Tolerance of adult zebrafish and efficacy of
emamectin benzoate and
ivermectin in eliminating Pseudocapillaria tomentosa
infection were evaluated. In the tolerance study, behavioral changes, fecundity, histopathology, and mortality were evaluated for in-feed administration of
emamectin (0.05, 0.10, and 0.25 mg/kg) and
ivermectin (0.05 and 0.10 mg/kg). All doses of
emamectin were well tolerated.
Ivermectin 0.05 mg/kg administration resulted in mild behavioral changes and a transient decrease in fecundity.
Ivermectin 0.10 mg/kg administration resulted in severe behavioral changes and some mortality. In the efficacy study,
emamectin (0.05 and 0.25 mg/kg) and
ivermectin (0.05 mg/kg) were evaluated for their efficacy in eliminating P. tomentosa
infection.
Emamectin reduced parasite burden in infected zebrafish, and
ivermectin eliminated intestinal
nematode infections. Despite a small margin of safety,
ivermectin 0.05 mg/kg was effective at eliminating P. tomentosa
infection in adult zebrafish. Higher doses or a longer course of treatment may be needed for complete elimination of P. tomentosa
infection using
emamectin. In this study, we propose two possible treatments for intestinal
nematode infections in zebrafish.