There are various reasons why dog owners purposely breed their Labrador Retrievers. One reason is that their dog is up to breed standard and they want to produce a litter. Some dog owners want to improve the breed. In some instances unknown to the owner, breeding may also took place despite that dogs are carefully confined when they are in season. No matter what the reasons are, it is important to know the signs if your Lab is in the family way.

A female dog can only become pregnant if she is bred during her heat cycle. Canine cycle, referred as estrous cycle has four stages. The first stage is proestrus in which the female dog is attractive to males but not receptive to them. This stage generally lasts six to eleven days. This stage has already ended when the dog becomes receptive to the male and will stand to be bred. The next stage is the estrus, the actual fertile stage in which the female dog is now receptive to male. This stage lasts five to nine days. This stage has ended when the female is not receptive to the male anymore. The third stage is the diestrus, a non-receptive time and the last stage of the estrous cycle is the anestrus in which no ovarian activity took place.

Dog pregnancy generally lasts 60-65 days. Early signs of pregnancy in dogs include loss of appetite, sudden decrease in activity, nipple growth and behavioral changes. As the pregnancy progresses, further signs occur. Three to four weeks into the pregnancy, you will notice an increase in appetite and weight gain by one month. Around five weeks, your dog's nipple will develop and she will begin to look broader. Increase in abdomen size can be seen and uterine swelling around the placental sites that feels like firm and discrete lumps exist. During the last few weeks of pregnancy, puppy movement can be felt and milk production begins.

Dog pregnancy can also be detected through x-rays, ultrasound or blood test. Blood test can be done by a veterinarian 30 days after being bred. In some cases, a female dog will display signs of dog pregnancy without actually being pregnant. That is why it is important to visit your veterinarian to confirm the pregnancy and that proper care will be given. Dog owners should always remember that their pregnant Labrador Retrievers need special care to make sure that they are ready when the time comes.