Читать книгу The Complete Book of Dog Breeding - Dan Rice - Страница 22

The time interval between periods of receptivity of canine females is termed the interestrous period. It varies greatly between breeds and between individuals within a breed. One lengthy study found the interestrous interval in German Shepherds to be as short as 149 days, and in Boston Terriers to be as long as 242 days. Bassets, Beagles, Cockers, Pekingese, and Poodles fell in between.

German Shepherds and Rottweilers sometimes have estrous cycles of four months or less. Bitches that demonstrate interestrous intervals of less than 130 days may not have ample organ repair and preparation time during anestrus. Infertility is occasionally seen in those animals, and hormone treatment can often be used to lengthen their interestrous periods.