Hello, I'm Dr. Deb. Thanks for requesting me but I'm sorry that I was off my computer when you did so.
I agree that I would have expected her to have shown significant improvement by now as she has done in the past.
I don't necessarily think that she's immune to the Doxy but
my concern is the chronic nature of this condition.
The prognosis for dogs with chronic Ehrlichia isn't as good as for those with acute disease, unfortunately. Even though blood was normal about one week ago, it may not be now.
If it's repeated and all of her cells lines are low, then the prognosis is not good that she's going to get past this episode although it gives me no pleasure to say so:(
It may be prudent to repeat the bloodwork if possible to see if her blood work is abnormal.
It's possible that there are other infectious agents at play
here or something else is going on since her response is so atypical from her past events.
I hope this helps although, again, my apologies for the delayed reply. Deb