Molecular diagnosis of Ehrlichia canis in dogs with clinical signs, hematological and biochemical changes in the Municipality of Ilhéus, Bahia, 38(4):345-352

  • Josiane Moreira Rocha
  • Fabio Santos Carvalho
  • Haniel Cedraz Oliveira
  • Renata Santiago Alberto Carlos
  • Paulo Luíz Souza Carneiro
  • George Rego Albuquerque
  • Amauri Arias Wenceslau


ABSTRACT. Rocha J.M., Carvalho F.S., Oliveira H.C., Carlos R.S.A., Carneiro P.L.S., Albuquerque G.R. & Wenceslau A.A. [Molecular diagnosis of Ehrlichia canis in dogs with clinical signs, hematological and biochemical changes in the Municipality of Ilhéus, Bahia.] Diagnóstico molecular de Ehrlichia canis em cães com alterações clínicas, hematológicas e bioquímicas no município de Ilhéus, Bahia. Revista Brasileira de Medicina Veterinária, 38(4):345-352, 2016. Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Santa Cruz, Rodovia Jorge Amado, Km 16, Salobrinho, Ilhéus, BA 45662-900, Brasil. E-mail:

The objective was to identify DNA of Ehrlichia canis in dogs with clinical and hematological or consistent with infection, and to identify possible risk factors for infection in the Municipality of Ilhéus, BA, an endemic area to infection. 558 were collected blood samples from dogs. These samples were divided into vials with and without anticoagulant made to research of blood smears for direct research on the blade. While the animals were submitted thorough assessment to clinical test, ticks were collected from dogs. The blood with anticoagulant was used to perform complete blood count and molecular tests for the detection of E. canis and without anticoagulant for biochemical examinations of Urea, Creatinine and ALT. Screening was held before molecular analysis and research of blood smears in blade, where the animals selected with hematological, biochemical and clinical signs suggestive of infection were selected. After the screening, 297 dogs were selected for the detection by molecular analysis and research of blood smears in blade Ehrlichia spp. and E. canis. Of animals evaluated by molecular methodology 85.52% (254/297) were positive to the genre and 80.13% (238/297) were positive to the species E. canis by Nested-PCR. In 28.16% (84/297) of animals was found infection in peripheral blood smear and all were positives by the Nested-PCR. Animals positive for E. canis, showed cachexia in 25.39%, pallor in mucous membranes in 17.46%, petechiae in 15.87% and had epistaxis in 1.58%, and other 38.09% (24/63) presented more than one of the concomitant changes. The animals with clinical changes were statistically significant (p = 0.02) relative to the negative for E. canis. With regards to Hematologic changes in 80.13% of the dogs were infected by E. canis, these being statistically significant (p = 0.001). Animals with anemia showed statistical significance (p = 0.001), however, there was no significance in thrombocytopenic dogs (p = 0.28). When evaluating animals with anemia associated with platelet count less, the results were significant statistically (p < 0.005). It was found ticks on 14.14% of screened animals and were not statistically significant (p > 0.05), but 48.82% (145/297) animals insecticide control before the collection, and that was significant (p = 0.003). With respect to biochemical evaluation results were not statistically significant (p > 0.05) for the infection. They detected by molecular analysis at 19.04% ticks were infected with E. canis, the total of 42 samples of infected dogs. The region has high rates of infection by E. canis and animals of this study possibly are in the chronic phase of the infection in the Municpality of Ilheus, BA.