Neutering reduces the incidence of which cancer in male dogs?

• A. Brain cancer.
• B. Prostate cancer.
• C. Liver cancer.
• D. Skin cancer.

Answer: (B)

When a male dog is neutered, testosterone levels drop dramatically. The prostate gland grows and stays active largely under the influence of testosterone. With less hormonal stimulation, the prostate tends to shrink and is less prone to diseases that can progress to cancer. This hormonal change is why neutering is associated with a lower risk of prostate cancer in male dogs.

The other cancers listed—brain, liver, and skin—aren’t driven in the same way by testicular hormones, so neutering doesn’t have the same protective effect for them.