goldfish swimming sideways and not eating

Question
Chris,
I've had my goldfish for about 6 years and it has grown to be almost a foot long. She is in a 50 gallon tank. We used to have other fish several years ago... She is now our only fish and recently has stopped eating and is swimming sideways. Her belly looks a little pouched out on her right side too. We took a sample of our water to a local pet store and they said our nitrites were a little high. We took out 25% water and are going to bring another water sample tomorrow to recheck. It has been a while since we last changed the water and plan to do it more regularly now. I'm concerned the fish my be constipated or just getting old. Once we get the nitrite level back to normal how long will the fish swim sideways approximately? Is there anything else we should do with these symptoms? Thanks so much for your help!

Answer
Hi Kim;

Hopefully she will return to normal once the nitrites are down. Make the water changes daily until it is under control. If the situation seems very bad, it's even okay to change 50% daily instead of just 25%. Just be sure to use a water conditioner and make sure the new water is the same temperature as the old water. Vacuum the gravel too. The cause of high nitrite or ammonia in an established tank is often from dirty gravel.

Something that will help her tolerate the nitrite until it goes down is a dose of aquarium salt. Nitrite poisoning changes the blood and prevents it from carrying oxygen as it should. The aquarium salt helps counteract this effect. Add 1/2 teaspoon of salt per gallon. Add extra aeration to help raise the oxygen levels too. Bubbles from an air stone hooked to an air pump is how to do that.

As for the bulge in her side, it's possible she has an intestinal blockage. Constipation is the main cause but there are other things too. Infection, tumors, swallowing a rock, carrying eggs that are unabsorbed/unlaid are all possibilities. Once she begins to eat again, feed only cooked and peeled green peas. I just take a few frozen ones and thaw them in my hand, peel and feed them to the fish. Don't feed any other foods until she is doing better.

I wish I could give you a timetable or a prognosis for her future, but without knowing for sure what's wrong I really can't say. Just do what you can by keeping the tank clean, use salt, add air and hopefully she will recover on her own. I hope she feels better soon...

At Your Service;
Chris Robbins