days after treatment. Trichostrongylus axei, Habronema muscae, S vulgaris, S edentatus, small strongyles, and Oxyuris equi were efficaciously eliminated in response to all doses of dienbendazole; Gasterophilus spp were not affected by any dose. There were not sufficient numbers of Draschia megastoma, Anoplocephala spp, or Parascaris equorum in the ponies to evaluate drug effect. Changes in the appearance of the intestinal lining were dose-dependent; in the ponies treated with 5 and 10 mg of dienbendazole/kg, the mucosa appeared clean and smooth, though in ponies given 2.5 mg/kg, it appeared clean, but was nodular and moderately reactive to embedded immature small strongyles. In the gum mixture-treated ponies, the large intestinal mucosa was inflamed, with edematous areas, in response to infections caused by large and small strongyles. A limited clinical titration was done in 12 ponies that were fecal culture negative for S vulgaris larvae, although other strongyles were detected. Two ponies in each of 6 groups were given the following dosages: 0 (gum mixture only), 0.5, 1, 2.5, and 5 mg of dienbendazole/kg. One group of 2 ponies was given 5 mg of fenbendazole/kg as a standard treatment control. On the basis of pre- and posttreatment fecal examinations (for egg and larval counts), dienbendazole at dosages that ranged from 1 to 5 mg/kg was highly effective and as effective as fenbendazole given at a dosage of 5 mg/kg. Small strongyles were most responsive to fenbendazole and dienbendazole at all dosages. Egg production by S edentatus was eliminated by administration of fenbendazole and dienbendazole (at dosages of 2.5 and 5 mg/kg). Administration of dienbendazole at a dosage of 1 mg/kg resulted in partial elimination of S edentatus egg production. Trichostrongylus axei egg production was eliminated by administration of dienbendazole at dosages of 2.5 and 5 mg/kg, but not by the administration of 1 mg/kg. Parascaris equorum egg production was eliminated from the single infected pony given dienbendazole at a dosage of 5 mg/kg.

helminths of naturally infected dogs and cats, effect of febantel/praziquantel paste

intestinal parasites, dogs, prevalence, sex of host and neutering procedure, age of host, mixed infections, diagnosis by fecal examination