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Northwest Notes / THE LABRADOR QUARTERLY Summer 2009

Diann Sullivan

In my area, we are blessed to have a reproductive veterinary specialist about an hour's drive North in British Columbia; otherwise, it's really over two hours South to Seattle. This clinic has eight veterinarians and is open seven days a week. I originally went up there for pregnancy confirmation ultrasounds at 28-31 days and have also done semen surgical implants and one c-section there. Whenever I'm there waiting, I see many top breeders of multiple breeds from that Provence, Alberta and Washington come in for breeding help and sometimes I am just amazed at how much they could do themselves if they had the chance to learn simple procedures and more about breeding cycles also. The last time I was there, two different breeders came in for 'emergency appointments' because they had tried for days to breed their bitches and “the stud wouldn't just do it and they needed an artificial insemination” desperately.

Did they try for too many days and now the A.I., though possible to physically do, may be too late if the eggs are died off now....... The charge is reasonable there for the A.I. procedure; to collect the stud dog, pass the pipette to the cervix and release the sperm for $85. But I believe that every stud dog owner should learn how to time cycles for conception and learn how to do this simple procedure themselves without having to run into the vet with both dogs in panic. I like to see stud dog owners do everything they can to spare the bitch owner the sadness and loss of a missed breeding.

Dogs are structurally different from humans and hormonally different as well. Hormones control their how often they ovulate and come into season, the number of eggs a female will produce and their desire to breed. They breed to reproduce themselves and not for any other reason and therefore the hormones are specific to the females desire to 'stand', 'flagg' and accept the male's mounting and allowing penetration.

Female dogs are born, like girls, with thousands-and-thousands of FOLLICLES (picture grains of mustard seed by the thousands in each ovary). After the shedding of the old bloody lining of the uterus, the pituitary gland begins to send FOLLICLE STIMULATING HORMONE (FSH) to the ovaries; * the amount and time frame in which FSH is sent is somewhat individual among females. (remember this). The FSH is sent in an AMOUNT that will stimulate a certain number of the 'mustard seed sized follicles' to develop into mature eggs, to be released for fertilization. When a breeding is done in good timing so that sperm is present WHEN the eggs are not only released but also mature, only the number of eggs can be fertilized that were released from the ovaries... If there was just enough hormone to mature five eggs, with good sperm timing there should then be five puppies. IF she released nine mature eggs but sperm was present only later in her cycle, some of the eggs may have already died off, and there would be a lesser number of puppies conceived than the original nine eggs ovulated. .

As the eggs begin growing in response the the FSH, the maturing eggs produce estrogen into the blood stream and this wonderful hormone causes the uterus to make a new bloody lining for puppies to embed in and develop. The developing eggs also produce an increasing amount of progesterone as the eggs mature toward ovulation readiness. 'In the old days', breeders goaled to breed on cycle days 12 and 14 based upon the average bitch ovulating at cycle day 10 (cycle day 1 is the first day of blood), and knowing that the eggs in the dog had to mature for at least 48 hours before they could fertilize. NOT all bitches have the same amount or FSH hormone released or over the same time period though and that is why we should not breed by cycle days alone.

The behavior of the average bitch changes at approximately ovulation and from the hormone progesterone being released into her blood stream. Progesterone's main purpose is to actually hold the bloody lining 'on' and in place, stopping the loss the lining before embryos are implanted and can sustain themselves. The developing embryos then produce even more progesterone to support the developing uterine lining and keep it there. Some bitches behavior includes swinging their tails to the side to allow the dog's penis the ability to find the vulva (flagging), very early after coming into heat and others are more frigid and don't show behaviors of breeding readiness until days later or, hardly at all. Usually, a bitch in season and close to ovulation will mount other bitches and be very flirty with males. She will often twirl around throwing her rear end into the dog's face and flag her tail to the side. But just that behavior alone cannot accurately predict the bitch's fertile period, nor can counting cycle days.

