His mom was a Chihuahua and his dad was a Chihuahua mix. He looks identical to his dad. But I'm starting to wonder if he's got mini fox terrier in him. The pics of mini foxies look very similar. Please help if you can!

He does look very Fox Terrier like, especially that face, and the markings.

Unfrortunately you will never know for sure, but I would introduce him as a Chihuahua X Fox Terrier.

I don't know. I might wonder about Jack (Parsons) Russell. Jack Chi, Jack Chis, Chihuahua Jack Russell Hybrid Dogs

He is a cutie no matter what mom and dad are. :)