The above answer is grossly incorrect, not to mention poorly written.
The minimum age to breed a dog is 2 years, even if the dog has reached "puberty" before then. They will not die, of course if they are to become 'active', but a responsible breeder will not breed their dogs until the age of 2. The maximum age varies, depending on the breed and condition of the animal, not to exceed 10 years- 8 years of age being the standard. Again, taking part in sexual activity would not cause death in a healthy animal at any age.