Ouch! Poor Gertrude. That definitely doesn't look comfortable.
I've successfully treated very severe, stubborn bumblefoot infection with essential oils, including infections on two of my birds that were, though not quite as swollen as in these pictures, approaching that point rapidly despite the multitude of other treatments I had tried. I use a mix of 42 drops fractionated coconut oil (the kind that stays liquid all the time), 7 drops tea tree essential oil, 7 drops lavender essential oil, and 7 drops oregano essential oil. This makes enough for my flock of twelve. I pick up the chicken, spread the mixture on the foot, and let them go again, no other treatment required. Essential oils are strong, so it is important to make sure that you are using a carrier oil (like the coconut oil) if you do choose to use this method.
For severe infections like this, I try to treat 2 or 3 times per day, but I've seen amazing progress even with treatment once per day. I will usually soak the chicken's foot in Epsom salts, too. I have the chicken stand in a bowl or dish of some kind, filled with warm water and Epsom salts just enough to cover the infected area, for roughly 10 or 15 minutes. Sometimes, I will add 1 drop each of tea tree, oregano, and lavender to the soak for added strength. It is important to note here that essential oils can cause eye and respiratory irritation, so I do monitor them while soaking just in case. I have never had any issues with that, though.
Wishing you the best of luck with healing her!
