Can you get your vet to test it for thrush or canker. Since it sounds like there has been pox in the area of the chickens, it could still be wet pox. Those 3 things are all possible, but as I said in your other thread, canker is said to have a bad odor. Thrush, candida, or yeast is a fungus and is treated with antifungal medicines. Nystatin or Medistatin powder can be found online. I don’t know if the antifungal creams (Monistat, clotrimazole, miconazole) will help, but might. There is no cure for wet pox, and it will eventually go away. You have the info on canker from your other thread.