data used for population dynamics of stray dogs. Karaj, Iran.

The domestic dog (Canis familiaris), often referred to as "man's best friend," is a charismatic species that has long provided numerous benefits to humans and holds the distinction of being the first animal domesticated by humans. However, due to population explosion and the unregulated release of dogs, the issue of stray dogs has become a global concern—and Iran is no exception. This study presents the first comprehensive census and ecological analysis of stray dogs in Karaj, Iran. Using field surveys conducted across 35 blocks and following the WSPA methodology, the stray dog population was estimated at approximately 7,459, with a calculated environmental carrying capacity of 68,895. Key vital rates—birth, death, survival, and growth—were used to model population dynamics through the Leslie matrix. Projection scenarios indicated that a 75% sterilization rate was the most effective non-lethal control method over a 50-year period, whereas euthanasia, while yielding rapid results, raised significant ecological and ethical concerns. The findings emphasize the critical role of uncontrolled human support in increasing the carrying capacity and accelerating population growth. This study highlights the urgent need for evidence-based, socially informed management strategies to reduce ecological and public health risks.