The document provides information about the heat cycle of female dogs in response to questions from multiple people. It describes the four stages of a dog's heat cycle - proestrus, estrus, diestrus, and anestrus. Proestrus involves swelling and bloody discharge as the body prepares. Estrus is the stage where the dog will accept breeding, lasting around 9 days on average. Afterward is diestrus, where discharge stops and lasts around 60 days. Finally anestrus is the resting phase between cycles, usually lasting 5 months. Signs a dog is in heat and when the cycle ends are explained in response to the questions.
Dog breeding is an Art. You may feel like you are gifted, but you need to work your craft. Canine genetics, inbreeding, heat, coitus, pregnancy, whelping and rearing of the litter. There's so much to learn!
Dog breeding is an Art. You may feel like you are gifted, but you need to work your craft. Canine genetics, inbreeding, heat, coitus, pregnancy, whelping and rearing of the litter. There's so much to learn!
ESTROUS CYCLE: Reproductive cycle of female, generally defined as period from one estrus to the next.
Two phases:
Follicular Phase
Luteal phase
TYPES OF ESTROUS CYCLE
1. Lh Surge And Ovulation Timing In Dogs
Understanding Luteinizing hormone
http://lhhormone.org
Maria asks…
What happen when a female dog is in heat?
What are the signs of dog in heat?
Can the dog breed when not in heat?
Are dogs in heat agressive?
How long does the heat last for?
Pregnancy Advisor’s answers:
Sexually mature female dogs will go through a heat cycle once, or more commonly, twice a
year. Each cycle consists of four stages:
1. Proestrus: Characterized by swelling of the vulva and release of a bloody vaginal discharge.
Sometimes the discharge is milky and other times dark red (or somewhere in between in
colour). Between bitches, there is a large variation in the length of proestrus, with an average
length of 9 days, and a range of 1 to 17 days. This is the “pre-heat” during which the male is
progressively more attracted to the female, but the female still rejects the male. This is a high
female hormone (estrogen) stage.
2. Estrus: This phase is often termed standing heat because it is during this stage that the
female will receive the male dog. Average length for estrus is 9 days, but again, between dogs
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2. there is large variation (range 3 to 21 days). At this point, the discharge may be absent, or
perhaps straw coloured. This stage is characterized by an increase in progesterone hormone
and an LH (luteinizing hormone) surge that leads to ovulation.
3. Diestrus: At this point, the female usually no longer stands for the male, especially further into
the diestrus stage. Vaginal discharge tapers off and the diestrus phase lasts an average of
about 60 days. Diestrus begins 6 days after ovulation. Progesterone hormones remain high
throughout this phase.
4. Anestrus: This is the resting phase between the active portions of the cycles. It normally lasts
about 5 months.
Hopefully that answers all of your questions. If not surely one of the sources that I listed below
can help you out.
Mandy asks…
is my golden retriever going into her heating cycle?
her nipples are pink, she barks a lot which is not normal , and she can’t hold her bladder which
never happens, but the only thing is, is that she’s not swollen and i dont see any blood unless
she’s cleaning herself. What other symptoms would let me know definetly she’s in heat?
she’s also getting out of her cage which that never happens
Pregnancy Advisor’s answers:
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3. Stages of the Canine Reproduction
In dogs, the reproductive cycle varies a lot. A bitch can begin her first estrous cycle (heat cycle)
at 6 months or as late as 2+ years. Generally though, puberty in canines begins at around 12
months, but in larger breeds it is usually at about 18 months to 2 years. A normal healthy bitch
will usually cycle on a regular basis, every 4 to 12 months. This is largely breed dependent, for
example the German Shepherd will cycle every 4 months. As they get older, bitches will cycle
less frequently.
