We report functional relationships between humans and canines based on observations in the village of Santa Cruz (Toledo District, Belize), emphasizing the cultural ecology of dogs in this lowland tropical rainforest setting and milpa agriculture subsistence system. Dogs pursue animals threatening field crops; they deter forest herbivores by leaving their scent along the myriad trails from the village to the milpa field plots; and they guard the homestead and foods stored there. Dogs also aid in daytime hunts for species that can be cornered. They are less useful in pursuits of fast species like deer and are protected from pursuing especially dangerous species like anteater or warri. Litter survival rates are low, and the lifespan of hunting dogs is significantly shorter than that of guard dogs due to hazards of forest pursuit. Explicit training for hunting is limited and maintenance costs are low as dogs are fed a partial ration of tortillas and otherwise scavenge for their diet. The village population of dogs appears not to be under genetic selection for hunting skills. Our results advance the comparative ethnographic study of this important domesticate; they should aid in the formulation and assessment of hypotheses about dog domestication and co-evolution with human society.