Oscar fish appears to have "swollen" vent

[mickey33]

I have 2 Oscars in a 120 gallon tank. They are both about 9". One of them appears to have a swollen vent area, I noticed a white "discharge" from it yesterday, but now today the white is gone but it is swollen, any suggestions?

[rED O]

I am going to make two guesses on what it might be. Only one of which you can treat. Epsom Salt baths are effective in treating constipation but the treatment may need to be repeated. My other guess is that the high nitrates have resulted in internal organ damage, of which the swollen anus area is a symptom.

[BettaFishMommy]

possibly internal parasites? i'm no expert on fish diseases, but that's what i might think of with white discharge and a swollen underside.

[mickey33]

You could be right about the nitrates. I got the fish about a month or so ago, there were 3 of them in a smaller tank, about a 90, the tank was so merky, that they were almost impossible to see to catch them. I brought them home to my cycled tank, and there was high nitrates so I did water changes and tests daily. The biggest Oscar about 12" did die, but that was about 3 weeks ago, so I thought that all was okay, but maybe the internal damage is showing up now. They are both eating fine, and look good, except for the swollen anus.

[rED O]

You could be right about the nitrates. I got the fish about a month or so ago, there were 3 of them in a smaller tank, about a 90, the tank was so merky, that they were almost impossible to see to catch them. I brought them home to my cycled tank, and there was high nitrates so I did water changes and tests daily. The biggest Oscar about 12" did die, but that was about 3 weeks ago, so I thought that all was okay, but maybe the internal damage is showing up now. They are both eating fine, and look good, except for the swollen anus.

I would do lots of water changes but if its his internal organs, the damage is already done.