I have two 4 yr old beautiful black dobbies. I have separated them around the time they went into heat for the first 3yrs. I was not looking for anything but what best for my pups. Now they are four and the past 2 time`s she went into heat, my male tried humping her, she got nasty and then vicious. I then seperated them. I tried it twice as i said just in case it was something else the first time, like she didnt feel good, or was just moody, idk. So my question is; Did i do something wrong by making them wait 3 yrs? Is it too late? And if so, should i just keep them seperated when she is in heat? I have spent time asking, reading, and researching. And you would not believe so of the advice i was given. I figured this would be my best bet. Please only serious replies, I dont want my pups hurting each other becuse i did something wrong. Also, I am not giving my dogs any type of drugs, shot or pill to calm her calm for mating. So please do not even waste your time with that advice. I am not looking to force breed my dobbies, my concern is their safety and puppies would obviously be gift.