While this virus can spread between cats, it cannot be passed on from a cat to a dog or to a human.Can cancer be treated in cats and dogs?Similarly to humans, cancer is the leading cause of death among older cats and dogs, and accounts for approximately 50% of deaths each year.hat is cancer?Cancer refers to a group of diseases in which abnormal cells (the structural and functional units of all living organisms) grow without control, invade surrounding tissues and ultimately spread to other organs throughout the body.