Canine ecology and socioeconomic factors associated with dogs unvaccinated against rabies in a Mexican city across the US-Mexico border.

A cross-sectional study was conducted to identify ecologic and socioeconomic factors associated with dogs unvaccinated against rabies in Mexicali, the capital city of Baja California, Mexico (located across the US-Mexico border). A total of 1100 households were selected by random sampling from a list of all 180,000 households. A questionnaire was filled in during a personal interview with the household head or another adult person to gather information of epidemiological interest (such as canine ecology, social and economic factors that might influence owners' decision to allow their dog to be vaccinated). There were 910 dogs identified. The human-to-dog ratio was 4.3:1. The male-to-female dog ratio was 1.5:1. Out of 791 dogs > or = 3 months old, 577 (73%) were classified as vaccinated against rabies. Most dogs (95%) were not spayed. Neighborhood dogs had 25 times higher risk of nonvaccination compared to dogs owned by a family. Dogs 3-11 months old had three times higher risk of nonvaccination compared to dogs > or = 1 year old. Dogs that were obtained as a gift, born at home or found had two times higher risk of nonvaccination compared to dogs that were reportedly purchased. Crossbred dogs had 1.5 times higher risk of nonvaccination compared to purebred dogs. The canine-ecology structure is similar to that in regions were rabies is endemic.