van Wijk, H., Crossman, L., Adjin-Tettey, G. et al. 2018. Advances in animal welfare and scientific outcomes of the bile duct cannulated rat model utilised in ADME studies. Animal Technology and Welfare 17(1), 64-67.
Since rats lack a gall bladder, they are an ideal model for investigating continuous biliary excretion and biotransformation. The design and implementation of a modified tail cuff and cannula system introduced at Covance permits the animal's own bile to be re-routed back into the duodenum during the period following surgical cannulation and prior to dose administration. This innovation means that animals do not require tethring or single housing during this critical time frame, three to five days before initiation of the experimental sample collection. Surgical success rate, reduction in bodyweight losses, comparable animal health observations and acceptable excretory output and bile flow results all suggest that the PinPort model improves animal health and welfare without infringing scientific integrity. It also offers the opportunity to reduce the number of animals undergoing surgery to support metabolism studies. On this basis, the PinPort model has become the new standard for bile duct cannulation surgery at Covenance, Harrogate.