OMG,reading this made me cry!! It took me back a few years when exactly the same thing happened!! We didn't really know much about dogs at the time but had decided on a yorkie for many reasons. So we searched for a reputable breeder and eventually found our pup who we named Roxy.She was such a precious little thing, and she was only 6 weeks old, which at the time we thought was ok becuase alot of puppies were being sold at that age and the breeder had assured us that was normal. So we hesitantly took her and enjoyed the 2 days we had with her.It came to a very tragic end on the third day when we were woken by a very load coughing screaming sound.It was heart braking because it sounded like she was in tremendous pain.I was a shaking crying mess,but my hubby took her to the vet whilst i anxiously waited at home.They had to put her down about 5 minutes after she got to the vet.It was suspected she contracted Parvo. She just didn't stand a chance at life and it makes me so angry that this poor little thing was exposed to such a dreadful virus. I cannot believe people are selling these innocent angels to people so young, and it should be illegal.
If I was your friend , I would definately be taking action! Thats exactly what we did. We had our vet write up a report on the cause of death which was dated and signed, then sent to the breeder. We were given a refund, but I will never get over what happened to Roxy. I also warned other people to avoid this breeder and advise your friend to do the same.