Jack of Jack and Diane was one of a couple of puppymill Rat Terrier/Chihuahua mixes that we got back in the spring.  They were in very poor shape, emaciated and had skin issues.  Jack had heartworms, but Diane did not and she found a home very quickly.  We considered keeping them together, but they seemed to be fine separated as long as they had a doggy friend.  Jack has since been treated for heartworms and put on some (a little too much) pounds.  He is a very sweet little guy.  He is up-to-dated on vaccinations and neutered.  We will do a dental before letting him go.