Dalla Villa, P., Kahn, S., Stuardo, L., Iannetti, L., Di Nardo, A., & Serpell, J. A. (2010). Free-roaming dog control among OIE-member countries. Preventive Veterinary Medicine, 97(1), 58–63. https://doi.org/10.1016/j.prevetmed.2010.07.001

Questionnaire survey of 81 state veterinary services asking for their methods and motivations for free-roaming dog control. 61% described killing/euthanasia as part of official policy, 30 of these countries described this as the only method of control used for free-roaming dogs.