There are four stages in the canine heat cycle (estrous) in dogs:
Proestrus: Getting Ready
Proestrus is the time when a bitch’s reproductive tract is preparing for the possibility of
breeding with a male dog. This lasts an average of about 10 days, but can be as little as 3 or as
long as 3 weeks. Its onset is usually accompanied by a bloody discharge from the vagina as
well as swelling of the vulva. A bitch that cleans herself can be hard to detect for a few days, so
it is a good practice to lift her tail and check every day. This seems strange, but will become
habit in time, and is the only way to be sure you have got the first day of her heat cycle.
Dogs will become attracted to a female during proestrus, but she’ll show little interest in the
male at this stage. The walls of the bitch’s reproductive tract thicken during proestrus and you
can use a cotton swab to collect epithelial cells (cells from the uppermost layer of the skin) from
the reproductive tract of the bitch, to view under a microscope. This is used to see how long she
is into the cycle.
The epithelial cells size and shape will change as the estrous cycle progresses. In the anestrus
stage of the canine heat cycle, the epithelial cells of the reproductive tract are small and round
with a dark spot in the middle (the nucleus). As proestrus ensues, these cells become larger,
more angular and have little staining of the nucleus and they increase in number. Under a
microscope, many red blood cells and some white blood cells, which were not present in the
previous stage, can be seen in proestrus.
Hormone levels also change during proestrus. Although estrogen levels rise in anestrus, they
stay relatively low during the early part of proestrus. As the bitch enters the later stages of
proestrus, however, estrogen levels continue to rise, reaching their peak near the end of this
stage. Estrogen begins to fall as progesterone levels begin to rise. Progesterone remains high
throughout the next two stages of the heat cycle, and is the hormone routinely used to test for
when a bitch is about to ovulate and, therefore, should be bred.
Estrus: She’s Ready
Estrus is the second stage of the estrous cycle. It also lasts an average of 9 to 11 days, but can
vary from 3days to 3 weeks. This is the time when the bitch accepts the male dog for breeding.
During this stage, she sometimes exhibits a behavior called “flagging.” This involves the bitch
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4. standing in one place, maybe shuffling her feet, while at the same time, lifting her tail to allow
the male to sniff her hind end.
During estrus, the vaginal discharge decreases, becoming less bloody in many dogs. The
discharge will become a straw olor. None of the small round epithelial cells that were typical of
early proestrus can be seen under a microscope in estrus. Rather, a lot of angular platelets can
be seen, stacked on top of each other.
The progesterone level continues to rise. Near the onset of estrus, there is a very short rise in
another sex hormone, luteinizing hormone (LH). Once this has peaked, ovulation usually occurs
within 24 to 48 hours. The prime time to breed the dog is approximately 2 days after ovulation or
4 days after the LH surge.
Diestrus: Progesterone Dominates
The next stage of the heat cycle, diestrus, is considered the period when progesterone
dominates the hormone scene. Diestrus lasts from 60 to 90 days in a dog that doesn’t become
pregnant or approximately 63 days in a dog that does become pregnant.
In diestrus, the vaginal discharge will stop and the epithelial cells of the reproductive tract
quickly appear small and round again. White blood cells can be seen in very high numbers
during the first few days of diestrus. This is normal, since their function is to clean up the cellular
debris left behind by estrus.
Anestrus: The Final Stage
The final stage of the heat cycle is called anestrus. Anestrus lasts an average of 4 to 5 months.
During this time the sex hormones are at very low levels, although they do continue to have
small rises and declines throughout this stage. If a swab of the reproductive lining is taken and
viewed under a microscope at this stage, very few epithelial cells can be seen.
Also check out:
http://www.vetmed.lsu.edu/eiltslotus/Theriogenology-5361/the_normal_canine.htm
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5. Sandra asks…
when is a dogs heat over!?
my female and male dog are seperated right now cause my female went into heat. My male is
going CRAZY! he constantly whines when in or out of the house! its driving me nutz! he was
fine last week but this week he is out of control going crazy!
I know what everyone is going to say… to get her fixed. I havent because I am looking into
finding a new home for her because my relationship is failing and I dont have any options and
just cant care for her right now. With work and trying to find an apartment- she is a big dog and
needs a backyard. So I didnt get her fixed in case the next owner doesnt want her fixed.
