fish wont open its mouth

Question
Hi there, my fish is a large ordinary goldfish. He has become lethargic, and can't open his mouth. His tail is also hanging slightly scew. He is with another goldfish and this fish seems fine. He can't eat and spends most of the time sitting on the bottom of the tank. I scooped him out in just enough water to keep him covered and then gently with a Q tip tried to open his mouth but it wouldn't move and I was quite nervous of hurting him. I've tried water balance drops . I'm worried he's going to starve to death. What can I do to try and help him.
Thanks for any help.
Regards
Jade

Answer
Jade,                                                        It sounds like your ammonia is very high. I would test for that. Goldies are very dirty fish, though beautiful. If your goldies are big and your tank is small that is probably the problem.If not it is probably a swimmbladder infection. You should add some maracyn-tc if your ammonia is ok. It is a broad spectrum antibiotic. Treat for 7 days and don't forget toi remove your carbon . After do a 25% water change.To prevent swimbladder infection in the future... sqeeze a frozen pea between your fingers and feed it to them. Whatever is left of it in an hour or two take it out. You can also give them a half slice of orange once a week for vitamin c. They will love you for it.Get a veggie clip from your local petshop to hold it. Good Luck,Tina