OVULATION ALWAYS OCCURS BETWEEN 5 and 10ng/ml PROGESTERONE – NOT SIMPLY AT 5.0  

Years ago before we had progesterone testing, we used to use ‘a rule of thumb’ that suggested breeding on cycle days 12 and 14 with Cycle Day 1 being the first day of red blood. “The most common problem I see breeders deal with in reproduction is the timing in getting a bitch pregnant”, says Fran Smith, D.V.M., Ph.D., a board-certified small animal reproduction specialist in Burnsville , Minn.   In fact, even when the dog and bitch are healthy and you breed at the right time, 15% OF THE TIME, THE MATING STILL WON’T RESULT IN A LITTER”.

One of THE ‘gurus’ of canine reproduction in North America is Robert Hutchison,  North Ridgeville , Ohio , agrees . “Poor timing is still one of the main causes of a missed breeding."..." There is a lot of individual variation…. There is no magic day; I’ve seen a bitch ovulate on day 8 and another one ovulate on day 32.” Dr.Hutchison holds infertility seminars throughout the year as well as writes many articles available to breeders on-line.

In dogs, progesterone is a reproductive hormone that begins to increase in the bloodstream as ovulation approaches. When the level is approximately 2.0 + ng/ml, the hormone (LH) or luteinizing hormone is sent out from the pituitary gland at the base of the brain. The ‘surge’ of LH signals the beginning of the eggs being released from fluid filled sacks on the ovary containing the immature eggs and when the progesterone level is between 5 and 10 ng/ml, the bitch is ACTUALLY RELEASING eggs perhaps two, then one and NOT all at the same time. Dogs are the only mammal that ovulate IMMATURE EGGS; it takes two to three days for them to be ready to fertilize. After the eggs are released, THEY CONTINUE TO MATURE for at least 48 hours to 3 days.

(When I worked in In Vitro Fertilization, we would use medication to mature a group of about 50 eggs and when a certain number were in the mature state, we retrieved them to the lab; many were ‘tight’ or immature and could not fertilize and others were ‘post-mature’ and also would not fertilize).

Bitches DO NOT all ovulate at 5.0 ng/ml and breeding plans should NOT be based upon them reaching 5 !  Some will sit at 5 or 6 for days before actual ovulation.  

BITCHES ARE BEST BRED WHEN THEIR PROGESTERONE LEVEL IS

9.5 ng/ml – 10 ng/ml. No more than 3 tests should be needed for a normally cycling bitch

Most veterinarians are using a QUANTITATIVE test using clear plasma for a measured level. This gives the ‘number’ that comes back from the lab. However, some veterinary laboratories as well as many breeders are using  ‘in house’ progesterone kits (Blood sample not sent to a certified lab but drawn and placed into the kit on hand), and these kits give a reference RANGE as their result ; ‘Below baseline’ or over 7 ng. Some of these $100 in-house kits give results in a color range that again is NOT specific. Test kits must be at room temperature and have a definite shelf life that must be carefully monitored. As well, the timed reading of the results is important; if they are to be read at five minutes, results read later than that would be suspicious.  I have been personally frustrated trying to send good semen to someone using an in-house test giving colors that are compared to a chart and not having a quantitative number measuring the progesterone level. Some breeders draw blood and do progesterone test kits on their girls EVERYDAY for five days and still missed the breeding. ONLY ENZYME IMMUNE ASSAY tests using a blood sample processed for a plasma sample give a specific progesterone result to the 100^th percent, as a number and RELIABLE..

It IS possible for a bitch to go to 5.0 ng/ml and STALL; they are often bred soon after hitting the magic number of 5 and then not conceive. Those bitches will take longer than is normal to RISE to 9+ ng/ml, and their timing for breeding is TOO EARLY. ANOTHER TEST SHOULD BE DONE AFTER THEY ARE 5.0+ AND TO THEN SEE A RISE OF AT LEAST 4 points TO ENSURE THAT A STALL DIDN’T OCCUR.  Bitches progesterone levels SPIKE INTO THE HIGH TEENS THE DAY AFTER OVULATION.   

* Quantitative Progesterone test to 5.0 ng/ml and then 2-3 days later looking for

9+ ng/ml – CONSIDER THIS OVULATION

* Inseminate 48 hours later and a second A.I. ONE to TWO days later

* THE 3^rd DAY AFTER OVULATION is considered CONCEPTION (when MOST of the eggs will fertilize); 60 days from this is the due date.  (Conception + 3 days prior being OVULATION = 63 day formula)

STUD DOGS >   should not be collected MORE OFTEN THAN EVERY-OTHER-DAY on a REGULAR basis.  IF he has more than one bitch come up for breeding in a week and being within a day of each other at peak fertility based upon progesterone testing, I believe the ejaculate should be split with a good but minimum dose provided to each bitch.  Utilizing Tran cervical and surgical inseminations does reduce the breeding dose of semen required (Much of the semen deposited into the vagina in a fresh AI or natural breeding is lost because of vaginal environment). IF the dog is not given a day in between collections, semen quality will suffer.

