Pets hybrid and puppy mod

Hello everyone! What I try to do for some time is to hybridize with large dogs small dogs in Sims 2! What I could do is this: if you change with simpe species list, a dog large with a small dog, the coupling will result in dogs genticamente hybridized with Aspetos species of choice for the couple, (dog large or small dog), but the animation of the animal changed, and his voice will not be realistic! I do not know how to remedy that problem. I'm not a programmer and I can not understand what else should be changed ...

Another request, perhaps more simple, would be a change the number of animals that are born at the maximum one two puppies, and not three or four. It 'nice to have puppies but after a while they become too much, and I'm not going to give them up for adoption ...

If he had not understood are an animal lover:-)

I sincerely thank those who would know help me!