Spayed female dog still having “heat cycles”?!

That could be a tabloid headline, though I guess it's pretty tame compared to "Elvis sighted in laundromat!" or "Politician actually admits lying!".  The point is that it's weird — dogs who have been spayed have no uterus and no ovaries, so how could they still be having estrus cycles and coming "in heat"?

Once upon a time, about 28 years ago, I spayed a Scottish Terrier.  She continued to have heat cycles, and I was mystified (not to mention mortified).  That is NOT supposed to happen.

Now, I have to tell you: when you're performing an ovario-hysterectomy on a dog, sometimes it's pretty hard to pull the ovaries up out of the abdominal cavity.  If you're not careful, you might cut things a little close and leave some ovary in there.  When you've cut things off, you need to inspect what you removed and be sure the whole ovary is there (plus a little extra tissue, just to make you feel good about getting  100%). 

If you leave some ovary in the dog, they will continue to cycle regularly, coming in heat every six months. They won't get pregnant, since you've removed the uterus, but they still come in heat, they are still at greater risk for breast cancer, and could even have "female trouble" developing pyometra in the stump of the uterus.

Sometimes, you cut things pretty close, but in the case of the above Scottish Terrier, I recalled vividly that there had been no problems at all.  It was not a "close call".  So, I called the reproductive specialists to ask what I needed to do.  Now you could run hormone assays to see if there is functional ovarian tissue left, but if the dog is coming in heat every six months, you can be pretty sure there is functional ovarian tissue.

Here's the problem: it could be a piece of ovarian tissue the size of a pin-head.  The specialist told me that I could even have implanted some ovarian cells on the body wall by rubbing the ovary against it on the way out.  "Jeez, how am I going to find that?!" He told me to wait until she was sure enough in heat (flaming) and do an exploratory.  Look for a little tiny red thing that looks like ovary. It could be anywhere — the proverbial needle in a  haystack.

So, what happened, you may ask?  The owners asked, "Can she get pregnant?" and when they found she could not, they refused to allow the exploratory (even at my expense).  They decided to just live with it, and the dog lived a long and happy life, despite cycling every six months.  So, I'll never know if I could have found what I needed to.

Tinkerbell This is Tinkerbell.  She was spayed at six months old, and at seven years old has had heat cycles every six months.  And really, lately she hasn't been feeling all that great.  Several years ago, I told her owner what it would take to look for the little tiny piece of ovary and she decided not to do it.  Lately, though it had started to bother both Tinkerbell and her mom more and more, so she said, "We'll do it the next time she comes in heat."

I must say that I had some misgivings.  I had told Mom that I wasn't sure I'd be able to find what we were looking for, even with the dog in heat.  It could be so tiny.  And it could be anywhere in there… I thought.

Uterine remnant What I had not counted upon was that whoever did her surgery did an incredibly lousy job… unbelievable, really.  This picture shows a piece of ovary on the right, removed from the usual ovary location.  On the left, also attached to a usual ovary location, we have an entire ovary, which you can't see because it's behind that big thing that looks like a Vienna Sausage.  The "thing" is a section of uterus that is full of pus, sort of a pocket-sized pyometra. It was bigger than her kidney or her colon, and when I first looked at it, I couldn't imagine what it was.  It just didn't occur to me that a surgeon could have left that much uterus in place. 

So, while it was hard to believe, it wasn't all that hard to find.  I sent the tissue off to the pathologist, thinking it must be a tumor or something, but it wasn't.  "Ovary and uterus, filled with pus".  The good news is that Tinkerbell feels better than she has in a long time.

44 thoughts on “Spayed female dog still having “heat cycles”?!

  1. Doc says:

    Hello, Janet,

    She didn’t regenerate her ovaries. The previous surgeon must have been impaired when the surgery was done. The tissue just hadn’t been removed in the first place. The dog had been having regular heat cycles ever since the surgery.

