Comparative efficacy of levo-tetramisole, parbendazole, and piperazine citrate against some common helminths of turkeys.

Levo-tetramisole given to turkeys by capsule at 30 mg/kg of body weight was completely effective against adult and immature Ascaridia dissimilis, 98% effective against adult Heterakis gallinarum, and 89% effective against adult Capillaria obsignata. When given at 0.05% and 0.1% of the feed for one day it was completely effective against adult Ascaridia, effective against Heterakis (0.05%--84 and 91%, 0.1%-83%), less effective against immature Ascaridia (0.05%-61 and 91%, 0.1% -46% ), and relatively ineffective against adult Capillaria (0.05%-0 and 23%, 0.1% -41%). In two of three trials, feed intake by medicated birds was lower than by the controls, particularly at the 0.1% level. This may account, in part, for the decreased efficacy with this regimen. Parbendazole given by capsule at 30 mg/kg was effective against Heterakis (97%), but ineffective against adult and immature Ascaridia and adult Capillaria (40, 14, and 27%, respectively). When this drug was given in feed for one day at levels of 0.05 and 0.1%, it was generally more effective than when given by capsule. Feed intake was not affected by the drug. Piperazine citrate was 100% effective against adult Ascaridia when given at a level of 0.4% (base) in feed for two days, but only 48% effective at the 0.1% level. With both regimens it was moderately effective against adult Capillaria, but ineffective against adult Heterakis. Feed intake was not affected by the drug. Piperazine, dl-tetramisole, and parbendazole have been reported to be effective against certain helminth parasites of chickens (piperazine-Gibson, 1965, and others; dl-tetramisole-Thienpont et al., 1966, Bruynooghe et al., 1968; parbendazole-Actor et al., 1967). To our knowledge, little data are available on the effect of these anthelmintics against the same or closely related helminths of turkeys, except for a single report by Edgar et al. (1957) on piperazine hexahydrate. Thus, there is a lack of definitive information on the efficacy of these anthelmintics against common helminths of turkeys. Accordingly, controlled trials were conducted with turkeys harboring naturally-acquired infections of Ascaridia dissimilis, Heterakis gallinarum, and Capillaria obsignata. All available data on the efficacy of tetramisole against chicken helminths were obtained with the dl compound, but because the anthelmintic activity of this chemical has been reported to reside primarily in the levo isomer (Bullock et al., 1968), only 1teramisole was used in the trials reported here. MATERIALS AND METHODS Turkeys employed and source of infection Approximately equal numbers of male and female Small Beltsville White turkeys five to seven months of age were used. In four of five trials there were slightly more hens than toms, and in the other the number of both sexes was equal (Table I). The age and weights of the birds in each trial were comparable, except that the toms in each case weighed about twice as much as the hens. The turkeys were raised at this laboratory and placed on helminth-contaminated, small bare lots 10-12 weeks after hatching. After two to four months, 1 The authors acknowledge with appreciation the technical assistance during the course of this work of Messrs. L. M. Wiest, H. Saiontz, S. B. Akerele, and Tsegaye Habte. TRANS. AMER. MICROSC. SOC. 88(1): 142-148. 1969. This content downloaded from 157.55. 39.96 on Sun, 02 Oct 2016 06:14:59 UTC All use subject to http://about.jstor. org/terms