Progesterone levels

English bulldog breeding and optimal timing with progesterone levels


  • Improper timing of breeding English bulldogs is often the cause of unsuccessful breeding, so progesterone test is always a good way to go specially if you have problem bitches or ones that will not accept the male.


  • The conception rate after a single breeding is highest if the bitch is bred 3-10 days prior to Day 1 of Diestrus (D1).


  • After a single breeding, the number of live English bulldog pups per CL is highest when the breeding occurs 4 days prior to D1 by a proven, fertile English bulldog male. This would equate to the fifth day of estrus for an average, normal 9 day estrus.




Fertile English bulldog male


The breeding English bulldog male should be free of canine Brucellocis.

The ejaculate should contain at least 200 x 106 total cells after centrifuging is done.


It should have 80 % motility


80% of the the cells should have normal morphology.


Breeding English bulldogs

If natural breeding on your English bulldog is performed, be active in the breeding process of your bulldogs. Observe the breeding to see if a tie occurred.


Do not just leave the English bulldog together and hope they breed, they can become agitated and suffer from a stroke always breed in a cool place with AC.

The timing of the breeding of an English bulldog is important. If the male and female are both available for unlimited breeding, then breeding’s can be done every other day the bitch is in estrus


Optimal Progesterone level and and timing for optimal breeding English Bulldogs


The estrous cycle should be monitored to establish when the bitch is actually in estrus.

This is important because there are several reasons why breeding may not occur, or the fertile period may be missed.

Some reasons include: male – female incompatibility caused by physical problems in either the male or female.


Psychological problems.

Behavioral problems.


If there are constraints on the availability of the English bulldog male, or the number of breeding’s possible, it is important that the cycle be monitored carefully to ensure the optimal time to breed.

Management of breeding’s using shipped, chilled semen or frozen semen require excellent timing of the fertile period.


Methods for timing a breeding include:

Behavior of the English bulldog bitch, such as flagging the tail and standing to be mounted.

Physical signs such as:

Vulva swelling

Bloody discharge.


Vaginal cytology

Ultrasound examination of ovarian follicular activity

Hormone assay for either progesterone or LH.


While vaginal cytology is fairly reliable, all other methods are unreliable except for hormone assay.


Hormone assays are the best way to determine the fertile period.





Relative progesterone concentrations during the proestrual/estrual period.


P4 (ng/ml)


Relative time points


1.1-1.9 Before LH surge


2.1-2.9 Day of LH surge


3.1-3.9 Days 1-2 after the LH surge


4.0-8.0 Day of ovulation


10-80 2-3 weeks post-ovulation


Progesterone Testing

The initial progesterone rise during estrus in the bitch coincides with the LH peak.


Before the LH peak the progesterone is < 1.0 ng/ml.

On the day of the LH peak, progesterone rises to around 1.5 – 2.0 ng/ml. Thereafter the progesterone is > 5 ng/ml.

Using my lab equipment ovulation occurs at about 3.8-5.0 ng/ml (11.7 nmol/L) of progesterone (including the day of ovulation and the 24 hours it takes to ovulate) and the best days to breed English bulldogs is when they are about 17.6-24.1 ng/ml (54-74 nmol/L) of progesterone.


Progesterone levels and calculating more or less the day to start breeding your English bulldog

First of all the blood should be taken from the jugular vein, more of less 6 ML and put in a red cap blood container.

The normal early readings are: .1 – .2 .3

Start to draw blood from your English bulldog bitch on the 7th day.

They can go back down to .2 or even .1 – this depends on the time of day the blood was drawn.

When the LH surge goes over 1.0 to 1.9 – you can breed your English bulldog in 5 to 6 days.

If the 5th day seems a little early – you would want to breed your English bulldog on the 6th and 7th day – then skip a day and breed again.

If you draw blood and the level is .2 or .3 – then wait 3 days and draw blood again.

If you draw blood and the level is .7 or .8 – then you do it every other day

Once you start to see the level at:

2.0 to 2.9 ng/ml = breed in 4 to 5 days

3.0 to 3.9 ng/ml = breed in 3 to 4 days

4.0 to 8 .0 ng/ml = breed today or tomorrow – this is where the LH Surge Occurs.

Over 8.0 ng/ml with no white sells – then the bitch has ovulated

When you hit the level above 4.0 ng/mL this is day 1 of ovulation. Then it takes approximately 48 hours for the ova’s to mature enough to be fertilized…..then they can be fertilized for approximately another 48 hours.

When you breed – you breed 2 days in a row – then skip a day and breed another time.

When you have an English bulldog bitch that do not swell up or has a lot of discharge – then check their thyroid level, and they may have to go on thyroid pills for the rest of her life Levothyroxine“ is the pill you would need to use.

So in my opinion and Conclusion on progesterone levels after many years of breeding here is what I do and I have a 95% conception rate.

If your bitch is at a level of progesterone of 5ng/ml and you have good semen from a good stud you can start to breed her and semen should stay alive inside her for at least 5 to 7 days.

If your have semen that was shipped to you and it’s chilled you can start to breed when the progesterone level is at 8.0ng /ML to 12.0 ng/ ML semen should live at least 2 to 4 days inside her.

If you have frozen semen or from an older stud that the motility and quality is no good than you breed when the progesterone level hits at 17 ng/ml to 24ng ml that is when the eggs are fertile and semen will immediately enter the egg.

Thank you guys for visiting my web site and I wish you the best of luck on your English bulldog breeding and getting the correct progesterone levels on your bitch, if you have any questions please don’t hesitate to contact me and remember

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