  2. Melinda says:

    My three year old lab was spayed at one year old after yet prior to her second heat cycle. No further problems encountered until about six weeks ago we noticed her vulva swelling but no sign of discharge. The swelling subsided somewhat but now has swollen up again and she does have bloody discharge. Her appetite is normal but she has become sensitive to greasy foods and will vomit it up. Other than that she is pretty much her rambunctious self. Thoughts?

  3. Doc says:

    Hello, Melinda,
    You could have a bad urinary tract infection, an infection in the remaining stump of the uterus, a growth in the vagina (less likely in such a young dog).

    She needs a vaginal examination by your veterinarian.

  4. Monyce says:

    Is it possible if uterus either some or full is left in and the dog has hidden ovary or maybe like tinkerbell a whole one left in to get pregnant or would it be pyometra could it be mistaken as pregnancy

  5. Doc says:

    Hello, Monyce,

    Your question is a little difficult to read, due to the run-on sentence and lack of punctuation.

    It seems that you are asking two questions.

    The first seems to be: If the dog has a whole or partial ovary, and a partial uterus, could it get pregnant?

    I think the answer is yes. There is a condition called “ectopic pregnancy” where the egg gets fertilized, but somehow doesn’t make it to the uterus, and just attaches to some other surface in the abdomen and grows to a pregnancy without even being in the uterus. So I think it could certainly happen under the above circumstances.

    The second question seems to be: Could a pyometra occur in these circumstances, and could it be mistaken for a pregnancy? Again, I wold say the answer is yes. An ultrasound exam would show fluid in the case of a pyometra, and a fetus in the case of a pregnancy. Ultrasound would be my diagnostic tool of choice.

    There is a really funny book on punctuation that I highly recommend:

  6. Madeline Aponte says:

    I have a yorkie and at 51/2 months she was spaded, now she is a year old and now lately she’s been humping like a male dog on my granddaughters leg does this mean she might have something was left inside too.

  7. Doc says:

    Hello, Madeline,
    That type of behavior can be related to the dog trying to assert dominance, and should not be tolerated. It is not due to hormones.

  8. Sandra Walden says:

    My female boxer has been spayed when she was 8months old. She is 5 years old andis chewing her way out of her pen. Found her with a male dog doing their thing.

  9. Doc says:

    Hello, Sandra,

    I think it would be wise to let your veterinarian check a vaginal cytology for signs of heat, and possibly check hormone levels.

    It is possible to leave an extremely tiny piece of ovary inside the dog (smaller than a pinhead, even) and see the dog having heat cycles.

  10. Jenny says:

    My 9 year old bitch is due to have a laparoscopic spay and a small pea sized mammary tumour removed. Unfortunately,she is due in season over the next few weeks. I am obviously concerned but, particularly because of the risks of removing swollen/ripe ovaries. Is she at higher risk of having a retained part of ovaries because she is so close to her season?

  11. Doc says:

    Hello, Jenny,
    You should discuss this matter with your surgeon.

    If she is in season, the ovaries will be enlarged (easier to find), but so will all the blood vessels in the area. It generally takes more time to do additional ligations (tying off) on the blood vessels.

    With laparoscopic surgery, you won’t have to deal with the larger abdominal incision that is usually performed, so that’ great.

    I don’t think there is greater risk of leaving some ovary, but the surgery will be a little more complicated, just as it would be with conventional surgical techniques.

    Again, you should discuss your concerns with your surgeon. I have no experience or expertise in laparoscopic procedures.

  12. Jaime says:

    We have a 1 year old female who has. Even spayed. We just brought in a 3 year old male who has not been fixed. He will not stop lucky her female parts. Quite obsessed actually. He has also tried to mount her. She has always been an overly attentive dog to herself with licking and cleaning. Is there a possibility more is going on with her. I have never noticed heat cycles. But she only turned 1 in October. So we may have missed 1 heat cycle and not known it.

  13. Doc says:

    Hello, Jaime,
    Sometimes this occurs if there is a urinary tract infection.

