As your bitch approaches the time when she is coming into season, her progesterone level slowly begins to raise. The first sign of your bitch is in season is usually bright red blood, other changes have started in her body as well. In order to prepare her for a natural breeding the delicate mucous membranes in her vagina have started the process of cornification . This means a different type of skin cell is growing and layering inside the vagina.
Females come into season around six to nine months of age. Some larger breeds may start between six to fourteen months of age. Once the bitch has come into season and thatís the beginning of puberty. In the same way that humans are not ready for parenthood at the onset of puberty, neither are dogs. With dogs you should wait until after the second heat which would be after her 1 year birthday. With larger dogs you should wait till after the second birthday because their bones are still growing until their second birthday.
If you have decided to breed your bitch. Study, join message boards, ask other breeders, talk with your vet.
Some bitches are ready for breeding by the 7th day or so and then others may not be ready until day 16. Some breeders have made a practice of breeding on days 10, 12 and 14 and that makes a lot of sense. But having scientific knowledge we begin to understand that the bitches ovulate on the average about 9 to 10 days after the first signs of her season. We also must understand that the long life span of the sperm. Knowing that the sperm live in the reproductive tract for 5 to 7 days and the eggs at least 4 to 5 days the day. This overlap of the long lived sperm to viable egg was what made days of 10, 12, and 14 a successful breeding.
Your bitch drops her eggs when her progesterone level is around 5ng/ml. After she ovulates the progesterone level will rise and start to drop after the eggs are either fertilized or dead. If they are fertilized she will need to keep her progesterone level around 5 through the 9 weeks of gestation in order to stay in whelp. You may have a bitch have a lost of litters around 50 day due to the progesterone level has drop. If this has happen to you ask your vet to check her levels and if they are low they can give you supplemental progesterone and instruct you in the use.
After your bitch has ovulated her eggs will take 2 to 3 days to ripen and live at least another 2 days. If you breed her two days prior to when she ovulates the sperm will be alive and will fertilize the eggs when they have ripened. Some times your bitch may stand and allow breeding 3 sometimes 4 days before ovulations. Then some will only allow a breeding 12 days after ovulation. In this case with such a late breeding, no pups were born.
The main points itís all numbers and facts that are firm and set in stone.
Sperm is viable for at least 5 to 7 days
Bitches ovulate when their progesterone level reaches 5ng/ml.
The eggs live for around 4 to 5 days.
If you are planning a breeding with chilled or frozen sperm you will want to know the day of ovulation in order to produce a litter of pups.
If you are going to have your bitch shipped out for breeding or the sperm shipped in timing is critical. If you have kept careful records, you may have a good ideal when your bitch is ready or about to come into season.
If you know the time is coming for your bitch is coming into season, you should make sure she is up to date on vaccines and de worming. You may even want to have your vet do a prenatal check up. Talk with your vet about her general over all health. Sometimes what we want may not be the right thing for your bitch. Talk with your vet about taking x rays of your toy size bitches to make sure she will be able to have puppies with out a c-section. Your vet may say go ahead and breed her and have x ray done around 50 days after breeding so if a c-section is needed they can set up the c-section during normal office hours. I have had two females have c-sections after hours. One time the price was 488.00 the other time at a 24 hour Vet ER was over 1200.00. Talk with your vet about what they will charge after hours and if you donít have the money think about saving the money up first before you breed your bitch. To wait another 6 or 12 months to make sure your bitch will get the best care is better for you and her.
Your males will know well before you do that your bitch is coming into season. Once you see red blood( which if you have a bitch thatís real clean you may miss the first few days) you can take her into your vet for a vaginal swab to look at the skin cells under a microscope. If there are many normal looking vaginal skin cells, the vet will know that the cornification has started or just beginning. Your vet may want to draw blood for a progesterone test.
Most breeders will not have to take this visit to the vet but if you are having your bitch A.I. With sperm that has been shipped you will want to know to make sure the day of ovulation.
When you know your bitch has ovulated due to her progesterone level has hit the level of 5ng/ml you can now get to the business of breeding. If you are doing a natural breeding, you can let the bitch to be with a stud and your can accurately predict the day of birth. Your litter will arrive on days 62 to 64 days after the progesterone is 5 ng/ml. Your puppies will be born 63 days after the eggs are released.
When will a litter be due?
The day that the egg was released is the first day of gestation. Not the day it was fertilized. NOT the day the bitch was bred. The puppy began its 63 day journey to birth from the day the egg was released. Some breeders may tell you their litter was born at 67 daysÖ No it was born on day 63. The clock starts when the egg is released not the breeding. Some may even tell you their litter were premature because they were born at 57 days.. No they were born on the 63 day after ovulation. Okay to make it clear , say your bitch ovulated on Aug 4th. Her pups will be born 63 days. They will be born Oct 6th. Your stud bred her on Aug 1st , three days she ovulated. You count from that day and she would be due Oct 3rd. So when your pups are born Oct 6th you will say they were born lateÖ No they were born on time due to the time the egg was ready.
Another myth is that when eggs are released. Some say eggs are released on one day and then some more the next day and following day, this would account for having smaller pups from the days of release. This is far from the truth. Every time a bitch has a litter the placenta has been attached in a circle around the puppy. When the placenta comes off the puppy at birth it leaves some mild scarring. So when the next egg happens to be unlucky and picks the same spot were the scarring is they will be smaller due to they simply did not receive as much nutrition as the first puppy did.
So what have we learn:
Clocks start clicking the day the egg is released, not the time of breeding.
Puppies are born on the 63rd day.
All eggs are released at the same time.
No such thing as runts or premature pups, they are small due to implantation site in the uterus.
Large pups are not overdue pups but they just had great implantation site in the uterus.
Pups are born 63 days after ovulation not the day of breeding.