Table 1.

Tick species, commonly reported hosts, known canine and feline pathogens, and current distribution of ticks commonly found parasitizing dogs and cats in North America.

Species	Primary hosts (stages)	Disease agents of dogs and cats	Current distribution in North America
Amblyomma americanum	White-tailed deer (L, N, A), large and medium-sized mammals (L, N, A), birds (L, N)	Cytauxzoon felis Ehrlichia ewingii Ehrlichia chaffeensis Francisella tularensis	Eastern half of North America from Gulf of Mexico to northern United States
Amblyomma maculatum	Cattle and other large mammals (A), birds and small mammals (L, N)	Hepatozoon americanum	Found 402 km inland in states along the Gulf Coast and in states bordering the Atlantic Coast as far northeast as Delaware; also found in several land-locked Midwestern and southern states
Dermacentor variabilis	Dogs, coyotes, cattle, horses, and raccoons (A), small mammals (L, N)	Rickettsia rickettsii Cytauxzoon felis	Eastern half of North America from Gulf of Mexico to southern Canada; isolated populations along the Pacific Coast in the United States, and extending eastward into Idaho
Haemaphysalis longicornis	White-tailed deer, cattle, raccoons, opossums (L, N, A)	Not known to be a primary vector of any canine or feline disease agents in North America at this time	Reported in 15 eastern states and in Arkansas, but documented distribution continues to spread
Ixodes pacificus	Black-tailed deer (A), lizards, small rodents (L, N)	Anaplasma phagocytophilum Borrelia burgdorferi	California, western Oregon, western Washington and northward to British Columbia; also, in Utah and Nevada
Ixodes scapularis	White-tailed deer (A), small mammals (L, N in northern North America), lizards (L, N in the southern United States)	Anaplasma phagocytophilum Borrelia burgdorferi Ehrlichia muris	Eastern half of United States from Florida to central Texas and northward to eastern North Dakota and Maine; also common in southern Atlantic, Central, and some Western provinces in Canada
Rhipicephalus spp.	Dogs (L, N, A)	Anaplasma platys * Babesia vogeli Babesia gibsoni * Cercopithifilaria sp. * Ehrlichia canis Hepatozoon canis * Rickettsia rickettsii	Considered ubiquitous wherever there are dogs, with populations more intense in the southern United States, Hawaii, Mexico, and in the Caribbean
Otobius megnini	Cattle, goats, horses, sheep, wild ungulates (L, N)	Not a primary vector of any known disease agent	Southwestern and southcentral states, in states bordering the Pacific Coast into British Columbia, and in some southeastern states

Abbreviations: L larva; N nymph; A adult.

^*Transmission by ticks has not been confirmed in North America.