Why Does Ankle Soreness Due To A Dog Bite Not Heal?

My name is Isidro, a year and a half ago a dog bit me on my ankle. Currenlty I remain with a sore that will not heal. I have consulted two doctors on separate occassions but they are not sure why it has taken this long to heal or what to prescribe me. They took an X-ray and found anthing that would indicate an infection. What should I do next?