It could be a type of bumble foot. Not the usual kind though.
Here is a bit of information taken from the website PoultryPedia.
https://sites.google.com/a/poultrypedia.com/poultrypedia/poultry-podiatry
Treat Bumblefoot Infection
Note: People who care for raptors (birds of prey) often call thick foot callouses "bumblefoot." Poultry keepers usually only call a foot problem "bumblefoot" if there is infection inside.
Possible Symptoms:
Foot pain, swelling, lameness, hard callous lumps, and sometimes red or darkened area, scabbing or crack in skin on feet.
Cause:
Usually caused by cut or bruise, often from landing too hard because of a too-high perch or rough or hard ground.
It can also be caused by chafing from perches that are too smooth and/or too narrow for the bird's feet.
Note: Chickens are designed to mostly 'stand' on their feet rather than 'perch'--unlike lighter weight birds (such as sparrows) or long-winged birds (such as hawks) that more tightly grip and curl their feet around perches.
If there is also infection involved, it will likely be a staph (staphylococcus aureus) infection. This infection can spread into other areas of the bird's body and may cause death.
Prevention:
Provide perches that are reasonably wide (minimum of 1 3/4" for bantams, 3 1/4" for large fowl), and have texture (such as natural branches, or boards you roughen up) where possible. Don't provide wood dowels or ladders for perches. If you use 2"x4" boards for perches for large chickens, turn so the 4" side is the top side.
To prevent large birds from bruising their feet, make sure there are no perches higher than ~3 1/2 feet from the ground and that landing area has soft, thick layer of bedding (pine shavings, play sand, etc.).
Keep coop and perches sanitary and dry. Scraping poop off of perches regularly. It may help to sprinkle them with Food-Grade Diatomaceous Earth or spray them with disinfectant such as Oxine (but NOT bleach mixture--Bleach only disinfects on surface, but water mixed in with it penetrates to interior and may foster germs.)
Trim any excessively long toenails so your bird can use its feet correctly when landing, etc.
Every few months, check feet for callouses that may become problematic.
Treatment:
Trim any excess dead skin from the area. The safest method is generally using toenail scissors and working in from the edges of the callous. There is greater risk of accidentally cutting into live skin if you start trimming on the top surface of the callous and working your way down. When trimming, be careful to not pull too hard on other attached skin.
Soaking feet in warm water before trimming can be helpful. Mixing some Betadine in water may help clear infection.
You can apply Triple Antibiotic Ointment (kinds such as Neosporin-- without added pain relief ingredients, which may be harmful to birds) before and/or after trimming to help soften skin and alleviate infection.
Re-examine feet after 2-5 weeks and repeat trim treatment if necessary.
If there is much infection involved, consider giving Penicillin injections (See "Treating with Penicillin" section). Penicillin is much better than almost any other antibiotic for this kind of infection. It provides quicker, reasonably inexpensive treatment.
Additional recommendations vary, and can include antibiotics, soaks, poultices, bandages (*Change frequently), lancing (*May not helpful in some cases. You might not want to lance minor infections. If you do lance, do your best to get the hard "bumble" lump out and scrape out all pus.), restriction of movement, lowering or removal of perches, and clean environment.
One good treatment system is listed at
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=87896
An innovative treatment soaking foot with product usually used for fish is described at
https://www.backyardchickens.com/forum/viewtopic.php?id=303829
You can buy neoprene Chicken or Duck Shoes at
http://www.indoorducks.com/shoeinfo.html to keep your bird's feet clean and cushioned while healing.
There is additional helpful information at
http://fowlfacts.proboards.com/index.cgi?board=afflictiondiseaseff&action=display&thread=1202
Prognosis:
Problem may not be noticed until has been present for an extended time. Even with treatment, Bumblefoot can sometimes develop to be chronic. Unfortunately, if it includes infection, it can lead to death in prolonged or extreme cases. However, some treatment methods have good success rates.
Or it could be a pox type thing. Fowl poxes usually affect the face but it can make lumps and blisters on the legs too.
This is taken from this website
http://www.daff.gov.za/docs/poultry/featherskin.pdf
Pox
*Pox is a viral disease that is transmitted by mosquitoes. Pox sores are seen on the unfeathered areas such as the head, neck, feet
and legs. The sores begin as red pimples which develop into pimples filled with fluid (vesicles) and then pus (pustules). Finally, as the pustules burst open, crusts or scabs form.
You could ring a vet about it. Maybe they could take a sample from around the sores to test.
Good luck, keep us updated.
) feet. I noticed little scabs over slightly raised, hardened tissue two days ago. One looks like it may have pus under the scab. The little guy also has what looks like a blood blister on his hock which has been there pretty much since birth. They are hand reared and are in a very clean and dry environment. I tried a condy's crystal solution (only good for fungal infections though?) 24hrs ago and they seem a little drier. Is there anyone who has seen the same thing or who can offer a treatment plan for him? It's odd because the sores are in the same spot on each of his feet. I haven't seen anyone pecking at him and otherwise he seems to be a very happy and healthy little fella! I'm thinking maybe staph? Has anyone tried a dilute 3% hydrogen peroxide solution for wounds?
