Heel grubs?

Any experience with this in a horse? From googling, I think that’s what I have going on with my new 3 yr old. She lived with a cow before I got her and it seems like more of a cow thing? Two weeks ago I noticed filling in left hind ankle, and saw a small circular wound at the bottom of her pattern/just above inner heel bulb. I cleaned it up and thought we were good but it won’t heal - and now I see a small circular wound on the right hind pattern.

I was reading about summer sores last night and I think that’s may be basically the same thing? I have zero experience with this but it sounds very gross :face_vomiting:

Vetericyn has a good product, comes w/ spray and is great for getting summer sore type things
To heal Flies avoid the sprayed area. Also keep that area dry.