Estimation of the dog and cat population in the State of Sao Paulo

Objective To estimate the total dog and cat population with owners in order to enable better planning of the control actions against diseases involving these animals. Methods The study was carried out in the non-metropolitan regions of the State of Sao Paulo, Brazil, from May to December 2002. Forty-one municipalities and 100 census tracts were surveyed. These were selected by probabilistic stratified cluster sampling in two stages. The strata were formed by grouping the municipalities according to their populations and living conditions. The Pasteur Sao Paulo Technique was used to obtain data on the canine population. This technique was developed to estimate and classify dogs according to their degree of dependence and restriction. Results Almost 53% of the 20,958 households visited owned a dog, and the average was 1.6 dogs per household. A total of 4,624 cats were found, concentrated in 12.6% of the households. The results indicate a dog/inhabitant ratio of 1:4.0 and a cat/inhabitant ratio of 1: 16.4. Conclusions The animal/inhabitant ratios were much higher than expected. Incorporation of these ratios into evaluations of the vaccination campaign against rabies has revealed more realistic coverage patterns, thus leading to renewed discussion of the vaccination targets for municipalities. An association was observed between the size of the municipality or its inhabitant's living conditions and the level of restrictions on dogs.