SEROPREVALENCE OF ANTI-EHRLICHIA CANIS ANTIBODIES IN DOGS WITHOUT A HISTORY OF TICK INFESTATION IN CASCAVEL/PARANÁ

Abstract

Canine monocytic ehrlichiosis is an infectious and contagious disease that affects dogs worldwide. It is caused by the bacterium Ehrlichia canis, which is transmitted by the tick Rhipicephalus sanguineus during blood feeding. This bacterium is a gram-negative, obligate intracellular organism with tropism for mononuclear cells. Ehrlichiosis is a multisystemic disease and is divided into acute, subclinical, and chronic phases. Clinical signs are variable, and the most common hematological findings include anemia, leukopenia, and thrombocytopenia. Diagnosis is based on clinical history, physical examination, hematological test results, and the presence of the tick vector on the animal, which is essential for confirmation. This study aimed to detect antibodies against E. canis in dogs that, according to their owners, had no known history of tick exposure or prior diagnosis of the disease. Blood samples were collected from 60 dogs treated at the Veterinary Clinic of Centro Universitário UNIVEL, in Cascavel, and were stored and processed for testing using the ImmunoComb Ehrlichia Canis IgG® kit, following the manufacturer’s instructions. The results showed that only 15% of the animals tested positive for anti-Ehrlichia canis antibodies, despite the absence of compatible clinical signs or history. Among the seropositive dogs, 88.88% had owners who reported that the animals had weekly access to the street. Additionally, findings from other studies conducted in western Paraná were reviewed, reinforcing the regional prevalence of E. canis and the importance of effective vector control.