What would be a reason why my mini chihuahua can't get pregnant?

You are much better off with your chihuahua not being able to get pregnant. So many tiny chihuahuas die while giving birth. Most likely, you are not an informed breeder and will run into many genetic, birthing and weaning problems with lack of knowledge and research. We have such a big pet overpopulation problem in the country, why add to it? I think it’s a blessing in disguise that you can’t breed your chihuahua. Instead of asking why your dog can’t get pregnant, maybe now you can focus on asking how you can give her the best care and love she deserves for the rest of her life without turning her into a breeding machine, taking away her puppies, and continuing the cycle again with another irresponsible person.

That’s a pretty general question, but I think the other two posters gave some good answers.

It could be that one or both of the dogs are too young. They should be 8 - 10 months old. There could be something physically wrong with either one of them. They may not have mated. They should tie together and stay that way for several minutes. Also, it might be too soon. My Chihuahua did not show any signs of being pregnant for about five weeks. The puppies should be born in the 9th week.

infertility