Modeling the effect of surgical sterilization on owned dog population size in Villa de Tezontepec, Hidalgo, Mexico, using an individual-based computer simulation model

PLoS One. 2018 Jun 1;13(6):e0198209. doi: 10.1371/journal.pone.0198209. eCollection 2018.

Abstract

Surgical sterilization programs for dogs have been proposed as interventions to control dog population size. Models can be used to help identify the long-term impact of reproduction control interventions for dogs. The objective of this study was to determine the projected impact of surgical sterilization interventions on the owned dog population size in Villa de Tezontepec, Hidalgo, Mexico. A stochastic, individual-based simulation model was constructed and parameterized using a combination of empirical data collected on the demographics of owned dogs in Villa de Tezontepec and data available from the peer-reviewed literature. Model outcomes were assessed using a 20-year time horizon. The model was used to examine: the effect of surgical sterilization strategies focused on: 1) dogs of any age and sex, 2) female dogs of any age, 3) young dogs (i.e., not yet reached sexual maturity) of any sex, and 4) young, female dogs. Model outcomes suggested that as surgical capacity increases from 21 to 84 surgeries/month, (8.6% to 34.5% annual sterilization) for dogs of any age, the mean dog population size after 20 years was reduced between 14% and 79% compared to the base case scenario (i.e. in the absence of intervention). Surgical sterilization interventions focused only on young dogs of any sex yielded greater reductions (81% - 90%) in the mean population size, depending on the level of surgical capacity. More focused sterilization targeted at female dogs of any age, resulted in reductions that were similar to focusing on mixed sex sterilization of only young dogs (82% - 92%). The greatest mean reduction in population size (90% - 91%) was associated with sterilization of only young, female dogs. Our model suggests that targeting sterilization to young females could enhance the efficacy of existing surgical dog population control interventions in this location, without investing extra resources.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Cities
  • Computer Simulation*
  • Dogs*
  • Female
  • Life Cycle Stages
  • Male
  • Mexico
  • Models, Theoretical*
  • Ownership
  • Pets*
  • Population Control
  • Population Density
  • Procedures and Techniques Utilization / statistics & numerical data
  • Sterilization, Reproductive / statistics & numerical data
  • Sterilization, Reproductive / veterinary*
  • Stochastic Processes

Grants and funding

The authors gratefully acknowledge a Mathematics of Information Technology and Complex Systems (MITACS) Globalinks Award (IT05893) (to LMK) and the Canada Research Chairs Program (to ALG) for funding, as well as in-kind funding provided by Health Services of the State of Hidalgo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.