8 week old Kitten no interest in food!

Hi everyone!

We just got a new kitten a few days ago. He has no interest in food at all. He is very active and seems happy, but he barely eats. We have tried food wtih strong smell, tuna, liver, kitten powdered milk. The doctor said he could have a cold and gave antibiotic, but he needs food in order for it not to upset his stomach. Any advice would be greatly appreciative!!