Looks like just a bit of dried callouses to me.
If you do bag balm you only need a teeny tiny bit and rub it all the way in so his feet don't stay 'greasy' Lolita you'll end up with 'sticky paws' that have dust n fur on em. For him I would only do a very light amount once ever 2-3 days for a week and see how his feet are at the end of the week, you don't want to over do it too much and have supper soft feets... Kind of like when you walk barefoot if you have tougher calloused feet they stand up to the hard things a bit better, when you have soft feet every little stick n rock hurts (lol I use to be a bare foot kid, can you tell?)
My girls feets are much more callous looking than his! And I only bb them every few months or more..
Bumble foot happens when the feet crack, bleed, and infection sets in. It can be difficult to present infection on feet when there is an open wound, and that's where Blu kote and bag balm come into play together.
