RESUMO
The present study aimed to compare different sterilization scenarios allowing the adoption of the most adequate strategy to control owned dog and cat population sizes as the official veterinary public policy for animal control in an urban area of Campinas municipality, Brazil. To achieve this goal, the vital parameters of the owned pet population were measured in a neighborhood of Campinas called Jardim Vila Olimpia through questionnaires used in two census studies performed in February 2012 and June 2013. Different hypothetical sterilization scenarios were compared with the scenario of a single sterilization campaign performed in the study area between the census studies. Using a deterministic mathematical model, population dynamics were simulated for these different scenarios. We have observed that for both owned dogs and cats, the impact on the population size achieved by a single sterilization campaign would be diluted over the years, equating to the impact achieved by the usual sterilization rate practiced before the sterilization campaign yearly. Moreover, using local and global sensitivity analyses, we assessed the relative influence on animal population evolution of each vital parameter used in the mathematical models. The more influential parameters for both species were the carrying capacity of the environment and sterilization rates of males and females (for both species). We observed that even with sterilizing 100% of the intact animals annually, it would not be possible to obtain proportions greater than 86% and 88% of sterilized dogs and cats, respectively, after 20 years due to the high introduction of new intact animals. There is no public dog and cat sterilization service in place in the city, and sporadic and local sterilization campaigns are performed with a prior communication to the owners to bring their animals to be sterilized in a selected veterinary facility. If a sterilization campaign was performed annually in the study area, it would have the most favorable cost effectiveness ratio after 20 years compared to the scenarios of 50% and 100% sterilization of intact animals annually. These results allowed the veterinary public policy stakeholders to make decisions based on scientific evidence to implement adequate control of dog and cat populations in urban areas, aiming to reduce zoonosis transmission to humans and other problems associated with uncontrolled animal populations.
Assuntos
Orquiectomia/veterinária , Ovariectomia/veterinária , Política Pública , Animais , Brasil , Gatos , Cidades , Cães , Feminino , Masculino , Modelos Teóricos , Orquiectomia/legislação & jurisprudência , Orquiectomia/estatística & dados numéricos , Ovariectomia/legislação & jurisprudência , Ovariectomia/estatística & dados numéricos , Propriedade , Densidade Demográfica , Dinâmica PopulacionalRESUMO
Bats are less vulnerable to forest fragmentation than any other mammal, and for that reason, some species can disperse to peri-urban or urban areas. Insectivorous bats are abundant in urban areas due to the density of artificial roosts and insects attracted by city lights. Inter-species transmission of the rabies virus between bats can occur, and this is the most probable mechanism of virus circulation in bat populations. Bats can also transmit the rabies virus to other mammal species, like dogs and cats. With the halt of dog and cat vaccination campaigns in 2010, the importance of rabies surveillance in bats has increased in Brazil. A cross-sectional study performed in Campinas, Sao Paulo State, using data from the passive surveillance system for bats showed that rabies-positive bats from the families Molossidae, Phyllostomidae and Vespertilionidae were found in a peri-urban area. In these areas, dog and cat emergency vaccination (vaccination blockage) was recommended after the halt of the massive vaccination campaign in 2010. This control strategy was able to increase the proportion of vaccinated animals around a critical value of 50% and even with a higher probability of infectious contact between bats and dogs or cats in the vaccination blockage areas, no dog or cat rabies case was observed, evidencing the importance of the implementation of strategic rabies control measures in this new epidemiological scenario.