Efficacy of a novel chewable tablet (Credelio Quattro™) containing lotilaner, moxidectin, praziquantel, and pyrantel for the treatment and control of hookworm infections in dogs

Background: Hookworms, specifically Ancylostoma caninum and Uncinaria stenocephala, have a clinical impact on the health of dogs, with A. caninum posing a zoonotic risk worldwide. The studies presented here were conducted to evaluate the efficacy of a novel, oral chewable tablet (Credelio Quattro) containing lotilaner, moxidectin, praziquantel, and pyrantel (as pamoate salt) against fourth-stage larvae (L₄), immature adult, and adult A. caninum, as well as adult U. stenocephala, infections in dogs. Methods: Nine negatively controlled, masked, randomized laboratory studies evaluated the efficacy and non-interference of the drugs against various stages of A. caninum and U. stenocephala. In addition to one pilot study conducted against L₄A. caninum and one study that assessed efficacy in dogs with naturally acquired U. stenocephala, two experimental studies were conducted against each of the target hookworm species and stages. A total of 16–31 dogs comprised each study. With the exception of the study in dogs with naturally acquired U. stenocephala, dogs were experimentally infected with the target parasite and dosed on Day 0 or 4 with placebo tablets, Credelio Quattro tablets (or components of Credelio Quattro formulation for the pilot study), or individual actives, moxidectin or pyrantel, in the specific studies designed to assess interference. Efficacy was evaluated by comparing the number of worms recovered at necropsy 5–10 days post-treatment between the treated and control groups. Results: All dogs tolerated Credelio Quattro well. Efficacy of Credelio Quattro was ≥ 99.0% against L₄A. caninum, ≥ 99.8% against immature adult A. caninum, ≥ 99.9% against adult A. caninum, and ≥ 99.6% against adult U. stenocephala. Additionally, treatment with Credelio Quattro provided a ≥ 99.9% reduction in fecal egg counts 10 days post-treatment. Conclusions: Credelio Quattro, a novel oral chewable tablet administered at the minimum effective dosages of 20 mg/kg lotilaner, 0.02 mg/kg moxidectin, 5.0 mg/kg praziquantel, and 5.0 mg/kg pyrantel (as pamoate salt), was safe and effective for the treatment and control of L₄, immature adult, and adult stages of A. caninum and adult U. stenocephala in dogs.