He is 3 mos old. Has been eating medicated chick starter. Now he is droopy and hunched up. May have some watery stools His tail feathers looked somewhat wet. I just dewormed him with Safeguard. I had also dewormed him last month. I have : tetracycline powder, amoxicillin, and metronidazole 250mg Tablets for dogs. Can I use any of these.?