spp. from Dogs and Cats in the United States: Diversity, Seasonality, and Prevalence of and .

spp. are commonly found on dogs and cats throughout the world. In the eastern United States, sequence of , the predominant species, reveals two clades-American and Southern. To confirm the species and clades of spp. ticks submitted from pets, we examined ticks morphologically and evaluated sequence from 500 ticks submitted from 253 dogs, 99 cats, 1 rabbit, and 1 ferret from 41 states. To estimate pathogen prevalence, of () stricto and of () were amplified and sequenced. Most spp. from the Northeast ( = 115/115; 100%) and the Midwest ( = 77/80; 96.3%) were , American clade. spp. were identified in 34 of 192 (17.8%) and in 5 of 192 (2.6%) . Two and one were identified from Ohio, Illinois, and Michigan. In contrast, 156 of 261 (59.8%) spp. from the Southeast were , American clade; 86 of 261 (33.0%) were , Southern clade; 9 of 261 (3.4%) were ; and 10 of 261 (3.8%) were . Southern clade was significantly more common in Florida and less common in the upper South ( < 0.0001). One (1/242; 0.4%) from the Southeast (Kentucky) tested positive for and 6 of 242 (2.5%) were positive for . In the West, most (34/44; 77.3%) spp. were , with ( = 6) submitted from dogs in Alaska, Washington, and Oregon and ( = 4) preliminarily identified from a dog in Montana. Pathogens were not detected in any ticks from the West. Although , American clade, predominated in the Northeast and Midwest, additional spp. were found on dogs and cats in other regions and pathogens were less commonly detected. The role of less common spp. as disease vectors, if any, warrants continued investigation.