Granulocytic anaplasmosis is an emerging infectious disease affecting dogs and humans in the United States and other regions of the world. Relatively few cases have been described in pregnant women, and perinatal transmission appears to occur infrequently in humans. Infection in pregnant dogs has not been reported. Diagnosis of infection during pregnancy poses therapeutic challenges, because doxycycline, the treatment of choice, is teratogenic. Also, infection during pregnancy may result in more severe disease. When infection is diagnosed after parturition, knowledge of the risk of perinatal transmission to offspring is important, because prophylactic therapy in neonates is also not without risk. In this report, we describe relatively severe clinical manifestations of Anaplasma phagocytophilum infection in a postpartum bitch and a lack of perinatal transmission to her puppies.