The most successful time to mate a bitch is two days after she has ovulated, but how do you know when this is?
The only easily tested, reliable method of predicting ovulation in the bitch is a progesterone blood test. Ovulation occurs two days after the LH surge when progesterone levels are between 15 and 20 nmol/l (please note that some countries and some tests use different units to measure progesterone ie ng/ml and in that case ovulation occurs between 5 – 7 ). Most vet practices will take a blood sample, sent it to a lab and have the result the next day. This is very accurate but is not available on weekends or Bank Holidays. A premate test (in house blood test) is a useful indicator of progesterone levels, but even when carried out by well trained staff it only gives a guide to progesterone levels.
At Millhouse we now have a progesterone analyser which gives a precise result within an hour of taking a blood sample.
Even experienced breeders can have difficulty judging the best time to mate, some bitches may ovulate as early as day five of the season and some as late as day twenty five. Certain lines of bitches may ovulate early or late after the season starts and knowing this may be helpful to decide when to start testing. In general, we would recommend that you start testing progesterone levels between day five and seven after the start of pro-oestrus (vulval bleeding and swelling), and repeat the test every two or three days depending on the result.
After ovulation it takes approximately 48 hours for eggs to mature before they can be fertilised, and it takes around 12 hours after ejaculation for fresh sperm cells to be able to fertilise an egg. Luckily canine sperm cells can live for up to five days once deposited inside the reproductive tract of the bitch, so although the best time to mate is two days after ovulation, matings just before ovulation can still produce puppies. If possible, two matings (24 – 48hours apart) are recommended.
Progesterone testing is especially important if your bitch has failed to produce a litter previously and is vital when using chilled or frozen semen.
Chilled semen will only survive for 24 hours after warming, and frozen semen even less time at approximately 12 hours. So timing is vital in these cases, and to improve chances of success the sperm are usually helped on their way by placing them directly into the uterus rather than the vagina. (see TCI)