disease of humans and dogs. Confirmation of the protozoal agent in bone marrow, lymph
node or spleen aspirate is diagnostic, while specific-IgG serology is used mainly for
epidemiology despite the general presence of high levels of serum immunoglobulin.
Anecdotal reports of false-negative serology in active disease cases are known and are
ascribed to the formation of immune complexes. Because dissociation of immune complexes …