Anaplasma phagocytophilum (previously known as Ehrlichia equi) is a tick-borne emerging pathogen that affects a variety of hosts, including humans.1 In November 2009, clinical anaplasmosis was confirmed in two captive maned wolves (Chrysocyon brachyurus) at a facility in Front Royal, VA, USA. Affected wolves exhibited coughing, tachypnea, and severe pulmonary congestion, splenomegaly, ataxia, anorexia, lethargy, and dehydration. Mild jaundice and petechiation were seen in one of the two affected animals. Clinical pathology findings included leukocytosis, anemia, and hyperfibrinogenemia. Diagnosis was confirmed by characteristic neutrophilic inclusions in peripheral blood smears, and PCR testing. A presumptive diagnosis was made on a third wolf, based on clinical signs, response to empirical therapy, and elevations in paired antibody titers. All animals recovered after treatment with doxycycline (300 mg PO BID for 21 days), but one animal (with more severe respiratory signs) concurrently received enrofloxacin (204 mg PO SID for 7 days). Serologic screening of eight adult maned wolves, including the affected animals, showed a 100% seroconversion, suggesting that maned wolves can be infected, not exhibit clinical signs, and apparently clear infections. A. phagocytophilum was originally detected a year previously at this facility, but prior to the current cases, no maned wolves had ever been affected. Prompt diagnosis and treatment when clinical signs appear are associated with a good prognosis for recovery from A. phagocytophilum infections.
1. Dumler JS, Choi K, Garcia-Garcia JC, Barat NS, Scorpio DG, Garyu JW, et al. Emerg Infect Dis. 2005;11:1828–1834.