I'm sorry you went thru this after you boarded your dog. It is upsetting when one picks up their animal at a facility that they have put their trust in because their pet is 'family'.
This summer we boarded our Yorkie and had a similar thing happen but our dog ended up getting sick a day after he came home from the kennel. He had bloody diarrhea, didn't eat or drink anything or even want a dog treat. We knew then something was wrong. He didn't even want to lay on our laps. So I immediately called the vet for an appointment. The vet told me it was some form of colitis that is from being boarded in a kennel (from stress). He says that he sees it a lot and that some animals get it when they are boarded every single time; some not. It just depends on the animal.
It is sad your dog and you/your family went thru what you did with the facility. It was uncalled for and along with the person who posted. Only a professional veterinary should diagnosis an animal for an illness; period. That is why they are 'considered a veterinary' and have their degree. You have every right to feel angry.
I hope that your Yorkie is feeling better and that the doggie heals soon. Animals are very much a part of our lives. They are such a great part of our families. That is why you are beyond hurt by this incident.
((HUGS))
Coopers Mommy