A comparison of the efficacy of two ivermectin formulations against larval and adult Ascaris suum and Oesophagostomum dentatum in experimentally infected pigs.
A study was conducted to evaluate and compare the efficacy of two injectable formulations of ivermectin (IVM-1 and IVM-2) at a dose rate of 0.3 mg/kg bodyweight versus placebo in the treatment and control of larval and adult stages of Ascaris suum and Oesophagostomum spp. in experimentally infected pigs. Seventy helminth free pigs were allocated on a liveweight basis to 7 groups each comprising 10 pigs (A-G). Group A served as an untreated control group. Groups B and C were used to investigate the efficacy of both formulations against adult stages of A. suum and Oesophagostomum spp., Groups D and E for efficacy against larval stages of A. suum and Groups F and G for efficacy against larval stages of Oesophagostomum spp. Pigs of groups A, B, C, D and E were infected on Day-0 with 1000 infective A. suum eggs each. Infective larvae of Oesophagostomum spp. (10,000/pig) were given on Day-0 to pigs of Groups F and G and on Day-21 to pigs of Groups A, B and C. Treatment was given to pigs of Group A (saline as placebo) on Day-7 and -28, IVM-1 to pigs of Group F on Day-7, pigs of Group D on Day-14 and pigs of Group B on Day-49. IVM-2 was given to pigs of Group G on Day-7, Group E on Day-28 and Group C on Day-49. Pigs of Groups F and G were sacrificed on Day-28, pigs of Groups A, D and E on Day-49 and pigs of Groups B and C on Day-56. Post mortem worm counts showed the following efficacies: (IVM-1) against larval A. suum 100%, against adult A. suum 94.4%, against larval Oesophagostomum spp. 52.0% and against adult Oesophagostomum spp. 83.0%. (IVM-2) against larval A. suum 100%, against adult A. suum 90.3%, against larval Oesophagostomum spp. 94.0% and against adult Oesophagostomum spp. 94.7%.
Borgsteede
F H M
FH
Animal Sciences Group WUR, Division Infectious Diseases, P.O. Box 65, 8200 AB Lelystad, The Netherlands. fred.borgsteede@wur.nl
Gaasenbeek
C P H
CP
Nicoll
S
S
Domangue
R J
RJ
Abbott
E M
EM
D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D001196:Ascariasis / Q000188:drug therapy / Q000662:veterinary*; D017165:Ascaris suum / Q000187:drug effects*; D005260:Female; D007559:Ivermectin / Q000008:administration & dosage / Q000627:therapeutic use*; D007814:Larva / Q000187:drug effects; D008297:Male; D009814:Oesophagostomiasis / Q000188:drug therapy / Q000662:veterinary*; D009815:Oesophagostomum / Q000187:drug effects*; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000469:parasitology; D013810:Therapeutic Equivalency
D000871:Anthelmintics; D007559:Ivermectin