My Jed had ehrlichia. Our first vet wasn't able to diagnose him, he was treated for several bladder infections until we switched vets. Our current vet nailed the diagnosis almost immediately.
Stress would cause Jed to have a flare up. Now that you've got a diagnosis, Doxy is the key. We would pretty much get Jed on Doxy anytime he would start to act a little off. If he peed in the house, it was 8 weeks of doxy. When we first realized it was ehrlicha, Jed was also put on Prednisone (pill form) for the first 2 weeks and we treated with Doxy for 8 weeks. After that, when he'd have a flare, our vet would give him a shot of prednisone and send us home with doxy. Flares would also make Jed's temp shoot sky-high (105-106), so if he ever seemed off, I'd take his temp, too.
Jed lived a long, happy life post-ehrlichia diagnosis.
Daisy, our little found-hound, has Lyme disease. Because we caught it during her first flare-up, and treated it so quickly, my vet believes that it may not be an on-going condition for her - - that we may not have to worry about other flare-ups in life. I hope that the same is true for you and your hound, that you guys can knock this out now and not have to deal with it again later. But if you guys do have to deal with the occaisional flare-up, I hope that it's similar to my experience, and something that can be managed easily.