A. Accidents

B. Obesity

C. Cancer

D. Organ issues

Details About Why do small dogs live longer:

Dogs live an average of 13 years, although size counts; large dogs survive just 8–12 years on average, whereas smaller canines live 14–18 years. The main cause of this is lower cancer risks, as huge dogs often develop quickly—many of them can acquire 100 pounds in a year at a young age. It is thought that later in life, cell proliferation leads to cancer and other problems.