I wouldn't think that 'sore' would be from spawning as it's on the top of the fish.

I'm not sure how big your pond is, but you may want to consider adding some kosher salt to help with the fish's slime coats.


Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."