Acta Vet. Brno 2010, 79: 73-78
Efficacy Testing of Orally Administered Praziquantel to Common Carp Naturally Infected by Caryophyllidean Tapeworms (Platyhelminthes: Eucestoda)
The aim of the study was to assess the effects of orally applied praziquantel on the treatment efficacy against most abundant tapeworms (Atractolytocestus huronensis Anthony, 1958 and Khawia sinensis Hsü, 1935) of common carp (Cyprinus carpio Linnaeus). Naturally infected fish (1.5-year-old; K1-2) were divided into 6 groups. Three trial groups were administered praziquantel mixed in heat-treated amyloid vehicle (at doses of 50 mg kg-1 body weight). In 3 groups of control, the fish were administered amyloid vehicle only. Fish were examined using gut dissection 2, 4 and 6 days after the administration. The location, intensity and prevalence of individual species of tapeworms were recorded. A. huronensis and K. sinensis were found in the gut of carp together. A. huronensis was situated in the oesophageal part of foregut, and K. sinensis came after – immediately before the first intestine loop, of the intestines of carp. The invasion of A. huronensis was fully eliminated in all trial groups after 4 days whereas some specimens of K. sinensis still persisted in the gut of few fish. The full elimination of both parasites was observed 6 days after administration. Our results showed that elimination of K. sinensis takes longer than elimination of A. huronensis. The dose of 50 mg kg-1 of orally administered praziquantel is effectual to control A. huronensis and K. sinensis infections in common carp successfully, however, a significant decrease of the number of parasites was also caused by a single oral administration of big bolus vehicle and leaving unfed fish in the clean water.
