A dog does not HAVE to be two years old to breed. There is no sudden magical transformation at this age that will reveal what your dog will produce genetically, physically or mentally, and it is not a magical age which any and all faults will suddenly be revealed. In dogs, some people choose to breed them younger, that is a personal descision. B*tches should not be bred as early because raising a litter pulls reserves they need for growth. HOWEVER, the longer you wait to breed a dog, the better. The more time you give a dog to develope an anomilie, so you don't have to look back, years later and go "darn" the better. Also, breeding *often* changes the behavior in a dog. Once this behavior is established, it is usually irreversible. Male dogs will begin urinating and deficating in your house to mark territory. This behavior can also be seen in bitches who have been left intact. Breeding makes a male more territorial, and his hormones levels will rage everytime something goes into heat, even if it is a mile away. If this dog is a PET and not a show dog, or an important stud dog in a breeding program, neuter him and enjoy him. Stud dogs RARELY make good pets.