Welcome to YorkieTalk, Oscar's Mom!! The day we brought Toto home, she and her other littermates were all checked for Coccidia and she was the only one who didn't have it. She was 16 weeks old and weighed 1 lb. 8 ozs. and like your Oscar she was a tiny bundle of energy ... we were scared to death of her!!
We saw the vet three times that week and it was only the last visit that she showed that she also had it so it's a good idea to have them checked often. There were no symptoms that we could see ... I just make it a practice to have her little stool checked once a month when she sees the vet! She also was given Albon ... 2cc for fourteen days. Our vet gave us syringes with the doses already measured out! "Dr. Lucy" is wonderful [and very patient with us ... "over-protective" moms & dads]!
I have her on "speed-dial" at the office and at home and she doesn't mind at all getting "panic" calls! I think the most important thing for any Yorkie owner is a knowledgable vet!
BTW ... I noticed that you are also from Alabama! Where do you live? Our home is in east central Alabama!