Long-term safety of Credelio Quattro chewable tablets for dogs

Abstract

BACKGROUND: The combination of lotilaner, moxidectin, praziquantel, and pyrantel pamoate (Credelio Quattro) is a novel systemic endectocide that provides month-long effectiveness in dogs after a single oral treatment. The safety of Credelio Quattro flavored chewable tablets was investigated when administered orally at the upper end of the recommended dosage range (20-41 mg/kg lotilaner, 0.02-0.04 mg/kg moxidectin, 5-10 mg/kg praziquantel, and 5-10 mg/kg pyrantel) and multiples thereof when administered long term. METHODS: The study was randomized and blinded, with parallel groups beginning in healthy 8-week-old Beagle dogs and continuing until they reached adulthood. A total of 32 dogs were randomized among four groups (8 dogs/group) to nontreated controls or to treated groups at target doses of 1×, 3×, or 5× the maximum dose. Treatment was administered on nine occasions to dogs in a fed state every 4 weeks, with the control group receiving placebo tablets. Assessment of safety was based on regular health observations, complete physical/neurological examinations, food consumption, clinical pathology evaluations (hematology, clinical chemistry, and urinalysis), body weight, and macroscopic and microscopic examinations of collected tissues. RESULTS: Credelio Quattro did not induce any serious treatment-related adverse effects based on health observations, physical/neurological examinations, food consumption, clinical pathology, body weight, or macroscopic and microscopic examinations. The only non-serious treatment-related effects of Credelio Quattro were a dose-dependent increase in the frequency of discolored feces, diarrhea, and vomiting (including hypersalivation associated with vomiting in two of the 5× dogs). CONCLUSIONS: This study demonstrates that Credelio Quattro exhibits a wide safety margin when administered monthly to puppies and dogs at the maximum recommended commercial dose, with only transient gastrointestinal symptoms similar to other oral antiparasitic products observed. Therefore, Credelio Quattro may be safely administered to dogs each month in accordance with the approved label.