4 month old EE w/ swollen feet, trouble walking
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I would start some poultry vitamins in his water right away. Can you post a picture or two of his legs? There are certain conditions that can cause swelling of the feet, such as gout and mycoplasma synovitis (MS.) Curled toes sounds more like a vitamin B2 deficiency, though. Have you seen any respiratory infections before? You might also check the bottoms of the foot pads for any swelling or dark spots which may be bumblefoot.
Here is some infomation about mycoplasma synovitis (MS,) the respiratory infection similar to MG that causes joint swelling, and others on gout and vitamin deficiencies: