Yes I would if the bird is an adult it will get the adult dosage whether it lost weight or not. You also need to understand if you google the antibiotic you will see that there is a large gap before you can actually over dose on the antibiotic. For example I read online with baytril it took 500 cc/ml to over dose an adult rat, granted I feel so sorry for that rat but someone did do it. Giving and adult bird 1cc will not kill it. If your doctor gives you a Z Pack for an upper respiratory infection it's one size fits all cause I asked. I weigh 210 pounds and you weigh a lot less but yet it is the same dose and we take 2 pills the first day and then 1 a day. My dog had an infection and the vet gave it a 3 day shot of antibiotic and then gave me pills to start on the 4th day. My dog wasn't over dosed. It is better to give a little more then a little less.