Although much of the current standard of care in veterinary oncology is based on retrospective studies or transference from the human literature, a new era of clinical trial awareness brought on by new consortia and cooperative investigative groups is beginning to change this limitation. The use of controlled, randomized, blind multicenter trials testing new cytotoxics and cytostatic agents is now becoming the norm rather than the exception. Ultimately, advanced clinical trial design applied to companion animal populations should advance veterinary-based practice and inform future human clinical trials that may follow.