I need help or I should say Donald needs help. My Donald is about 6 to 8 years old, male and his tail is dragging and white matter in one eye. I've been looking on line and I think he has a respiratory infection. My husband refuses to take him to a vet and I've tried contacting a vet nearby, I left a message but have not heard back. there isn't many here that will treat ducks. My husband went to Orschlen's and bought Terra-Vet 10, which is a Tetracycline Hydrochloride Soluble Powder without asking for help. I don't know if I can give it to him, or how much or how often. If anyone can help me please give me some advice, Thank you. I also have Adam a 12 year old goose with him in the backyard and he is fine.