Omega-3 Improves Your Pet Health

I adopted my cat from a shelter last year. He was in poor health and had spent 1 month in the Intensive Care Unit because of that. He is also an indoor only cat. He has gradually become a little love, but as soon as I go barefooted, which is now impossible, he literally attacks them like a wild animal would and it causes lots of pain. Again, he only does this with MY bare feet for some reason. Other than that, he’s close to me and loves to play and have fun. Is this always going to be a problem? Could he have been a feril cat when the adoption shelter rescued him, or is this just a personality trait? Once again, I thank you all in advance for your help!!