Progesterone is used to time the ovulation of the dog. Ovulation timing is commonly done for the following reasons:
- Infertility or trouble getting bred
- Shipment of chilled semen
- Implantation of stored frozen semen
- Dogs who will need c-sections (so surgery can be timed accurately)
- Travel with either bitch to stud or stud to bitch to minimize travel times
The trend of the progesterone is much more important than “the number”. We usually start testing progesterone around day 5-6 of the heat cycle. Progesterone assay are commonly done in conjunction with vaginal cytology or vagina scoping.
Dogs usually ovulate 2 days after the progesterone rises above 2. The eggs need an additional 1-2 days to mature. They stay mature for 3-4 days. This gives us a fertile period between 4-6 days after the progesterone rises above 2. Days 3 and 7 are “bookmark end” days of fertility. Below is a chart to help with interpretation:
These numbers vary tremendously between dogs, but the ovulation after going above 2 stays about the same for most dogs. However, about 20% of the dogs will not follow this schedule and are very difficult to time. LH is another hormone used to help determine ovulation in those dogs Idaho Veterinary Hospital offers same-day results on both progesterone and LH testing. Please call for details and information on our breeding packages.