If you guys are stressed, Rudy will be too as he seems to be a very sensitive guy, and his stress can manifest itself in many different ways with health problems being one if them. If your DH is having a meltdown, Rudy will sense it and not know why Daddy's upset.
Chase's stress resulted in staph. When we finally figured out how to make everything right for him, and after Vinnie died, the staph went away. He took wonderful care of Vinnie while he was sick. Chase's first six monts here were tough because of his previous situation and because my boy Vinnie was dying.
Dog confusion at our house was because I was /other family members were not being clear with what we wanted. Some of it was caused because the grey boys all came from different homes with different rules and they had to learn the ropes here. I realize Rudy has only been with you, but the humans at our house caused some/most of the confusion because the boys were not sure what message we were sending. And Red's confusion was due partly to lack of sleep/fatigue.
I can't remember what his doxy dosage was. Was it high enough to wipe out a TBD? I don't understand why so many vets can't figure out what is going on