@HappyBanshee, I'm sorry, but at this time I don't know of a way to force any births to happen, especially for the bug that exists in the strays that prevent them from having offspring. ๐
We can either wait for EA to fix this, or we can look for a 3rd party fix. I don't play with CC or Mods anymore (caused too many problems with TS3, so I'm not even trying them in TS4), so I will have to wait for EA to fix this! ๐ค
The only other thing I can think of is to take your pet to the Vet an get him "fixed" and then a bit later take him back and get him unfixed. ๐ค Even if that works, it wouldn't solve the stuck pregnancy problem that you are currently having (and it might not work at all!) โน๏ธ
I was able to get 2 CAP generated dogs to successfully mate and give birth to 3 puppies, all of whom showed up in my game. So breeding does work with CAP created pets! ๐
In the meantime, there is a thread at the Sims 4 forum addressing this. It is constantly being added to, so I haven't read all of it. I don't think there are any workarounds at the moment. Seems we just have to wait on EA. ๐ข Here is the link:
http://forums.thesims.com/en_US/discussion/928960/cats-and-dogs-issues-with-breeding/p1
I will try some expierimenting and also look around some more for a work around, but don't hold your breath! ๐๐ If I find anything I will update you. And if you find anything, please update me! ๐