Amoebic gill disease (AGD) is a devastating disease that causes multi-million-dollar losses annually in salmonid fish farming. The causative agent of AGD in Atlantic Salmon is Neoparamoeba perurans which belongs to the Paramoebidae family. An interesting feature of most of the Paramoebidae is the endosymbiotic relationship they have with the Perkinsela-like organism (PLO). The PLO is a kinetoplastid, distantly related to diseases causing parasites in humans such as Leishmania and Trypanosoma spp. and fish diseases such as Ichthyobodo spp. As there appears to be a high level of metabolic interdependence between host and the symbiont, eliminating the PLO, which resides adjacent to the nucleus of its host, will hypothetically eliminate N. perurans . In pursuit of this goal, we have opted to utilise frontline and experimental trypanocidal drugs targeting the PLO both in vitro and in vivo . As N. perurans cannot be cultivated axenically, conventional drug screening methods face hindrance due to bacterial activity within the amoebic culture. To assess in vitro efficacy, holographic microscopy was utilised to evaluate cell motility and viability under drug pressure . Drugs demonstrating promising in vitro efficacy (figure 1) were subsequently tested in two rounds of in vivo trials on the West Coast of Ireland which had exhibited encouraging signs of effectiveness (figure 2) . It is anticipated that establishing a market for trypanocidal drugs in aquaculture could enhance fish welfare and potentially reduce production costs for the application of these drugs in a medical context within the tropics.