"Signs of whelping include restless behavior, loss of appetite and temperature change. The mammary glands expand and milk appears in the teats."
Just before whelping your dog's mammary glands will increase in size and milk will appear in the nipples.
Signs of Whelping - 24 Hours Before Birth
Your dog will start to rearrange the whelping box in preparation for the pups.
Signs of Whelping - 12 Hours Before Birth
Start to take your dog's rectal temperature 2 to 3 days prior to the expected birth. Approximately 12 hours before the pups are born your dog's (a female pregnant dog is called a bitch) temperature may drop below 100 from the normal range which is between 100 to 102. This does not happen in all cases. Your dog may also lose her appetite.
The first set of contractions last for approximately 6 to 12 hours. From this stage the uterus will contract and push the puppy into the uterus. The uterus then contracts pushing the pup against the cervix. When the cervix becomes completely dilated the pup which is enclosed in a water bag moves through the vagina. You will see the bag appear to come through the vulva. You might see the water bag first, although usually the pup is seen. It is normal to see green fluid which is the natural fluid that surrounds the pup.
Signs of Whelping - Labor
At the first stage of labor your "bitch" will look like she is panting, hiding, shivering, straining, acting restless or in some cases she may even vomit. Other signs include digging outside and scratching furniture such as the bed. Water may appear from a broken water bag. You might see vaginal discharge that has streaks of blood. Contractions should begin which produce the first pup within 2 hours.
Birth take place either standing or lying down. The mother will know to instinctively remove the placenta covering the pup and bite off the umbilical cord. The puppy should find the mom's teat and begin to drink. You can coax the puppy in that direction.
Afterbirth will be expelled through the birth canal for each puppy. be sure to count each since if any stay behind inside the mom they could cause infection.
Note that the room where puppies are born should be at 85 degrees during the first week and 80 degrees the second week going down to 72 degrees at week 6. If your dog insists on giving birth outside the box, move the pups to the box as soon as possible.
If any of these situations occur be sure to contact your veterinarian:
* Gestational period of longer than 70 days for a pregnant bitch.
* Your dog is pushing for more than 4 hours with no puppies being born
* A puppy is only partially out of the mother for 20 minutes or more
* You see water from the water bag breaking, but the puppies are not born within 12 hours.
* 2 hours go by between giving birth to puppies
* Signs of pain with your dog either crying, biting or licking the vulva* You see blood or smell a bad odor
Problems include contractions that are too weak to deliver the pups. Your veterinarian can intervene to improve the chances of a normal delivery.
Collins Complete Dog Owner's Manual
Dog Owner's Home Veterinary Handbook