It is widely agreed that cancer is a significant problem in veterinary medicine; a commonly quoted statistic is that one in four dogs will die of cancer. It has long been known that the immune system plays a role in the development and control of cancer, and antibody-based therapies have been very successful oncology drugs for many years. However, the recent human clinical successes of oncology therapies that engage elements of the host immune system to fight cancer have emphasized the importance of immuno-oncology. This talk gives a brief summary of the current status of vet oncology – what are the most common veterinary cancers, how are they currently treated? Those treatments now also include a number of veterinary-specific agents that be can be classified within the ‘immuno-oncology’ category. Finally, what can be learned and leveraged from the human health experience with this category of drugs, and what might we see next in veterinary oncology?