Babesia conradae infection in coyote hunting dogs infected with multiple blood-borne pathogens

J Vet Intern Med. 2018 Sep;32(5):1609-1617. doi: 10.1111/jvim.15233. Epub 2018 Oct 11.

Abstract

Background: Babesia conradae is an intraerythrocytic piroplasm infecting dogs in the southern United States. Ticks have been suspected, but unproven, as vectors. We identified B. conradae and other blood-borne pathogens in 2 kennels of sighthounds with a history of coyote fighting.

Objectives: To examine clinicopathologic abnormalities associated with B. conradae infection, risk factors for infection, and the prevalence of coinfections with other blood-borne pathogens.

Animals: Fifty-five Greyhounds and Greyhound mixes METHODS: Blood samples were collected from each dog for CBC, serum biochemistry panel, conventional and real-time PCR assays (Babesia spp., hemoplasmas, Ehrlichia canis, Bartonella spp., Anaplasma spp., and Rickettsia spp.), vector-borne pathogen ELISA, and immunofluorescent serology and culture for Bartonella spp and Francisella tularensis sero-agglutination test. Associations between B. conradae infection and coyote fighting, age and laboratory abnormalities were investigated.

Results: Twenty-nine dogs were PCR-positive for B. conradae. Of these, 16 were PCR-positive for other vector-borne organisms including Mycoplasma haemocanis, "Candidatus Mycoplasma haematoparvum," E. canis, and a Hepatozoon felis-like organism. Twelve of the 20 dogs tested for seroreactivity to Bartonella spp. antigens were positive, but none were seropositive for tularemia. Infection with B. conradae was associated with a history of aggressive interactions with coyotes; lower hematocrit, leukocyte count, MCHC, platelet count and serum albumin concentration; and higher MCV, MPV, and serum globulin concentration.

Conclusions and clinical importance: Babesia conradae infection should be considered in dogs with anemia, leukopenia, thrombocytopenia, hypoalbuminemia and hyperglobulinemia. As with B. gibsoni, aggressive interactions with other canids may play a role in B. conradae transmission.

Keywords: Babesia; Bartonella; anemia; mycoplasma; thrombocytopenia.

MeSH terms

  • Animals
  • Babesia / classification*
  • Babesiosis / blood
  • Babesiosis / epidemiology
  • Babesiosis / parasitology*
  • Blood-Borne Pathogens
  • California / epidemiology
  • Case-Control Studies
  • Coyotes
  • Dog Diseases / parasitology*
  • Dogs
  • Polymerase Chain Reaction
  • Risk Factors
  • Time Factors