Seroprevalence and Traceback of Animals Suspected of Carrying Ehrlichia canis, in Dogs Attended in Veterinary Clinics in Mexicali, Baja California, Mexico

A cross-seccional study was carried out in order to estimate the seroprevalence of antibodies against Ehrlichia canis as well as track patients suspected of carrying the disease. A total of 384 blood samples obtained from canine patients of 38 veterinary clinics in the urban area of Mexicali, Baja California, Mexico were randomly collected during 23 months and analyzed with ELISA Helica biosystems commercial kit. A Traceback was carried out by doing a follow-up of 20% of the dogs that were suspected of the disease. It encompassed a revision of their medical record as well as serum analysis. Seroprevalence found reached 21.6% (83/384). From the 20% of suspect cases (15/75) the 80% (12/15) developed signs of the disease between samplings. Of these, 67% (8/12) were treated for E. canis, which resulted in 75% (6/8) being negative in their second sample and 25% remaining as suspected of the disease. All dogs that showed signs of the disease and did not receive treatment (3/12) became positive to E. canis in their second sample. Taking into account seroprevalence and the percentage of animals suspected of carrying the disease, at least 40% of the total canine population in the city out been in contact with the bacteria. Taking account of tracking parameters for suspected individuals the prevalence obtained in this study could underestimate the real seroprevalence of Canine Monocytic Ehrlichiosis (CME) in this region. As the disease is a zoonosis it is necessary to estimate the risk factors for its presence. Future studies that include molecular biology are required in order to determine the presence of the etiological agent as well as the detection of other Ehrlichia species that show cross reaction with E. canis.