Yep, those are at the very least "pressure sores" that are going to turn-into Bumblefoot, or they already are the start of Bumblefoot (I'm pretty certain they are, though you need a Certified Avian Vet to look at him to confirm in-person).
Bumblefoot is just a b***h to treat/cure, because the ONLY cure is getting pressure completely off of the foot/feet, and with birds and small animals like rats and guinea pigs who get it most-often, it's nearly impossible. However, you can hopefully stop it from getting any worse by first making sure that he doesn't have any perches that are either wood or plastic "dowel rods", usually the ones that come with cages, that are all one uniform shape, and that keep pressure always on the same exact spots on their feet. Think about birds in the wild, they stand/perch on tree-branches, which are never at all all one uniform shape, they are wavey and have different indents, curves, bumps, etc. So the best way to stop this from getting any worse is to toss all dowel-like perches and replace them with perches made from natural branches that are not all "uniform" in shape. Most pet shops sell all kinds of differently shaped perches, and made out of different types of branches. That's the first thing you need to do is get different natural branch perches and put them throughout his cage, and if he sits on anything outside of his cage, such as some kind of stand, make sure that it too is a natural-branch perch or at least shaped like a natural branch.
As far as treating the Bumblefoot that is already there, it's luckily not too bad yet, so it may resolve itself if you get different natural branch perches for him ASAP and make sure that he's only standing on them and nothing else that is "uniform" in shape, so that the pressure will be relieved from those same areas he always puts pressure on when standing/perching on the regular perches. The less uniform the perch's shape the better.
As far as a medical treatment for Bumblefoot that works, the only one that I've seen actually work well was a Vet who had a Laser in their office, and they would laser each Bumblefoot spot after all of the perches were changed-out to natural branches, and they would have the owner stop-in with the bird once or twice a week to have the spots lasered (which takes all of 10 minutes and is completely and totally painless and requires no sedation or anesthesia). The laser works extremely well to increase blood-flow to the areas and increase healing time to less than half. And in the case of Bumblefoot, it's the only thing that works...Well, that and the little "cage-booties" I've seen built out of casting material cut into strips and then formed to the feet, so that they form a cage around the feet, which the feet actually not touching the bottom of the bootie and the animal walking/standing on the the bottom of the bootie (which is hard as a rock because it's casting material), and their foot is actually suspended above the bottom with a space between the bottom of the foot and the bootie...But that was something that the Vet came up with on their own, and it worked liked a charm along with the laser treatments...If you can find a Vet who has a Laser in their office for treating wounds, that's your best bet...Usually a lot of "Exotic's" Vets and hospitals, the larger ones, have lasers that they use on new incisions right after surgeries, and on any animals who come in with wounds. It really works. It's just a matter of finding a Vet who has a laser...