Her behavior may or not coincide with her readiness to get pregnant. I remember back to a female I had sold to a gun dog trainer several states away and many years ago who came into season just after the arrangements were made. It was agreed to wait and not ship her until she was 23 days past her first day of bleeding when she should have been long past a time of being breedable. She was bathed to remove any lingering scent and shipped and yet once in her new home, almost four weeks from cycle day one, she invited a young male with flagging behavior, let him mount and they tied ! I prompting received a stern phone call because I had assured them she was past estrus. She did not become pregnant.

We have today a wonderful and predictable way to know where the female is in her estrus cycle, the blood (serum) progesterone test. I have seen this done improperly a couple of times when ordered by veterinarians who really know nothing about reproduction as a qualitative test resulting in either POSITIVE OR NEGATIVE, instead as qualitative, resulting in a number. It is drawn by any hospital or clinic and the blood is sent to a lab and in most cases, the lab faxes the result to the ordering vet the next morning. It should always be ordered as quantative and that would be a good question to ask when drawing for the test. If it is drawn before 11 AM, results are ready that same evening. I early on had the vet drawing for me say that he didn't know that much about it and I should call and get my own results to use for planning my breedings.

Dogs will ovulate between 3.5ng/ml and under 10.0ng/ml as extremes and * 5.0 is considered by veterinary fertility specialists as the value to be considered for ovulation. IF you are ahead, you can't go wrong since the eggs need to mature at least 48 hours before they can be fertilized. Yet in my area, the cost for drawing this test and sending the blood sample to the same lab costs anywhere between $47 and $96 per test. I know that bitch owners are often not 'right on' about the first day they see blood (cycle day 1), so I suggest a progesterone test first done at cycle day 8. Most females will have a result of about 3.5 and most will 'change over' one whole number a day after reaching a minimum level of 2.0- I can easily breed them during their fertile period testing once if they are within that normal result. A beautiful yellow girl from outstanding lines who is pregnant and due may 4 tested 2.1ng/ml on day 8 and I just counted her forward to 5 as we had cycle data on her from prior breedings. The bitch should be inseminated or bred approximately two days after she would have been considered to have ovulated. She should become pregnant if she receives semen within the next three to four days.

I worked with a two-and-a-half year old female whose owner drove her down seven hours from North British Columbia near the border of Alaska when she was on cycle day 4. The owner was in college full time and the drive down and back required her to use a weekend. Once before, I had sent semen up to her for insemination for breeding her other older female with horrible result (the Canadian border pulled the box aside for inspection (clearly marked 'Perishable' and shipped second day air), and it sat in a room for 4 days and was ruined after a cost of $164 to ship it. This time, she was determined to bring the bitch here. I made sure that the owner did not count cycle day 1 BEFORE she saw red blood on the floo, telling her I wanted the bitch to truly be in season before she moved her all that way. Her cycle day 8 progesterone was 0.7ng/ml ! Three days later, she was 1.7 and day 14 was 2.9ng/ml ! (The owner did not want o pay for any further progesterone testing though I used a vet who charged $47 each test.) SHE flagged from cycle day 11 and she mounted the stud dog yet I knew she was only 1.7 progesterone. She showed the outward physical signs of being 'ready' as well with her vulva the turgidity similar to my bottom lip.

The stud dog is very experienced and 'the type' that will not mount and will barely let me collect him unless the female has mature eggs...... I gave him a short time each day from her day 14 to watch his behavior. With his last four bitches, he also didn't mount until they were a couple of days past ovulation; they were successfully bred and each of them had full litters. I was able to collect small amounts from him and inseminated cycle day 16 to do my best to cover her. My method for inseminating includes sliding the pipette over my left third finger guiding it's tip to the cervix. Though she wasn't tight inside as a bitch would usually be before her eggs were mature, she did not grasp my finger (clamping down rhythmically), during the process. Females during their most fertile days do this 'grasping' with their vagina,drawing the semen forward to the cervix and as part of the 'tie' in natural breedings. Could this bitch not be ovulating this cycle?

In fertility nursing with the IVF practice I was with for years, we performed a trans vaginal ultrasound every couple of days or every day depending on how fast the follicle was growing to the size that we knew contained a mature egg. In women, approximately 50 follicles come to the surface of the ovary every month and enough FSH is sent to bring one egg (most often), to maturity. Most women had the mature egg at day 12 and yet, some were very upset that they were coming back multiple times at $$ each visit because their follicle was very slow to grow. Most did eventually reach mature egg status on their own, and yet, some do not without medication. But in animals, it is extremely rare for them not to come to ovulation.

