#4 – Great Dane
While Great Danes also suffer from other health issues that may shorten their lifespan, cancer is still the top killer of this giant breed. Osteosarcoma is the most common culprit.
#5 – Doberman Pinscher
Dobermans are especially prone to mammary cancer in females and prostate cancer in males. Spayed dogs are less likely to develop mammary cancer. Dobies are also prone to bone cancer.