Ritchie, A., Collier, P., Clare, P. et al. 2019. Food for thought: The development of drug loaded diets improve both science and welfare. Animal Technology and Welfare 18(3), 222-224.

In our facility, we use several hormone dependent tumour models with supplementation delivered via slow release subcutaneously implanted pellets, implanted via trochar. For example, breast tumours which rely on 17-β-Estradiol. Administration of E2 supplementation can result in side effects such as bladder calculi and urine scald. Therefore, to improve animal welfare and to avoid steroid supply problems, we decided to develop a new way to provide hormone supplementation via the diet. Delivery of hormones via the diet is a major refinement in welfare terms by: reducing the need for an invasive implant and possible removal procedure; reducing deleterious side effects; promoting tumour growth; ease of delivery for the Animal Technologist. Similarly, our pilot therapy experiment demonstrates that delivery of drug therapies via diet rather than daily oral gavage is both a welfare improvement and potentially a translationally more accurate model.