Need advice on Red Eyed Tetra Gills

[AquaticNerd]

I acquired 3 Red Eyed Tetras about 7 weeks ago. Long story short, they were not returnable and were received in pretty bad condition. They were all 3 covered in ammonia burn, and 2 of the 3 had what looks like severely inflamed gills. Two of them have deformed mouths. One unable to close, the other bent to the side a bit as well as a deformed spine. They have gone through a round of General cure, and Furan-2 and that cleared the redness on their bodies, but there has been no change to their gills. The female looked normal aside from ammonia burn, and has not gotten any worse either. The 3 of them all have healthy appetites and exhibit normal healthy tetra behavior. I have not witnessed any flashing or stress from them despite their afflictions.

I originally suspected gill flukes just based on the condition of their gills, but I have never had experience with flukes so I was looking for some advice. Is it possible that they were injured or just born this way, or could these fish be infected with gill flukes for 7+ weeks without getting any worse?

They are in a quarantine tank. It is about 9 gallons with 25-30% water changes weekly. Ammonia and nitrite is 0ppm, nitrate 10ppm. I will attach some of the photos that I have of them and take better ones when I get home.

 

[SaraB]

Poor breeding can cause deformities. Are they gasping for air at the top? Are they rubbing against things?
You can use a salt bath to help get rid of them, or an anti fluke medicine.

 

[AquaticNerd]

No gasping, scratching or flashing, it just looks uncomfortable, though they don't act as if it is bothering them. I am not concerned with the mouth and spinal deformities, I just assumed they were poorly bred or possibly injured, but the gills just seem off. I have treated for flukes and noticed no change whatsoever. No improvements, but nothing got worse either. My wife brought them home. She did say the woman netting them seemed unusually rough and wondered if she might have caused injury to a couple of them.

 

[SaraB]

Maybe the gills are also a deformity. If it's not bothering them then I don't know what else it could be.
Just make sure that there are no decorations that they can get stuck on.