
Unless you have the facility to seperate them when the bitch is in season, then you should not consider geting him a bitch companion.
As for breeding, how will you know if he will be the best suited mate for her? You will have noo idea how she will turn out, ajnd as yet no idea how your boy will finish up. The only good reason to breed is to improve maintain the quality of the breed.
You would only wish to take one or two litters from your pair, so what are you going to do the rest of the time when she comes in season. bitches do not have a menopause. Even if you have her spayed after bree3ding, you will have to keep them apart for probably 5 consecutive seasons, as a Rottie should be around 2 1/2 to 3 years at lest before being bred from.
By all meand get a companion for him, but wait until he is two or 3 years old and well trained, anjd have one or other neutered.