Pregnancy Advisor’s answers:
Sexually mature female dogs will go through a heat cycle once, or more commonly, twice a
year. Each cycle consists of four stages:
1. Proestrus: Characterized by swelling of the vulva and release of a bloody vaginal discharge.
Sometimes the discharge is milky and other times dark red (or somewhere in between in
colour). Between bitches, there is a large variation in the length of proestrus, with an average
length of 9 days, and a range of 1 to 17 days. This is the “pre-heat” during which the male is
progressively more attracted to the female, but the female still rejects the male. This is a high
female hormone (estrogen) stage.
2. Estrus: This phase is often termed standing heat because it is during this stage that the
female will receive the male dog. Average length for estrus is 9 days, but again, between dogs
there is large variation (range 3 to 21 days). At this point, the discharge may be absent, or
perhaps straw coloured. This stage is characterized by an increase in progesterone hormone
and an LH (luteinizing hormone) surge that leads to ovulation.
3. Diestrus: At this point, the female usually no longer stands for the male, especially further into
the diestrus stage. Vaginal discharge tapers off and the diestrus phase lasts an average of
about 60 days. Diestrus begins 6 days after ovulation. Progesterone hormones remain high
throughout this phase.
4. Anestrus: This is the resting phase between the active portions of the cycles. It normally lasts
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6. about 5 months.
Hopefully that answers all of your questions. If not surely one of the sources that I listed below
can help you out.
Lisa asks…
Dog Estrus Cycle & LH peak?
I do not monitor for LH Surge, I have a girl who has been in Standing Heat for 11 days, and
may continue. How can I accurately determine a due date? I have been keeping track of her
mood and other differences over the last week, are there any behavioral changes when the LH
level goes up?
Pregnancy Advisor’s answers:
As far as I’m aware, the only reliable point you can time from is the LH Surge (which coincides
with ovulation). Behavioral markers won’t necessarily be accurate.
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7. Carol asks…
Why is there some blood in my CM? Ovulation spotting?
Well, my period started on the 31st of last month, and then seemed to stop completely on the
2nd (but got a little heavy again and had some spotting on the 3rd and 4th). My boyfriend and I
had sex (with a condom, mind you, so this isn’t an am-I-pregnant question) on the 2nd and 3rd.
After that, I dried all up down there, which is normal. Well, I’ve started watching what I eat and
exercising a little, and today I ran with my dog (but nothing out of the ordinary). Just about 10
minutes ago, I had more diarrhea (sorry TMI) and I think that’s from changing my diet, but
when I happened to glance down, there was a long, stretchy strand of pinkish CM hanging from
my vaginal opening, and it was VERY stretchy. When I wiped, there was a little bit of red blood
mixed in with the CM. This has never happened before. Do you think it’s from exercising? Or
could this be ovulation spotting? My bf and I haven’t had sex since the 4th, so it can’t be from
that. Should I be worried?
Pregnancy Advisor’s answers:
There are a couple of thoughts on what causes ovulation spotting. Some people believe that the
light spotting is a result of the egg rupturing through the follicle during ovulation. It is thought
that as the egg bursts from the follicle that a little bleeding may occur. This is why some women
may notice brown/pink spotting, which is generally an indicator of older blood, around the time
they ovulate. The blood may turn brown as it exits the body.
The other possible explanation for ovulation spotting is that the spotting is a result of a
woman’s changing hormones during ovulation. As a woman’s body prepares to ovulate,
follicles will start to grow and mature. As they mature they produce more estrogen. This
increase in estrogen triggers a surge in LH, another hormone involved in ovulation. When LH
surges it signals the mature egg to burst from the follicle. Estrogen rises sharply right before a
woman ovulates and it is thought that the increase in estrogen levels may cause light spotting to
occur.
