I'm glad you got her to the vet, I have learned quite a bit about the Giardia. It is a killer of puppies if not caught. And the saddest thing is that it is simple to cure. I thought I got my pup from a home raised breeder, but later found out NOT! The lady, Rita, is actually a broker. My husband called her and she is in denial of everything, so I have to try to contact the breeder via the address on the papers I guess. Mother dogs can be carriers of it and she will need to know that she needs to keep an eye on her pups, after all, pups, once bred are the breeders responsibility for life, that is if you are reputable, from all the paper work I have read yet and that part of that responsibility includes taking responsibility for the health and wellness of those pups. It also entails taking back genetically and physically imperfect or carriers of severe recessive genes and either raising them for the rest of their lives or having the heart to put them to rest, also taking responsibility to deny breeding rights of recessive traits like bad knees. I found this stuff out by the AKC site and sites they suggested via the paperwork I received with my dogs papers. Also through a breeder my sister talks to. I don't think I would ever want to breed. Phoebe is my heart and I would not give her back. I am so glad you caught it and was able to start a resolution of your baby's sickness.
