I will add to your reading list:
http://www.pets.ca/forum/showthread.php?t=73066
Unfortunately, in suspected tick disease, many vets to a fatal combination, 1) under treat with doxycyline (aggressive dose is 10 mg/kg, which is approximately 5 mg/lb) which only at higher doses kills organisms, and 2) they add pred too soon, which interferes with the action of the doxy. Pred should only be added when the RBCs or platelets are dangerously low, not just low. Once though you get to that transfusion state, you do need the pred, or sometimes a different immune suppressant. Dodds has an AIHA protocol which may help.
Testing for tick disease would be important to do.