Ehrlichiosis Information:

CDC human & animal Ehrlichiosis, with table of Ehrlichia species
CDC's Human Ehrlichiosis bibliography
Oklahoma State University description of various Ehrlichia species
Ehrlichiosis forward by Dr. Kakoma
Vetinfo.com canine Ehrlichiosis
Israel Veterinary Medical Assoc. canine monocytic Ehrlichiosis
VetCentric Potomac Horse Fever

Consultant Ehrlichiosis:

Bovine ehrlichiosis
Canine granulocytic ehrlichiosis
Canine monocytic ehrlichiosis
Equine granulocytic ehrlichiosis
Equine monocytic ehrlichiosis (Potomac horse fever)
Feline granulocytic ehrlichiosis
Feline monocytic ehrlichiosis

Bibliography (from PubMed)

Bovine
Equine
Canine