My cat is 13 years old and he developed thison his upper lip. Took him to the vet and got an injection and it went away. Months later it came back. Took him back and got another shot. It got a little better. Long story short he has it again and we changed food went backto thevet for another shot and blood work. Everything was fine. They say to try and treat him with steroid or antibioticsand I don't want to do either but someonetold meto try holistic grain free food and colloidal silverandlysine. Does anyone know how to treat this naturally? I know he is in pain.