Laboratory studies of tropical canine pancytopenia

Abstract Tropical canine pancytopenia (TCP) is a fatal, infectious disease of dogs characterized by hemorrhage, pancytopenia, and severe emaciation. The disease, which has been reported most frequently in the German Shepherd, has been responsible for the death of numerous military dogs in Southeast Asia. TCP has also occurred in Puerto Rico, the Virgin Islands, Florida, and the Mideast. The most striking clinical sign is a sudden onset of epistaxis in an apparently healthy dog. Pathological findings consist of petechial and ecchymotic hemorrhages on serosal and mucosal surfaces of numerous organs. The disease has been successfully transmitted to laboratory dogs. Experimentally infected beagles and mongrels develop clinical signs consistent with the natural disease; however, clinical signs of hemorrhage, including epistaxis, have been experimentally induced only in the German shepherd. Ehrlichia canis has been identified as the etiologic agent of TCP.