Fish Problem

Question
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Hi Chris,
Thanks for the quick response.  You mentioned in your answer that our bass needs to eat in order to heal because the internal parasites are treated in the food.  How?...Is there medicated food he needs to eat?  You mentioned putting Maracyn 2 in the tank, but I think that is a tablet that you just drop in the water.
Followup To
Question -
Hi Chris,

We have a small bass in our tank that has stopped eating.  We rescued him when he was caught on our line fishing and didn't think he was going to make it.  We put him back, but he floated so we thought we'd try to nurse him back to health before we released him.  We have had him for about 2 months, and he was doing well up until a couple of days ago.  He was eating about 6-8 goldfish every other day along with a periodic nightcrawler.  As soon as the goldfish were put in the tank he would swoop up as many as would fit in his mouth.  Now he shows no interest in eating at all.  He is in a 60 gallon tank with an medium sized Oscar, a Pacu, a small Green Terror and two small Convict Cichlids.  Our tank is not new, so it has been through the cycle.  Our ph level fluctuates between water changes.  It is usually about 6-7.  Our ammonia level is 0 and our nitrite level is less than .3.  We do have a minimal (1/4 of the recommended) amount of salt in the water.  A few days ago I notice a red mark around his fin behind his gill.  It almost looked like flesh.  Do you think that might be some kind of parasite and if so, how did he get that and are our other fish at risk?  Also, his lower belly seems to look "sucked up"...he was well rounded and looked very healthy.  We were considering releasing him soon, but now he's sick.  Before this change he would swim around the tank with all his fins high and beautiful and now he seems to be cowaring.  If that isn't the problem, what else do you think could make him stop eating?  We've grown really attached to him and want him to be healthy enough so that we can release him.  When we first got him, he was really beat up...he had many wounds besides the one from the hook.  All of those wounds healed and he was getting stronger.  We are puzzled as to why he has taken a turn.  Any information would be greatly appreciated.
Answer -
Hi Kim;

Poor guy. He may have been attacked by one or more of the other fish. Redness usually indicates a bacterial infection or just bleeding from a wound. It might be best to separate him from the other fish until he gets better. Use an antibiotic like "Maracyn 2" and also some Melafix to help him heal. You don't want to medicate the big tank. It isn't good for the other fish to medicine they don't need. It can also make the tank into quite a mess. Medicines can make the water turn colors for a long time and get foamy, as well as be very expensive to administer in such a large size tank.

It is also possible he has intestinal parasites like worms or protozoans. They are very common in wild fish. If the fish has been stressed, the parasites take the opportunity to multiply. Unless you can get him feeling better there isn't much you can do to treat that. He has to eat in order to be treated for internal parasites because it is administered in the food.

I hope he feels better soon.....

At Your Service;
Chris Robbins

Answer
Hi Kim;

The Maracyn 2 is to treat the possible bacterial infection. Unfortunately it will not work on internal parasites.

There are internal parasite medications that you put in their food and also pre-made pellets that have the anti-parasitic medicine impregnated in them. It can be very risky to treat a sick fish for internal parasites. Some of the medicines used are very potent. Check out what your local fish store has on hand for that and read the labels to see what they recommend for the symptoms your fish has.

Poor guy, I hope he feels better soon.....

At Your Service;
Chris Robbins