I am sorry to hear of your dog's possible Fanconi Affected status.
I agree completely with Terry about waiting on the thyroid panel until he is stabilized on the protocol… and making sure if he does have a UTI, getting that under control as well.
When you join the Fanconi list, be prepared that you will get tons of information, some of it conflicting. You will need to sort out what is best for your dog and you and his health. Do the protocol and hope for the best. Some dogs do very very well on it. Some do NOT tolerate it at all. I have two littermate boys with Fanconi, the one on the protocol was sick from day 1 and his body hated the protocol. His brother was sick on it, so we came to the conclusion that a better diet could make him feel better... and it did. He lived 4 years after diagnosis whereas the one sick on the protocol lasted about 2 years. Each dog is different.
I lost my old Benny to Fanconi last fall and it was the most devastating thing I have been through in my life... I have helped my dog owners with their affected dogs and will continue to do so with the last few that have Fanconi Syndrome. If you ever want to ask me some questions, feel free to PM or email me and I'll get back to you as soon as I can.
Belly rubs to the boy for me and one from Benny's kindred spirit.