Abstract
BACKGROUND: While generally harmless to dogs, the cestode species Echinococcus granulosus and Echinococcus multilocularis have significant zoonotic importance, causing cystic echinococcosis and alveolar echinococcosis in humans, respectively. Regular deworming is essential to treat intestinal cestode infections in dogs and to reduce environmental egg contamination and thus the subsequent zoonotic risk of infection to intermediate hosts and humans. The studies described here evaluated the efficacy of a new novel chewable tablet combination containing lotilaner, moxidectin, praziquantel and pyrantel (Credelio Quattro, Elanco Animal Health) against E. granulosus and E. multilocularis infections in dogs. METHODS: Four negative-controlled, masked, randomized laboratory studies were conducted. Two studies each evaluated the efficacy of Credelio Quattro at the minimum dosages of 20.0 mg/kg lotilaner, 0.02 mg/kg moxidectin, 5.0 mg/kg praziquantel and 5.0 mg/kg pyrantel against E. granulosus (Studies 1 and 2) and E. multilocularis (Studies 3 and 4). Studies 2 and 4 also included treatment groups that received praziquantel alone or lotilaner alone, at the same minimum dosages, to assess whether lotilaner, moxidectin or pyrantel interfered with the activity of praziquantel in Credelio Quattro against these two cestode species. In Studies 1 and 3, 16 purpose-bred dogs were divided into two groups of eight, while in Studies 2 and 4, 32 dogs were divided into four groups of eight. Dogs were experimentally inoculated with protoscolices on Day - 28 for E. granulosus studies and on Day - 18 or - 20 for E. multilocularis studies. Credelio Quattro, placebo, praziquantel, or lotilaner tablets were administered orally at the lower half of the dosage range on Day 0. Efficacy was calculated based on the number of worms recovered at necropsy, 4 or 5 days post-treatment, in the treated group compared to the control. RESULTS: Credelio Quattro was well tolerated in all dogs. Based on geometric mean worm counts, Credelio Quattro was 100% effective against both E. granulosus and E. multilocularis. CONCLUSIONS: Credelio Quattro administered once orally at the minimum dosages of 20 mg/kg of lotilaner, 0.02 mg/kg of moxidectin, 5.0 mg/kg of praziquantel and 5.0 mg/kg of pyrantel was safe and effective for the treatment and control of adult E. granulosus and E. multilocularis in dogs.