DSH 20121
Thanks for posting. Dogs certainly can be destroyers. I believe this is our 23-038, but just make sure the nylon part on top looks the same as what is shown below. Let me know if you have further questions.
If your top guide uses wheels, you may need something like the 23-222C. I'd recommend removing an intact guide from the door to determine which part matches your specifications.
The 23-038 wasn't designed to work with wheels, this is just a basic guide that goes in the track. If your roller had wheels then I think my initial recommendation was mistaken. You likely have something else.
Would it be at all possible to see what this assembly looks like out of the track? That might give me a better idea of what you have and whether we sell a better alternative.