Like all dogs, an early sign of labor in Yorkshire terriers is a lowered temperature and lack of interest in food that occurs within 24 hours of the actual whelping. Contractions may cause the Yorkie to show signs of abdominal pain like whining, pacing and licking.
One of the first obvious signs of labor is the appearance of a gray, fluid-filled sac from the dog's vulva. This is the amniotic sac. She may lick at it or otherwise tear it open, which is normal. This is the first part of delivery and the actual puppies are close behind. Once this sac has been ruptured or fully pushed out, the puppies should come within minutes. After puppies begin to appear, labor can last for a long time. Periods of up to two hours are normal between puppies. However, if the bitch appears to still be pushing but no puppies have appeared in that time, a veterinarian should be called. After the last puppy is born, the placenta passes as well. Once the placenta appears, labor should be completed.
Yorkies should give birth within 70 days of conception, and should not remain in labor for more than 24 hours without birthing puppies. If the pregnancy is continuing too long, emergency veterinary assistance is necessary.