Читать книгу The Complete Book of Dog Breeding - Dan Rice - Страница 24

Dogs’ fertility (the propensity for normal pregnancy) does not seem to differ in response to its climatic seasonal environment. An extensive study of a number of breeds and cross-bred dogs showed that estrus activity (periods of receptivity of females) were identical in January and July (11.4 percent in each month). A slight reduction of estrus activity was observed in December (10.9 percent), and the rest of the months of the year saw very similar figures (6.4 to 8.3 percent). Seasonal or climatic changes seem to influence the estrous cycles of feral canine populations.