The impact of dog population management on free-roaming dog population dynamics, health and welfare

Free-roaming dogs present disease, economic and conservation risks, whilst often experiencing health and welfare problems themselves. Dog population management is widely conducted to mitigate these issues. Recent studies have highlighted the need to assess the impact of different dog population management methods in terms of their effectiveness, efficiency and sustainability. This thesis reports the impact of dog population management methods on free-roaming dog population dynamics, health and welfare. An initial systematic review was conducted, finding that most management methods are associated with a reduction in population size and risks to public health and dog welfare. Methods involving fertility control had the greatest reported effect on dog population size. A follow-up field study collected dog population and public attitude data in focal European countries (Bulgaria, Italy and Ukraine). A mark-recapture study using Pollock’s robust design was conducted to determine population size, growth, and rates of recruitment and removal for free-roaming dog populations, finding evidence for effects of sex on removal rates and survey conditions on dog detection probability. The questionnaire found associations between public attitudes and dog ownership practices with gender, religious beliefs, age, education level, reason for dog ownership, previous experience with free-roaming dogs, and country of residence.
Using the field data, a systems dynamics model was developed incorporating an interactive system of dog subpopulations to investigate the impact of population management on dog population size, welfare, and financial costs. Results show that methods incorporating both fertility control and responsible ownership have the greatest potential to reduce free-roaming dog population sizes, whilst being cost-effective and improving overall welfare. This thesis highlights the importance of identifying the causes of population increase (e.g. abandonment of owned dogs), to ensure that population management efforts create lasting change.