Objective: Pain, distress, or discomfort should be minimized during experimental procedures using animals. The goal of this work was to establish humane endpoints for a model of bladder cancer chemically-induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN).
Methods: Procedures were made in accordance with the European Directive 2010/63/EU. Twelve Wistar rats were used. The carcinogen agent BBN was administered in drinking water during 20 weeks. After this, they consumed only water until 35 weeks of the experimental protocol. During the protocol was used a scoring sheet where biological variables were registered daily to monitor animal welfare.
Results: No animals died during the experimental protocol. Four animals showed signs of haematuria since the fifteenth week after the beginning of the experiment, these animals also exhibited moderate anemia in the last week of the protocol that was evident through the mucosal observations. All animals exhibited a mental status, eyes, ears and whiskers position, response to handling, breathing and hydration within the parameters considered normal for the specie.
Conclusion: The animals did not show clinical signs compatible to suffering that justified their sacrifice before the end of the study. The endpoints established for this model are adequate to bladder cancer studies once no endpoints were reached.FCT (PTDC/DES/114122/2009) and CI&DETS (PEst-OE/CED/UI4016
