EhrlichiaEhrlichia chaffeensisEhrlichia canisEhrlichiosisEhrlichia ruminantiumRickettsiaceaeRickettsiaceae InfectionsAnaplasmaDog DiseasesTicksAnaplasmataceaeIxodesHeartwater DiseaseDogsTick-Borne DiseasesHorse DiseasesTick InfestationsAnaplasmosisAntibodies, BacterialRNA, Ribosomal, 16SArachnid VectorsPolymerase Chain ReactionNeorickettsiaHorsesAnaplasma phagocytophilumDNA, BacterialRickettsiaArthropod VectorsAntigens, BacterialIxodidaeAnaplasmataceae InfectionsDeerBabesiaRickettsieaeRickettsia rickettsiiMolecular Sequence DataAnaplasma centraleRhipicephalus sanguineusDoxycyclineFluorescent Antibody Technique, IndirectBartonellaSerologic TestsChaperoninsDisease ReservoirsChromosome WalkingGranulocytesPhylogenySequence Analysis, DNADNA, RibosomalAnaplasma marginaleBacterial ProteinsSeroepidemiologic StudiesBacterial Outer Membrane ProteinsOxytetracyclineArgasNymph