I haven't had a problem with AI so far. One female (no testing) 2 AIs 7 pups. Another female (test) 2 AIs 9 pups. Is it a larger breed thing maybe? Or I should say certain breeds maybe? I know some species won't take AI, they have to go through the act. So wondered if some dog breeds might be less likely to take. My friend's large Pit was bred via AI and no pups.