Bitches have their first estrus (also know as season or heat) after six months of age, although it can occur as late as 18 months to two years of age.
Bitches have their first estrus (also know as season or heat) after six months of age, although it can occur as late as 18 months to two years of age.
一些在母犬六个月龄后就会有第一次发情，有些则会迟至18个月甚至两岁。