hi, new oscar owner, recently rescued 2 oscars, previous owners young and broke, oscars history jaded, don't know how ages. female-is white, in pristine condition, possible stunted growth. male - is in dire condition, he is green with orange spots- He came with one cloudy eye and scales missing from his sides-told was because she fought him...I have had them for 3 months and he is getting worse, never seen them fight, just posture. He appears to be suffering from numerous ailments, Fin Rot, HITH, bacterial hemorrhagic septicemia, 1 cloudy eye, the other has a cottony growth under it (this is new), and possibly a curved spine. no doubt the onset of these conditions was due to bad care.. and since she doesn't seemed to be suffering at all I am terribly worried about fish TB. I have started with neomycin feeder drops which he ate at first and showed a slight improvement but he isn't eating at all now- so I have switch to Melafix- antitbacterial fish remedy that is put into the water- this treatment so far 4 days-color improved, HITH seems better, Q: 1 fish sick, other healthy-TB? possible curved spine but not sure if due to internal parasites- stay with current treament for 10 days -25% water change and start Kanamycin + vit B6 or euthanize-very worried about it TB

Welcome to the site.
Okay, the problem your fish have is most definitely caused by a poor water conditions.

A few questions, how big is the tank, how many fish in the tank, and what sorts of filtration have you got? Also, have you tested the water for ammonia, nitrites, nitrates and pH. You say you have been carrying out water changes, this will definitely help keep the water in good condition. Have you done anything with the filtration?

Now on to the fish, are any of them breathing heavily? The problem with fungal and bacterial infection is there are lots of different types. In an ideal world, you would have a smear taken off the fish so it could be examined, then you would be prescribed with the correct medication. However, this isn't always an easy option so you may have to try various medications until the find one that works. I'm afraid I'm not going to be able to be much help because I don't know exactly what is affecting your fish. Your best bet would be to approach a veterinarian. Everyone will give you an opinion on our forum and probably other forums at the end of the day, most of it is guesswork, it's impossible to successfully diagnose a problem over the Internet.

Melafix might help with the fungus and fin rot, but it's not guaranteed. What you could do is try using pimafix. this can also treat fungal infections, as well as external and internal bacterial infections. It is designed to work alongside melafix. Another medication which may help is myxazin. But don't use this at the same time as using the other two.

When a fishes body is deformed, this can certainly be a sign that the fish is stunted. However, just looking at the size of an Oscar can tell you if there's a problem. An adult Oscar should be at least eight or 9 inches long. If it is a lot smaller than the chances are, it may be stunted. Curvature of the spine can also be caused by other ailments such as tuberculosis. In circumstances like this, euthanasia is the best option. Parasites can also cause a fishes spine to become curved.

The cloudy eye could be caused by two things, poor water conditions, or lack of nutrients. Feeding your fish on vitamins might help this, hopefully the eye isn't beyond repair. However, it might be too damaged and will just stay like that. You might want to try and find some vitamins from somewhere. But like you said, if the fish stop speeding, it's very difficult to get these vitamins inside the fish.

Okay, keeping the ammonia and nitrite at zero, and nitrate below 40 ppm will certainly aid your fishes healing.

I am sure there is something out there that will help your fish. Finding the correct medication is obviously the key. I would strongly urge you to visit a vet, the longer this goes on, the worse things will get and you will get to a stage where there is no return

thank you so much for reading and responding- there are 2 fish in a 75 gallon tank I have 1 double filter and 1 single filter- standard carbon cartridges, and 2 aireator bars each 12 " long. I suspect both fish are extremely undersized and they could possibly be a couple of yrs old they are maybe 6 inches long-I purchased a 5 in 1 testing kit and will test the water,introduced water is well water, no symptoms of heavy breathing have been observed and the water is clear. However I noticed while working with the tank the heater isn't working properly. Water temp maybe an issue with recovery- 1 observation I noticed I used warmer water during the water change and the male seemed to become more active and open what is left of his fins,and he may have even been less curved ( maybe just hopeful thinking though), I read somewhere that the swim bladder can harden if the temp is too low- possibly why he appears curved. I will get a new heater and purchase pimafix and continue treatment- note: I have read that need to suppliment diet other than feeder fish and got some large nugget type food-(fortified)she loves them but he hasn't eaten as of yet-since the carbon filters were removed for medicating I don't want to run the risk of feeding too heavily and causing an amonia problem that way. I am using rubber gloves and trying to educate the kids about the danger of fish TB- since there isn't any open sores other than on the fins- coudl tb be cured or with the fish always be contagious?

GH 120,KH 0/40, PH 6, NO nitrite(2)=.05, NO nitrate(3)=80/160 for this species reading say general hardness good, carbonate hardness too low???? resulting in unstable PH causing stress, tend to be acidic??? sounds like I need a a non carbonate buffer, if PH becomes unstable.not sure about nitrite and nitrate levels what my ranges should be and whether the filters not being inplace is having an effect- I need help understanding this part!

You need to get your nitrate down by doing water changes. You need to keep it below 40

ok I thought mayvbe with the filters being out was having an effect I haven't done a water test in the last few days but I need to do a thorough cleaning of the tank due to possible disease in tank-thanks for the feedback