Risk factors associated with anti-Leptospira spp antibodies occurrence in dogs from Monte Negro County, Rondonia, Brazilian Western Amazon

The microscopic agglutination test was applied to 329 samples taken from 156 dogs from urban area and 173 from rural areas of Monte Negro County, Rondonia State, Brazil, to determine anti-Leptospira spp. antibodies. A survey was concomitantly done to defect eventual risk factors thru the use of logistic regression. Studied variables were age, sex, diet, management, environment, contact with other species and hunting habit. Titers :100 were detected in 27.3% (901329) of the dogs. being 23.7% (37/156) urban and 30.6% (53/173) rural dogs. The most frequent serovors were Autumnalis (22.0%), Pyrogenes (12.0%), Canicola (10.0%) and Shermani (7.5%). Dogs older than 12 months showed higher positive frequencies than younger animals (P < 0.05). Risk factor were associated with commercial food as compared to homemade food (odds ratio: 3.3; 95% confidence interval : 1.3 - 3.9; P=0.02) and associated with sex, with higher occurrence in males than in females (odds ratio: 2.3; 95% confidence interval: 1.3 - 3.9; P=0.003). It was emphasiied the serological occurrence of serovars kept and spread in nature by wild animals.