My yorkie is shaking like having chills i already took to vet and they gave antibiotic but still not eating? They took blood and said he was a bit anemic. I am feeding him with a syringe. He wont eat anything on his own

It takes several days for the antibiotic to have a full effect. In the meantime, keep the dog warm and continue to give as much food and especially water as you can. Follow your doctors instructions and if you still have any questions call him and ask. You are paying the doctor, so get your money's worth.