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

Abstract

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.

Occurrence of Ehrlichia canis and Anaplasma platys in household dogs from northern Parana

“…Although no relationship was observed between street access and the possibility of infection during this study, dogs from the semi-arid region of the State of Paraiba that had restricted street access were more likely to be infected by E. canis due to the greater possibility of contact with infected ticks (AZEVEDO et al, 2011). Moreira et al (2003) suggested that dogs exposed to ticks are more likely to present elevated levels of infection by E. canis. The absence of significant difference between exposure to ticks and infection in this study might probably be because all samples were collected during the winter.…”

“…These hematological alterations in this anemic disease are probably caused by the combined or isolated effects of the reactions induced by the monocyte-phagocyte system, cell lysis due to the action of the complement system, and suppression of erythropoiesis in the bone marrow are the mechanisms responsible for the table identified as anemic disease (MOREIRA et al, 2003).…”

Prevalence of ehrlichial infection among dogs and ticks in Northeastern Brazil

“…Amplification of ehrlichial DNA was attempted by nested-PCR with canine and tick DNA samples in accordance with the technique described by Murphy et al (1998). This PCR protocol consists of a general primary reaction, and nested reactions, each specific for a Ehrlichia species (E. canis, E. chaffeensis, or E. ewingii) with primers that amplify a fragment 398 pb of the 16S rRNA gene.…”

“…Canine ehrlichiosis is a tick-borne disease caused by an obligatory intracellular Gram-negative bacteria of mononuclear cells (MURPHY et al, 1998;SKOTARCZACK, 2003). Considered one of the most important infectious diseases among dogs, canine ehrlichiosis arises via Ixodidae vectors, which depend on hosts that are vulnerable to the infection as well as being climate-related.…”

“…Traditionally, both Ehrlichia canis and E. ewingii are involved in canine infections, but only the first has worldwide distribution, a reflection of the primary vector, Rhipicephalus sanguineus (RIKIHISA, 1991;BREITSCHWERDT;HEGARTY;HANCOCK, 1998a;DUMLER et al, 2001). E. ewingii is limited to the United States, but has been identified in Amblyomma americanum, Rhipicephalus sanguineus, and Dermacentor variabilis ticks (MURPHY et al, 1998), making its distribution potentially similar to that of these vectors. The main vector of E. chaffeensis ISSN 0103-846X (impresso) / ISSN 1984-2961 Full Article is A. americanum, although infection is also known to occur in D. variabilis and R. sanguineus (WALKER et al, 2004;NDIP et al, 2007;RIKIHISA, 1999;STANDAERT et al, 2000).…”