You gotta decondition him, both to the yard and to the boomers. The yard will be easier.
Coax him NEAR the ddor first. Reward and praise lavishly. Then closer. R&P. Then near the open door. R&P. Then on the threshold. R&P...Well, you get the idea.
For thunder, stay near him the whole storm, making him comfortable and having a good time. A few treats wont hurt either. The real trick is to watch for lightning flashes. You, but not Rex will know a boom is about to occur, so when you see the flash, PRAISE THE SHIT OUTTA HIM and pet him like youre gettin paid to do it. After a Long period of time, this Should decondition him. My female exhibited signs of loud noise(thunder) fear at an early age. For several years, she would just hang near Dad when it was thundering. I ALWAYS used the above method and now, she'll stay on another floor thru all but the worst storms if thats where she happens to be.
This may not work, but it'll help him.
Time and Patience. Rewards and Praise. You can get about anything out of an Akita with this formula.
