There are three stages to labor. During the first stage the cervix dilates and contractions begin. Your female will be uncomfortable, restless, pace and pant. This lasts 6-18 hours. During the second part of labor, your female's contractions begin in ernest. Her water breaks and puppies are delivered usually after 10-30 minutes of pushing. All puppies are born during this stage. The third stage of labor is after all pups have been delivered and is when a dog still has small contractions to expell fluids and/or placentas from the uterus.
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A dog's gestational period (pregnancy) is approximately 63 days from breeding. One way of knowing when your dog with have her puppies is to take her temperature twice daily at the same time each day as her due date gets close. Keep a record of this.
A dog's normal temperature is between 101-102.5F degrees. Her temperature may rise and fall during this time, but once her temperature falls below 99 degrees, she should go into labor in the next 24 hours. The temperature drop is due to a reduction in serum progesterone levels and signals that the dog will start labor within 24 hours. Since your dog appears to have a temperature under 99F for several days, I would be sure you have a new thermometer to be sure it is accurate. In addition, I would recommend a digital one that can give you the temperature quickly and has an audible or visual signal that the process is complete. Many times an older thermometer might not be accurate or an owner may remove the thermometer early or not have it inserted the inch that is needed to get an accurate reading.
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You may also notice her breasts swelling during this last week of pregnancy and some milk leakage. Dogs will usually become restless and increase their digging and nesting behavior during the last week. You will notice an increase in her panting as well as a mucous discharge. You may also notice some abdominal contractions or rippling as her time grows closer. Do not be surprised if your dog is very restless and vomits as few times during this last week. Mine always do this
Once your dog's temperature has dropped, please do not leave her alone in case of complications. As she enters actual labor you should be able to see her contractions and most dogs will begin looking at their hindquarters. An increase of licking of the genitals is normal before and during labor. Be sure and have an emergency Vet's phone number readily available just in case of an emergency during the birthing of the puppies.
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Some other signs that my dogs always seem to exhibit are lack of appetite, frequent urination and frequent small, runny bowel movements in the day before labor starts. Frequently my dogs will start looking at their rears when the first real contractions start. Puppies usually become real quiet the day before labor begins as well.
Since you can not know a dog is pregnant until they are almost a month pregnant, perhaps your dates are a little off. They are pregnant about 63 days from the first breeding tie. However, most vets will not induce labor until they are a week overdue. So for right now, see about getting a second temperature reading with a new thermometer and see if that is the problem. Her actions do not point toward labor tonight.
I hope you find this information helpful.