Efficacy of a therapeutic bath with selected antiparasitic drugs on a Dactylogyrus anchoratus infection in juvenile common carp (Cyprinus carpio)

The study aimed to assess the effects of a therapeutic bath of five different antiparasitic drugs, in different baths and durations: fenbendazole (25 mg l-1, 12 h and 2 × 12 h), formaldehyde (0.17 ml l-1, 15 min), ivermectin (0.031 mg l-1, 1 h), mebendazole (1 mg l-1, 12 h) and levamisole (50 mg l-1, 2 h and 3 × 1 h) on the reduction on the intensity and prevalence of a monogenean infection (Dactylogyrus anchoratus) in juvenile carp. The best effect on reducing the parasite number was achieved with the bath in formaldehyde (0.17 ml l-1, 15 min) and fenbendazole (25 mg l-1, 2 × 12 h with 24 h break), where the infection was reduced by more than 90%. Registered veterinary medicinal products (VMPs) with the active substance of fenbendazole can successfully replace the use of unregistered formaldehyde in the treatment of monogenean infections.