Thank you all for the info. I think that pretty much answers it I think. But for real Thanks for takeing the time to look that up for me.
Could be lamprey bites.
This may help. VM85/VM059: "Red Sore Disease" in Game Fish
New Page Is this the skin condition you are describing? Click on "New Page" for more information. I learned that catfish farms can and do harm the wild fish populations. When groups of animals are concentrated into a small area, the potential for bacteria or viral outbreaks is greatly intensified.
They where pretty much covered with them.
I'm not sure if I can help ya with this.. but my buddy caught a bullhead that had one of those sores that you described right under its bottom lip. A huge red lump, nasty looking, somewhat like a zit. I figured it was an infected wound from a hook. Are the channels covered in spots? or just around the mouth?