My gourami is sick!

Question

Deep flesh sores on Go   I have 5 gouramis, and 1 platy. I have a really sick gourami, who seems normal and happy, but has huge open flesh sores on his side. He has had it for about 3 weeks and it has gotten so bad.. I had a tiger barb about 2 months ago who died, and i had noticed on his tail it looked like he was missing a chunk of his scales and flesh, i could almost see his bones, he died a week after and i never found the body. I researched it but couldnt find a disease that had the symptoms, besides "fish TB". My fish dont have crooked spines though. I read that if its parasites, and the gourami ate the barb he could have gotten it. But I don't know what to do, all the fish are fine and happy, very friendly and calm.. I hope you can help!

Answer
Hi Krista,
Wow, thank you for the picture.

That is quite drastic flesh sores on your gourami. Not very common for sure. My first guess without knowing any better is that another fish is attacking him. And it really does look like fish that have been fighting. Gouramis are territorial and they may be fighting when you aren't there to see it (it happens sometimes).

From the pictures it looks like skin is definitely torn. But the area seems to not be inflamed or red as it would if there was a bacterial infection going on, which would be one of the most common culprits for fish to develop sores. The fact that the fish isn't behaving sick is also odd. If any other fish had an illness that looked as far gone as this fish's wounds, he would be very sickly and likely on his last breath.  

And since your Tiger barb was missing a chunk of his scales and flesh I'm definitely wondering if there is a dominant fish in your group. There is often a pecking order within a school of gouramis and your sickly one could in fact be at the bottom.

I really doubt it's an illness or parasites. What I'd do is isolate the gourami to a 10gal, change 50% of his water everyday, and be sure to have a heater. Clean water is essential for proper healing.
Keep him in this hospital/isolation tank for a couple of weeks to see how his condition remains. I don't feel comfortable advising medications at the moment because blindly medicating fish can do more harm than good.

Fish TB is rare. And is usually accompanied by other symptoms like wasting away and skeletal deformities as you mentioned.

See what happens when you isolate the gourami. That would definitely be your best bet in a case like this.

I hope this helps and best of luck!
Happy Holidays~
Susan~