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8. I experienced this once or twice in the past and asked my doctor about it as I was concerned,
he said not to worry as it happens to some women and it is quite rare for it to happen, but it just
means that you are really fertile at that moment and if wanting to conceive that would be the
perfect time. If not wanting to conceive, he said to use protection such as condoms. I would
recommend that if you have any concerns that you consult with your doctor for further
evaluation and peace of mind should you wish.
Good luck
Linda asks…
Does this mean I am pregnant?
I am currently TTC. I took a Clearblue digital ovulation predictor test, and it came up as “not
ovulating”. My BBT temp was 98.6 degrees, but this is also my first day taking the temp.
When I take the insert out of the tester, there is a little window, that before I peed was all white
and clear, and now there is a solid blue line, and a faint blue line to the left. Basically, to me it
looks like a pregnancy test (faint line would be the line indicating pregnancy) but I don’t know.
Nowhere in the booklet does it discuss a pregnancy test, and when I called the number it is
nothing but automated questions..
Sooooo does this mean I may be pregnant? I have an e.p.t test here, but the directions say to
use on the first day of your missed period, and that shouldn’t be till a couple weeks from now?
Background info: I have PCOS, I only get periods when I’m on birth control
There are two parts to this tester. One that you pee on, then insert. That has the little window
with the one line and one faint line. Then there is the thing i inserted it into which tells me
digitally if I am ovulating or not.
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9. Pregnancy Advisor’s answers:
1) If you’re not having periods, there’s no reason to expect that you’re ovulating at all.
Ovulation itself is what causes the period to come (about two weeks after ovulation) in a normal
cycle. There are other reasons that a woman might bleed even if she isn’t ovulating. So just
having a period isn’t a guarantee that you ARE ovulating. But not having a period is pretty firm
sign that you’re NOT ovulating.
2) As you’ve already been told, ovulation testers and pregnancy testers work differently. A
pregnancy test is just looking for a hormone called HcG for short. If you have even a little HcG
that causes a second line on the test, you’re pregnant, because HcG in any amount is rarely
around except if you’re pregnant. You know that.
But you bought an ovulation test kit. That’s why it doesn’t say anything about pregnancy
testing in the kit. It’s not meant for that. Your confusion is due to lack of experience. It is similar
to a pregnancy test only in the same sense that a cat is similar to a dog. Yes, they’re a little
alike in basics, but ultimately, they’re two different beasties.
Ovulation tests are measuring a hormone called LH for short. LH is ALWAYS present in your
body, even if only a very little bit. So the tests will always have a second line, however faint,
because there is ALWAYS LH in your body. It takes a certain high amount of LH for ovulation to
happen, though, called an “LH surge.” So an ovulation test is only considered positive if the
second line is equally dark or darker than the control line. That indicates that there are
unusually high levels of LH.
3) LH presence doesn’t officially mean you’re ovulating. At least, not yet. Ovulation usually
follows about 12-36 hours AFTER the LH surge. The hormone needs some time to work. But it
does mean that you should make sure to have intercourse then if you’re TTC. In some cases,
though, you should be aware that LH surges may fail and result in no ovulation at all. Ovulation
test kits have no way to confirm whether ovulation truly does happen after it detects the LH
surge.
4) Any kind of tester–ovulation or pregnancy– that is digital is meant for you to rely solely upon
the digital part anyway. Don’t look at anything else.
5) Wasting money on all those testing kits when you’re not even ovulating is a bizarre
investment, really. No ovulation = no periods = no possibility of pregnancy. While you could
theoretically start ovulating again at any time (which is why someone not wanting kids should
still use protection), you cannot bank on it EVER happening on its own until the cause is
identified. If you are extremely over or under weight, or if you are on an intense athletic training
regimen, or have PCOS complications that need to be brought under control, or whatever, those
issues will have to be addressed or you will never ovulate anyway. Getting testing kits to see
when you ovulate when you already know you don’t ovulate is just a waste, though.
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10. Powered by Yahoo! Answers
Answering Your Questions on LH Surge
http://LHSurge.org
Lh Surge And Ovulation Timing In Dogs
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