Cancer registration in dogs and cats: A narrative review of history, current status, and standardization efforts

Cancer severely affects the health of companion animals, with neoplasia being a leading cause of death in pets. Although pets and humans share the home environment and dogs and cats can serve as sentinel species for environmental carcinogens, cancer surveillance in pets remains fragmented after decades of studies. The aim of this narrative review is to assess the evolution and current status of animal cancer registries (ACRs), highlighting historical milestones and key methodologies with a global perspective. The different types of cancer registries, their different roles and related issues in cancer surveillance are highlighted. Inconsistent diagnostic criteria, limited standardization, and lack of centralized databases hinder the comparability of results in veterinary oncology. Recent initiatives, such as the Global Initiative for Veterinary Cancer Surveillance (GIVCS) and the Veterinary Cancer Guidelines and Protocols (VCGP), seek to standardize cancer reporting and coding systems and promote a One Health approach that links veterinary and human oncology research. Increased standardization and data sharing between databases is critical to advancing cancer surveillance in companion animals, benefiting both veterinary and public health.