Bubble-Eye Goldfish Has Discolored Sac

Question
How long has your tank been set up? - Around 6 months
How big is your tank? - 30 gallons
What type of fish? - Bubble-Eye Goldfish
How many fish do you have? - 4
Type of filter? - Cascade 300 Power Filter
What are the pH, ammonia, nitrite levels? - pH: 7.2, ammonia: 0-.25, nitrite: 0
How often do you change water? Once a week
How many gallons of water are replaced every time? Around 20-25

I have had my largest bubble-eye for years and years now. Throughout most of his life, his right bubble sac would turn red, as if filled with blood. I would then treat him with Amoxicillin and always went away. However, this time it did not work. I then tried T.C. Tetracycline, which also had no effect. I then went to medicated food and purchased Medi-Gold. Still no change. His bubble has been like this for months now. It is really worrying me. He is still swimming and eating fine, however during the past month his bubble sacs seem to have become looser and floppier, for lack of better words. It looks as though they may have deflated just a little. I have debated pin-pricking his right bubble sac and draining it, but am afraid to take any action without advice from someone who may be able to help. His cheek has been like this for so long, it has turned darker, as if the blood inside (if that is what it is) is old. I appreciate any advice you can give me. Thanks much.

Answer
Hi Shannon;

He may be injuring himself or rubbing it on something and causing irritation. I have never opened one to allow draining so I really can't advise on that. It may not help and it could allow more infectious pathogens inside there. Or, it could release pathogens out in the tank water that could infect the other fish. The infection may still be lurking in there. If the infection were gone I would think his body would most likely absorb the blood/fluid and look more healthy and clear up. Here are some other thoughts and suggestions I have;

If there are any plants or other decorations that are not rounded or soft on the edges, remove them and see if he improves. Some fish have habits of movement or areas they like to rest at night that cause them trouble.

If your tank has a heater, be sure he can't get close to it. Some fish like to hang close and they can get burned. Put decorations close or get a heater guard.

Try changing his diet to include more veggies. Goldfish are mostly vegetarian and the processed foods we buy for them usually have too much protein and not enough fiber. A plugged up digestive system can compromise the immune system. I feed cooked peeled green peas, cucumber slices, cooked green beans, cooked shredded carrots, and romaine lettuce. Frozen brine shrimp is good too, but not daily or it's too much protein. The tiny exoskeletons of brine shrimp are like little "scrubbers" for the intestines. These foods all help with color too, naturally increasing the intensity of red and orange over a period of 3 to 4 weeks.

Be sure to vacuum the gravel every week when you change water in the tank. Sometimes fish will get close enough to dirty spots in the gravel that they develop infections and irritations from the toxins there.

If you can get a smaller tank to use as a hospital tank, maybe ten gallons or so, you could isolate him for serious treatment. I've even put them on the floor somewhere or in the bathroom if there is no room anywhere else. When we add medicine to our established tanks the medication strength is lessened greatly from filtration, waste in the gravel, and decorations. Those things will all "absorb" the medication to a certain degree. If we use a bare hospital/isolation tank it gives the advantage of making most of the medication available to the fish. Your hospital tank should not have a filter but it needs air. Get a little air pump and an air stone for it. Don't add any gravel or decorations. You will need to change part of the water every day. Replace 25% to 50% daily right before that day's addition of medicine. I would try a tetracycline product. There are many available. Tetracycline is a broad-spectrum antibiotic that may just nail this thing if he is isolated. Aquarium salt and a product called Melafix could be helpful too. Salt can restore electrolytes and inhibit infection. Melafix helps regenerate damaged tissues and helps inhibit infection too.

I hope he feels better very soon. Let me know how it's going...

At Your Service;
Chris Robbins