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Oklahoma State University
Center for Veterinary Health Sciences

Healthy Animals - Healthy People

Krull-Ewing Laboratory

Dr. Susan Little's research interests focus on the natural history and transmission dynamics of tick-borne diseases with a goal of elucidating the mechanisms that conspire to allow maintenance of disease agents in reservoir hosts and tick vectors and transmission of those agents from ticks to people and animals. Other professional interests include zoonotic parasites, particularly those transmitted from pets to people

View Dr. Susan Little's Full Profile.

Current Research Projects

Our research program focuses on the natural history and transmission dynamics of tick-borne diseases with a goal of elucidating the mechanisms that conspire to allow maintenance of disease agents in reservoir hosts and tick vectors. We concentrate our efforts on tick-borne disease systems important for canine and/or human health. Active projects are ongoing in a variety of pathogen-tick-disease systems, including:

  • Amblyomma americanum / Ehrlichia chaffeensis and Ehrlichia ewingii / ehrlichiosis
  • Amblyomma americanum / STARI
  • Rhipicephalus sanguineus / Ehrlichia canis / canine ehrlichiosis
  • Amblyomma maculatum / Hepatozoon americanum / American canine hepatozoonosis
  • Ixodes scapularis / Borrelia burgdorferi / Lyme borreliosis

Recent Publications

Johnson EM, Panciera RJ, Allen KE, Sheets ME, Beal JD, Ewing SA, Little SE. 2009. Alternate pathway of infection with Hepatozoon americanum and the epidemiologic importance of predation. J Vet Intern Med. Aug 26. [Epub ahead of print]

Murdock JM, Yabsley MJ, Little SE, Ramaswamy C, O’Conner T, Caudell JN, Huffman JE, Langenberg JA, Hollamby S. 2009. Distribution ofBorrelia lonestari and Borrelia burgdorferi antibodies in white-tailed deer (Odocoileus virginianus) populations in the eastern United States. Vector Borne Zoonotic Dis. Epub ahead of print.

Little SE, Allen KE, Johnson EM, Panciera RJ, Reichard MV, Ewing SA.2009. New developments in canine hepatozoonosis in North America: a review. Parasites and Vectors. 26(2):1-5.

Little SE, Johnson EM, Lewis D, Jaklitsch RP, Payton ME, Blagburn BL, Bowman DD, Moroff S, Tams T, Rich L, Aucoin D. 2009. Prevalence of intestinal parasites in pet dogs in the United States. Vet Parasitol. 166(1-2):144-52.

Reichard MV, Meinkoth JH, Edwards AC, Snider TA, Kocan KM, Blouin EF, Little SE. 2009. Transmission of Cytauxzoon felis to a domestic cat byAmblyomma americanumVeterinary Parasitology. 161(1-2):110-5.

Yeagley TJ, Reichard MV, Hempstead JE, Allen KE, Parsons LM, White MA, Little SE, Meinkoth JH. 2009. Detection of Babesia gibsoni and the canine small Babesia sp. “Spanish Isolate” in confiscated pit bull terriers.JAVMA. 235(5):535-9.

Johnson EM, Allen KE, Panciera RJ, Ewing SA, Little SE. 2009.Experimental transmission of Hepatozoon americanum to New Zealand White rabbits (Oryctolagus cuniculus) and infectivity of cystozoites for a dog. Vet Parasitol. 164(2-4):162-6.

Reichard MV, Roman RM, Kocan KM, Blouin EF, de la Fuente J, Snider TA, Heinz RE, Massung RF, West MD, Little SE. 2009. Inoculation ofAnaplasma phagocytophilum Ap-VI and NY-18 strains in white-tailed deer (Odocoileus virginianus) and microscopic demonstration of the rickettsia in acquisition fed Ixodes scapularisVector Borne Zoonotic Dis. 9(5):565-8.

Bowman DD, Little SE, Lorentzen L, Shields J, Sullivan M, Carlin E. 2009.Prevalence of vector-borne diseases in dogs in the United States: analysis of a comprehensive national database. Veterinary Parasitology 160(1-2):138-48.

Drake D, Carreno AD, Blagburn BL, Little SE, West MD, Hendrix CM, Johnson CM. 2008. Proliferative sparganosis in a Florida dog. JAVMA.233(11):1756-60.

Li Y, Wang C, Allen K, Little S, Ahluwalia S, Gao D, Macintire DK, Blagburn BL, Kaltenboeck B. 2008. Diagnosis of canine Hepatozoon spp. infection by quantitative PCR. Veterinary Parasitology. 157:50-8.

Allen KE, Li Y, Kaltenboeck B, Johnson EM, Reichard MV, Panciera RJ, Little SE. 2008. Diversity of Hepatozoon species in naturally infected dogs in the southern United States. Veterinary Parasitology. 154: 220-5.

Johnson EM, Allen KE, Panciera RJ, Little SE, Ewing SA. 2008. Infectivity of Hepatozoon americanum cystozoites for a dog. Vet Parasitol. 154: 148-50.

Yabsley MJ, Murphy SM, Luttrell MP, Little SE, Massung RF, Stallknecht DE, Conti LA, Blackmore CG, Durden LA. 2008. Experimental and field studies on the suitability of raccoons (Procyon lotor) as hosts for tick-borne pathogens. Vector Borne and Zoonotic Diseases. 8:491-503.

Yabsley MJ, Loftis A, Little SE. 2008. Natural and experimental infection of white-tailed deer (Odocoileus virginanus) with an Ehrlichia sp. closely related to Ehrlichia ruminantiumJournal of Wildlife Diseases. 44: 381-7.

Johnson EM, Allen KE, Breshears MA, Panciera RJ, Little SE, Ewing SA.2008. Experimental transmission of Hepatozoon americanum to rodents.Veterinary Parasitology. 151(2-4): 164-169.