The best semen collection is achieved by using a teaser bitch to either mount or smell to excite him as the ejaculate is collected. Semen is ejaculated in 3 ‘fractions’ or thirds. 1) Pre-Sperm from the prostate and urethral glands and might possibly cleanse the urethra of bacteria and urine  2) Sperm Rich comes from the stores in the epididymal and vas deferens stores of semen made days and weeks earlier. 3) Fluid from the Prostate Gland – provides volume to the semen does help the sperm toward and through the cervix and into the uterus and give the sperm nutrients. When semen is collected to ADD EXTENDERS AND CHILL FOR SHIPMENT via Fed Ex or UPS, the 3^rd fraction which is the clear (that collects onto of the white sperm-rich fraction), should be gently pulled off before extender is added.

I keep my collection sleeve and attached collection tube, the pipette and the syringe in my clothes close to my body to become body temperature as cold and also extreme heat will kill sperm. Breeders have sent questions about not being able to pull the skin sheath over the bulbus before it begins to swell and asking, “Can I collect a good sample with the bulbus inside the skin sheath?”  Your dog may not want to be collected again; that’s NOT comfortable and, you will not likely get a full or complete collection. When I start the process of being on my knees and put my fingers of my right hand just behind the tiny but developing bulbus, I keep my fingers in place to stop the dog from pulling back in and ending the process and the increasing pressure there causes the beginning of ejaculation and the bulb continues to increase in size. IF you can’t use your left hand somewhat quickly to push the sheath skin back over the bulbus when it is small enough to do so, stop and send the dog away to another room or just outside and wait a bit until he relaxes back to normal size. I have sent boys away two or three times until they are ‘recovered’ back to normal and start again. As the skin is slipped over the small bulbus, use either hand’s forefinger to tighten around and above the developing bulbus and slip the artificial vaginal up over the penis. Continue to hold pressure, switch hands if needed and you’ll feel the pulsating in your hold as the ejaculate comes into the connected tube.

Either before or after the insemination, I pull off a few drops of the sperm rich fraction and  a drop on a warmed slide and cover with a warm cover slip to evaluate sperm count, percentage that are moving (motility), how fast the sperm move forward progression and look for poor tails and percentage that are dead. A normal ejaculate has about 70% motile/moving sperm or better. .

  Attach the pipette securely to the syringe and place the tip of the pipette at the bottom of the collection tube. SLOWLY draw up the semen (too fast will destroy the tails needed to move through the cervix, the uterus and ultimately, into the eggs. With lubricant, slide the third finger of your not-dominate had into the bitch’s vagina and through any tissue lumps, strictures and up and over anatomy as far as you can get. Gently slide the pipette along the palm side of the hand and third finger(Knowing WHERE you are inside her), and when the  pipette ‘stops’, dispense a little fluid from the syringe for lubrication and gently rotate the pipette as you try to slide it still forward. Take some time to play with this and you’ll find that most of the time, if the bitch is soft inside and ready to breed, you will pass the pipette quite far forward and right TO the cervix.

   Dispense the semen SLOWLY, remove the pipette and leave your third finger in place to block any fluid loss. You can put her rump up over your knee and ‘feather’ her vulva which causes her vagina to clamp down on your finger and pull the fluid toward the cervix. Within 10-15 minutes, the sperm IS AT THE EGGS being assisted by a chemical given off by the mature eggs to attract the sperm.

Having had a specialty winning champion stud dog become sterile years ago through natural breedings, I know that it is much easier to treat a female reproductive system than the tightly wound testes in the male. With a very high percentage of semen killed by the environment of the vagina, I only perform breedings by Artificial Insemination now, always providing more good sperm through the cervix and to the eggs not only for larger litters but also protecting stud dogs who have so much to potentially lose. 

REFERENCES  

*Reproductive Revolutions; Cheryl Lopate, MS, DVM, Diplomat American College of Theriogenologists , Aurora , OR

*Canine Cryo Bank;  Sue Wells Laboratory manager, San Marcos ,  California

*Today’s Breeder’s Article; Frances Smith, DVM, Ph.D., board certified small animal reproduction specialist, October 2004

*Today’s Breeder Article; Robert Hutchison, DVM, who specializes in canine reproduction, October 2004.