Canine Granulocytic Anaplasmosis: A Review
Version of Record online: 16 SEP 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 23, Issue 6, pages 1129–1141, November/December 2009
How to Cite
Carrade, D.D., Foley, J.E., Borjesson, D.L. and Sykes, J.E. (2009), Canine Granulocytic Anaplasmosis: A Review. Journal of Veterinary Internal Medicine, 23: 1129–1141. doi: 10.1111/j.1939-1676.2009.0384.x
- Issue online: 27 OCT 2009
- Version of Record online: 16 SEP 2009
- Submitted April 4, 2009; Revised June 15, 2009; Accepted July 31, 2009.
- Anaplasma phagocytophilum;
- Tick-borne disease
Anaplasma phagocytophilum is an emerging pathogen of humans, horses, and dogs worldwide that is transmitted by Ixodid ticks and maintained in a variety of small wild mammal species. Recent studies suggest that multiple strains of A. phagocytophilum may be circulating in wild and domestic animal populations, and these strains may have differential host tropisms and pathogenicity. The organism infects and survives within neutrophils by disabling key neutrophil functions, including neutrophil motility, phagocytosis, the oxidative burst mechanism, and neutrophil-endothelial cell interactions, as well as interfering with neutrophil apoptosis. Coinfections with other tick-borne pathogens may occur, especially Borrelia burgdorferi. A. phagocytophilum causes an acute febrile illness in dogs with lethargy and inappetence. Less frequent signs include lameness, coughing, polydipsia, intermittent vomiting, and hemorrhages. Diagnosis is based on finding morulae within granulocytes in the peripheral blood, the combination of acute and convalescent serology using immunofluorescent antibody techniques, and detection of the DNA of A. phagocytophilum using specific polymerase chain reaction assays. Whether persistent infection or reinfection with A. phagocytophilum occurs after natural infection requires additional study, with most reports suggesting that anaplasmosis is a self-limiting disease in dogs that responds well to a 2-week course of doxycycline therapy.