Cancer is a major cause of death in older dogs and treatment is often ineffective. Genetic (heritable) factors are important in development of Transitional cell carcinoma (TCC) of the bladder. The Scottish and West Highland White terriers and the Shetland sheepdog are at high risk for TCC, and a subset of dogs of each breed are born with errors in critical genes that predispose them to the disease. Using these breeds as models for genetic risk, Dr. Ostrander will narrow in on two regions of the genome where error-prone genes were discovered and identify the mutation as well as fine map the remaining critical gene. Methods developed in this effort will translate to other cancers and thus have the potential to help dogs of many breeds.