On cycle day 20, for this female here from Northern Canada, this stud dog went nuts. He mounted vigorously and tied for a natural breeding. I let him skip 36 hours and had another successful tie. She was positive for pregnancy at 30 days on ultrasound. In her case, she must have had a slower release of follicle stimulating hormone that matured her very slowly yet they did reach readiness for ovulation; It took her a much longer time but she did get there.

Once the eggs ovulate and mature for two days, they become able to accept sperm and fertilize. The eggs will then be mature and capable of fertilizing for two to three days before dying off. Sperm of good quality inside the female will live up to six days and I have influenced the number of females in a litter by inseminating at or just before ovulation. The male sperm swim faster and reach the eggs first, but don't live as long as the female sperm who swim slower. In the case of the Canadian female who was inseminated four days before her prime fertile period, she should have had a majority of female sperm sitting there waiting when the eggs did mature and, should have a higher percentage of females conceived. The litter I have now, was bred by insemination when she was progesterone tested to be at 3.8ng/ml on cycle day 8;she did not grasp my third finger vaginally. I like to do an early collection and insemination for each female to have a semen sample to check under the microscope also for count and motility, helping me to keep a record for my stud dog and, to be able to tell my bitch owners that their girls were bred with excellent sperm. My girl was in 'the norm' and she progressed to a CD 10 being 5.4ng/ml ovulated. With her peak fertility CD12, she was inseminated a second time and was different from the first in that he was very assertive in mounting her vigorously and, when doing the insemination, she grasped my third finger vaginally and clamped down hard leaving it red/purple after the 10 minutes I leave it in place. I either 'feather' her vulva and/or let my stud dog lick her for those 10 minutes, causing the vagina to squeeze rhythmically . She whelped exactly sixty-three days from ovulation and had six females and two males.

Younger and more inexperienced stud dogs or those who are just 'driven' sexually, may mount at anytime and try breeding the female, even if the timing for pregnancy isn't even close. For the dog, it's not necessarily about libido or willingness to mate; it's about us gaining the knowledge to develop a plan. The stud dog's nose often gives him information that we just couldn't know without progesterone testing.

When I prepare a boy puppy for keeping him as a future stud dog, I begin early. From when he is very young, I will gently stroke the end of the penis/sheath until I feel him getting erect or he seems excited. . I always praise and pet him and encourage his letting me handle him. I also give him chances to explore bitches in season and praise him when he is interested. As he get older and shows interest in females, even mounting, I will praise him and build him up though I may have to rescue the other dogs he is mounting.

We are so fortunate to now have “better science” helping us to know when the bitch's time is to ovulate and allow us to make breeding plans that will be accurate. We no longer only rely on cycle days or the behavior of the dogs. Breeding failures today are more related to adhering to old breeding practices rather than a problem with the bitch. We certainly cannot control everything perfectly with just using ovulation timing tests as bitches can even ovulate and be bred in good timing but lack a healthy uterine lining one cycle and not produce puppies. The phenomenon of absorbing puppies after conception occurs also but that is something we rarely realize with the very early pregnancy testing unreliable in dogs. In infertility nursing, we could watch this occur on trans-vaginal ultrasound and many times, saw a seven week old+ pregnancy with a beating heart, gradually diminish in size as it was reabsorbed. The cause is usually a missed cell division because of a 'problem' in that conception and when growth stops, the mother's body begins absorbing the uterine contents.

A successful breeding program must incorporate all of the new advantages science provides us. There are other ways to test for ovulation but the blood (serum) progesterone is the most accurate and knowing when ovulation occurs does give the stud dog owner the ability to develop a breeding plan. He can discuss with the owner of the bitch coming to his stud dog when he wants her if she is actually coming for a natural breeding with fresh semen and, ovulation timing is critical for the plan needed to collect, extend and ship overnight for fresh-chilled breedings. We can also learn to trust our experienced stud dogs, as I am still, in some unusual cycles that do occur also.

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