Pheochromocytoma (PCC) is a catecholamine-secreting tumor originating from the adrenal gland. It is an emerging diagnosis in dogs, and currently, no medical treatment is available. This study will uncover the molecular signature of canine PCC and search for novel theranostic options. We will perform RNA sequencing to detect canine PCC transcriptomic profile(s) and whole-genome sequencing to identify the mutational status of these tumors. Both techniques will also be applied on organoids and tumoroids, which will be cultured from canine normal adrenal medullas and PCCs, respectively. These data will enable us to identify novel radioligands and radiotherapeutics that could lead to the future theranostic approach of canine PCC. Furthermore, the study will give the direction for potential medical treatment options. This project is an important step in veterinary medicine but will also provide a roadmap of translational research targets and will position the dog as an animal model of PCC in one medicine approach.