Dog Breeding – When to Breed

The most common cause of an unsuccessful mating is bad timing. Many dog owners do nothing more than count the days in a cycle. They attempt to breed on the 10th through the 14th day of the heat cycle. But, as noted earlier, each female is an individual with her own breeding timetable – a timetable that can vary according to the lengths of proestrus and estrus. Ovulation cannot always be predicted just by counting the days of the heat cycle. Furthermore, counting will not be accurate if you miss the early signs of heat or if your bitch shows very little evidence of being in heat.

Fortunately, nature provides a safety factor: Fresh sperm are able to survive for up to seven days in the female oviducts. An offsetting factor is that eggs must mature in the oviducts for three days before they can be fertilized. This still leaves a window of several days before and after ovulation for successful breeding. In fact, the peak of female fertility occurs three days after ovulation.

There are reports of bitches being bred as early as the fourth day and as late as the 21st day of the heat cycle – and still conceiving a litter. When the heat cycle is this atypical, a combination of vaginal cytology and progesterone measurements can be used to determine estrus and predict the time of ovulation.

Multiple breedings are more likely than a single breeding to produce pregnancy, and may even have an influence on the size of the litter. Accordingly, most veterinarians recommend breeding a bitch every other day (or every third day) for as long as she remains in standing heat. If, for any reason, a bitch cannot be bred more than once, consider timing that breeding using progesterone assays to predict the exact time of ovulation. Using hormonal assays to determine the best time to breed is especially important if you are using fresh-shipped semen or frozen semen.