Things can get confusing, however, in cases of male dogs of the same breed. (dogcare.dailypuppy.com)
This condition, called azoospermia, affects approximately 1 percent of the male population and is responsible for about a sixth of cases of male infertility. (sciencedaily.com)
In case of male dog, you should measure forward to covers the urethra. (dogguidereviews.com)