Hi, I just thought I would jump in here since you were looking for a certified farrier.
I am not a certified farrier but I have taken a seminar that was hosted by a Strasser Hoofcare Professional and the clinician was the President of the Equine Soundness Association also known as the ESA (Strasser method training in North America).
From what I see from the picture, your horses heels are uneven and are starting to become underrun. Now, my horse went lame after 6 weeks of shoes and developed a crack that started at the coronary band and went all the way down to the ground. I was unable to get my regular farrier out so I called this lady that did barefoot. Found out later that she is SHP CERTIFIED and I haven't looked back.
One thing that I must stress is that correcting/healing your horse is going to take much more than just trimming. You must look at your horse's metabolism, living conditions and environment in order for the healing process to progress.
There are many people out there that are quick to slam Strasser but I also think that those people need to look at the whole picture as to what it takes to heal the horse. Also, yes, I am sorry, I am on a Strasser rant here, all SHPs must go for yearly recertification in order to hold onto the SHP status. Another note of interest, is that the President of the ESA is also a VETERINARIAN, therefore, all SHPs have vet advice at their convienience.
Plus, the Strasser trimming course is now a 2 year course! I am very sorry but I would rather have someone that went to school for 2 years work on my horse than someone who took a weekend trimming course and is out trimming for a living....
I am not saying that all other natural trimmers don't know what they are doing, kudos to them for promoting the barefoot movement!
I urge you to read Dr. Strasser's book - A Lifetime of Soundness and to visit the ESA North America website Natural Hoof Care, Strasser Hoof, Laminitis, Navicular, Coffin Bone