Levantamento epidemiológico de carrapatos em cães assistidos em duas unidades privadas de serviço de saúde animal na Zona Oeste da cidade do Rio de Janeiro

Abstract

It evaluated the prevalence and potential risk factors for the occurrence of ticks in dogs from January 2000 to December 2014 in two private veterinary clinics, located in the West Zone of Rio de Janeiro state, Brazil. Fifteen hundred records were systematically sampled from an unknown population. Fifteen hundred records were systematically sampled from an unknown population. Statistical analysis was performed considering the outcome variable, tick presence (group 1) and positive tick + negative tick / positive hemoparasite (group 2) and the explanatory variables, sex, age, race, size, neighborhood, and clinic. An exploratory analysis was made to verify the distribution of the prevalence of ticks and their range of 95% confidence, considering all the explanatory variables for the presence of ticks. Differences in the prevalence also were testing by reason proportions test. Bivariate and multivariate analysis by logistic regression models were using to verify the relationship of the outcome of interest and their potential risk factors through the prevalence ratio (PR). The adopted modeling strategy was based on the bivariate analysis. After then, variables were selected to be included in the multivariate model. Akaike Information Criterion (AIC) were estimated to indicated the most parsimonious multivariate model. All statistical analysis was performed in the statistical package R. Of all the 1,500 records of dogs in 264 (17.60% [95% CI: 15.67, 19.52]) had the infestation by ticks in group 1 and 372 (24.80% [95% CI: 22 61, 26.98]) in group 2. Sex and age were not considered risk factors. There were differences in parasitism between races within groups 1 and 2. Males Cocker Spaniel, medium-sized and Bangu were the variables with the highest prevalence in both groups. German Shepherd race does not configured risk factor for ticks, confirmed by the most parsimonious model (PR = 1.77 [95% CI: 0.44, 07.10]). The Cocker Spaniels as well as animals living in Bangu had 7.5 [95% CI: 3.01, 18.53] and 1.7 [95% CI: 1.20, 2.32] times, respectively, more chance to be parasitized by ticks. The prevalence of hemoparasite transmitted by ticks should be considered as supplementary data for ticks epidemiological studies in dogs. This is the first study to rank the dog breeds in relation to the prevalence of parasitism by ticks.