The recent development of small-animal imaging hardware has provided functional imaging researchers with extraordinary tools for preclinical studies. However, radiation oncology studies, either tumor response or normal organ response, has been hampered by the lack of a tool for the precise irradiation of small animals. A conformal small animal irradiator based on teletherapy is proposed. The irradiator is based on a small, high-activity 192Ir source. Measurement-validated Monte Carlo dose distribution simulations have been conducted to aid in the optimization of the irradiator design. Adequate dose rates (in excess of 1 Gy min-1) are shown to be possible with adequately steep penumbra and low irradiation levels outside the irradiated fields. We are currently designing and building a prototype system.