When Your Dog Pregnancy - Everything You Need to Know About Dogs and Pregnancy Preview: Dog pregnancy guide Dogs have a strong breeding drive - as anyone who's owned an un spayed female dog will know. Here, I'll go over everything involved in dog pregnancy (aside from conception!) starting from the bitch in heat, through when the puppies can be adopted out. Dog Pregnancy - Bitch in Heat First, you don't want to breed a female during her first heat, or anyway, not until after she is a year old. Allowing dog pregnancy before this, will result in stunted growth. A bitch will go in heat one or two times per year. Heat lasts about three weeks, and during this time a bitch can be bred with more than one male. Heats can be anywhere between six and nine months apart... And BUY this book for more!