Mason212

The black marks are receding now, thanks for the advice. I reckon now it was caused by excess ammonia as said in the thread,

Thank you for for the advice. I will start preforming the water changes. Id like to add that I accidentally said pond weed, the treatment I put in my pond is for blanket weed and thats only when it gets out of control.

Can anybody Identify the disease on this fish, he is around 5 years old and has never had any health complications before apart from a benign growth on his back. If the issue can be identified then can a treatment be recommended. I have checked the ammonia content of the pond and it is safe so ammonia burns should not be the issue. the fish himself is acting normally. The black marks are located on the gills, above the mouth and on the nostrils