Thank you Rgeurts! I had thought that it was some weird chronic tick disease, but he has declined so much this year, that I spent my summer vacation testing him and trying to get this figured out. He would just get winded walking from one room to the next.
It is sounding like these things are triggered by chronic infection that is somewhat subclinical, slowly doing damage in the body. In the form that Timber might have, this is an acute and aggressive attack
Our internal medicine vet even said that SIBO can cause this, when it escapes from the gut and travels through the veins.
I think, depending on the bug and the individual, maybe there could be a chronic form, but, at least in Max's case, it's just been a long, slow decline. He is also low IgA, IgG, and IgM, so he doesn't really have many defenses against these things.
For Max, I found many of these symptoms matched: http://www.dinet.org/symptoms.htm
and started reading the forums there, which more closely match what Max is going through perhaps. From that site, I found the canine sites on this.
The world of infections, terribly scary the more I learn about them.