The Sims 3 Pets Glitch.

Mmm, hello there.

Well... I have an in game glitch. I updated 2 of my mods up to the current version and have no custom content.
I have two dogs on the Sims 3, and they're up to "Mate" on their relationship.
What's funny though, they can't seem to mate. Every time I click on "Try For Baby!" on the dog house, the action always cancels no matter what.
I don't know what's wrong though? I've been having those 2 mods for a year now and they never cause' problems since the Modder always has the new versions on time and updated.
Only animals that seem to mate are the Horses and Unicorns. Other than that, no puppies or kittens. It's kind of sad in mine and my bestie's point of view. Hehe. :3