Spontaneous tumours of pet dog as models for human cancers: searching for adequate guidelines.

Despite the ongoing search for "replacement" alternatives, animal models continue to play a crucial role in bio-medical research. However, both in vivo and in vitro models usually employed, such as rodents and/or cell lines, display intrinsic limits related to the specific characteristics of the biological systems used, whose management is very complex, and whose pathology, usually induced under artificial laboratory conditions, is frequently dissimilar to the studied human spontaneous disease. It has been suggested that carrying out clinical trials based on pre-clinical data obtained after a screening on animal models developing the neoplastic disease in a more similar way to human beings, as represented by spontaneous canine tumours, could accelerate the entry of new effective drugs into the clinical practice. In this paper the authors discuss the scientific foundation as well as the ethic and legal concerns related to the use of this "pet model" in comparative oncology, suggesting some "key words" as the necessary starting point for a correct approach to the matter.