Sometimes we only get one chance at a breeding, other times we have the flexibility to try again if it doesn't work out. In either case having a successful breeding can make a huge impact on a breeding program. Many things are at play when it comes to the success of a breeding, in this post we will talk about proper ovulation timing.
Before we can pinpoint ovulation we should know what hormones are at play in the process. First we have estrogen, this hormone is vital for preparing the reproductive tract for breeding as it thickens the membranes in the vagina and commences the menses (bleeding), this can range in span from 1 day to 21 days in length. The next important hormone is LH (luteinizing hormone) as it triggers ovulation to occur. The LH surge can last anywhere from 24-48 hours so it can easily be missed if one is not doing daily blood draws. The third hormone, which is of the most interest to us as breeders, is progesterone.
The moment of ovulation is when the eggs are released from the ovaries, in dogs this does not mean the eggs are ready to be fertilized as they go through a further maturation phase making the ideal time for breeding 2-4 days post ovulation depending on the method of breeding (to be discuss in another post).
Now, how do we evaluate our females to determine when this ovulation happens? There are a few methods that I'll list below:
Behavioral and physical changes:
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Tail movement and positioning: often dogs will move their tail to the side, this is called flagging.
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Receptive to males: the majority of females become receptive to males during the fertile window although some can become aggressive as well.
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Appetite changes: many females lose their appetite during an estrus cycle, specifically during their fertile period.
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Roaming and wandering away: female dogs will often wander away in hopes to find an appropriate mate. It is best to keep your dog contained or on leash during any estrus cycle.
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Mounting: females that are entering their fertile window will often mount and hump other dogs.
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Playful: females tend to be more playful during this period than their usual selves.
Cytology:
We can perform vaginal cytologies to determine the mucosal changes happening within the female's body. I wrote about this in a previous post, HERE.
LH testing:
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We can test LH levels via blood or urine, blood being more accurate.
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Anytime we are testing LH levels we need to do frequent testing, ideally 2-3 times a day.
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Here at TBC we offer at home urine test strips which can be found HERE.
Progesterone testing:
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Progesterone testing is the most commonly used method and tends to be the most accurate. This is done with a blood draw usually starting on day 6-7 of mensus and done at frequent intervals thereafter until ovulation is confirmed.
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Each machine will have slightly different results so it is vital to know how your machine runs and to calibrate it properly.
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Here at TBC we offer a couple different machines for testing canine progesterone. Please reach out to us directly and we can discuss the options available and make recommendations to what may suit your breeding program the best.
Finecare Vet Progesterone Machine Bundle
VET CHROMA CANINE PROGESTERONE MACHINE BUNDLE
Ultrasound:
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In more recent medical studies, and commonly done in other species, we can perform an ultrasound to check for ovarian follicles. This is incredibly difficult to do in canines and is much less reliable than the other methods discussed above.
Here at TBC we are always happy to talk with you about your breeding program and your needs. Feel free to reach out to us directly to discuss your ovulation determining methods and how we can help assist you.
Written by Susan H, RVT