Retrospective study (1998-2001) on canine ehrlichiosis in Belo Horizonte, MG, Brazil

The present work describes a retrospective study of clinical cases of ehrlichiosis in dogs examined from March 1998 to September 2001. From the clinical records with laboratorial confirmation of Ehrlichia canis or E. platys infections, the following parameters were analyzed: demographic aspects (age, race, sex, period of the year and origin), clinical characteristics (body temperature, exposure to ticks and clinical signs), and hematological characteristics (blood cell counts and type of infected cell). A total of 194 clinical records were analyzed, from which 31 animals were infected with E. canis and 21 animals with E. platys. The number of cases of canine ehrlichiosis increased considerably from the year 2000 onwards, and 24.4% of the cases occurred in 13- to 24-month-old animals, in different urban and per-urban regions of the municipality of Belo Horizonte. The most frequent symptoms were fever, anorexia, apathy, abdominal pain, lymphadenopathy and dispnea. Regarding hematological alterations, 70.3% of the animals presented anemia, 50% presented thrombocytopenia and 30% leukopenia, and most E. canis morulae were seen in monocytes. The results point to the importance of canine ehrlichiosis, as 35.9% of the dogs with suspected hemoparasitic diseases were infected with Ehrlichia canis or E. platys.