Four separate controlled and blinded studies were conducted to confirm the dose of
spinosad and
milbemycin oxime (MO) administered orally in combination to dogs for the treatment and control of naturally acquired
infections of adult whipworm (Trichuris vulpis), hookworm (Ancylostoma caninum) and ascarids (Toxocara canis, Toxascaris leonina). Dogs were allocated randomly based on pre-treatment quantitative nematode egg counts of each species of interest to one of two treatment groups of 10 or 11 animals each. In each study,
spinosad and MO in combination, was given orally to dogs using the lower half (30-45 mg/kg
spinosad; 0.5-0.75 mg/kg MO) of the US commercial dose band (30-60 mg/kg
spinosad; 0.5-1.0mg/kg MO) of each active ingredient on Day 0 using a
tablet formulation. A corresponding vehicle control group was treated similarly in each individual study. Dogs were necropsied post-treatment on Day 7/8. All nematodes in the intestinal tract collected at necropsy were identified and counted by species and stage. The
spinosad and MO combination group demonstrated significantly different adult intestinal nematode efficacy in each individual study as compared to the vehicle control group. Efficacy values for whipworm, hookworm, T. canis and T. leonina were 100%, 99.8%, 100%, 93.3%, respectively. Minor non-serious adverse events were observed in a small number of control and treated dogs that were attributed primarily to the natural
nematode infections. In summary, flavored
spinosad and MO combination
tablets administered orally to dogs were both safe and highly efficacious delivering >93% up to 100% adult intestinal nematode control in naturally infected dogs.