The monogene Decacotyle floridana is found on the skin and gills of spotted eagle rays (Aetobatus narinari), and has caused morbidity and mortality in this species in aquaria. Praziquantel bath treatment has been used to control monogene loads in eagle rays but treatment can be labor- and time-intensive, particularly with larger rays or repeated therapy. Oral praziquantel therapy would allow better targeting of affected individuals and tissues, more effective reduction of parasite loads, and potential reduction in the frequency of handling and stress to the animals. Exact oral praziquantel pharmacokinetics in eagle rays, however, are unknown.
The purpose of the current study was to determine the blood concentrations of praziquantel after single oral administration of 100 mg/kg praziquantel via gavage to eagle rays. Eagle rays' blood was collected every other day post treatment over a 14 day period. One ray started blood collections on day 1 post oral praziquantel administration, and two rays started on day 2 post oral praziquantel administration. Plasma samples were analyzed with high performance liquid chromatography (HPLC) to determine the praziquantel concentrations at each time point. This study will help us better understand the pharmacokinetics of this drug in spotted eagle rays, so that we can more effectively target treatment of Decacotyle.
The authors thank the Disney Aquarium, Science, Water Science, and Animal Health teams for their support and assistance with this project.
* Presenting author