Cancer is the leading cause of death in dogs over 10 years, yet most cases are diagnosed at late stages. Emerging liquid biopsy technology and improved owner awareness can shift diagnosis to more treatable early stages.
Cancer welfare in dogs encompasses both the suffering caused by disease and the distress of treatment. Late-stage cancer diagnosis denies dogs the option of curative treatment when earlier detection would have made surgery, chemotherapy, or radiation effective. Regular preventive screening in high-risk breeds and annual comprehensive examinations increase the likelihood of detection at treatable stages. The welfare trade-off in cancer treatment is real - chemotherapy in dogs causes side effects including nausea, lethargy, and immune suppression. However, canine chemotherapy protocols are typically lower-intensity than human protocols, and most dogs tolerate treatment reasonably well. Quality of life assessment during treatment is essential to ensure that the treatment burden does not exceed benefit.