    I would recommend that you let your veterinarian check a vaginal exam and a urinalysis.

  14. mrs.kristi franks says:

    can that be swollen and hard? Penny was spayed 1yr ago cum march and is having heat cycle now. she is swollen and its kinda hard. cud that be wat ur talking about sum of reproduction left in after her spay

  15. Doc says:

    Hello, Mrs. Kristi,
    The vulva (external female parts) usually do become swollen and enlarged during a heat cycle. Because of the swelling, the tissue would probably feel firmer than what you would be used to.

    If she is also having a bloody vaginal discharge, it is possible she is having a cycle. You should have her checked by your veterinarian.

  16. Kim says:

    My 9 year old was spayed at 1. I noticed yesterday, my nuetered male, 5 years old, was wining and sniffing her as well as following her around all day. She acts fine. Just irritated with him. No discharge from her at all. No swelling either. Any thoughts on this?

  17. Doc says:

    Hello, Kim,

    It is unlikely that there is remnant of the ovary. You would have seen signs long before this.

    Sometimes a urinary tract infection will produce enough odor to interest a male. Usually you would see some signs of unhappy urination – frequent squatting, etc.

    If it continues, I’d ask your veterinarian to check her out.

    Rarely you get some sort of tumor that produces hormones.

  18. Donna Shanahan says:

    I adopted an almost 2 yr old chihuahua who had recently been in heat. (She also had an accidental litter at about 1 yr old). I had her spayed soon after getting her and here we are, 6 months since she had her last heat and about 4-1/2 months since being spayed and she’s humping a stuffed toy frequently and being aggressive. Do you think she is in some kind of heat?

  19. Doc says:

    Hello, Donna,

    This sounds more like a behavioral thing than a hormonal thing. Even spayed female dogs may mount one another as a dominance behavior.

    I would recommend doing some obedience training to give her something constructive to occupy her mind.

  20. tamyra spores says:

    My dog was spayed a little over 1 year ago she is having heat cycles with full 2 week blood discharge the vets are giving me the run around as what to do not a utility checked for that if something was left behind is it a health risk to her and would she have that much discharge of blood

  21. Doc says:

    Hello, Tamyra,

    If even a tiny, pin-head sized piece of ovary has been left behind, the dog can have regular heat cycles. I have been told by a specialist (when this happened to one of my patients) that it is possible to brush the ovary against the body wall during the surgery and accidentally implant a few cells.

    He told me to wait until the dog is in “flaming” heat and do an exploratory to look for the tissue.

    When the owners found that without her uterus she could not become pregnant, they declined to allow me to do the exploratory (even at my own expense).

    In the cases that I have been able to explore, another doctor had left substantial amounts of ovary behind and it was easy to find.

    It is also possible to have an infection in the stump of remaining uterine tissue, which is called a “stump pyometra”.

    A vaginal cytology examination should be able to differentiate between infection and an estrus cycle.

    I have also seen dogs who have bleeding disorders, and it is unrelated to the cycle. Also bleeding tumors in the vagina are possible.

    A good vaginal exam and vaginal cytology examination should help determine which direction to go.

  22. Amanda Keith says:

    I rescued my maltipoo 3 years ago and the rescue owner said she was not spayed. So I took her the get spayed and they opened her up and said she didn’t have a uterus and she must have been fixed. Not sure if they looked for ovaries but sewed her up and said she either was not born with one or the rescue home was not informed by previous owner. About 8 months into getting her she would go through these spells of going to a corner and licking herself excessively and whining, her vulva and teets also swell. I have taken her to the vet several times who just treat her for UTI even though her urine is not terribly infected. She continues to have this behavior about every 3-4 months. She also pokes her but in the air when I pet her. What are your thoughts?

  23. Doc says:

    Hello, Amanda,
    The swelling of her vulva and teats are certainly suggestive of ovarian remnant syndrome.
    That is a fancy way of saying that a tiny piece of ovarian tissue is still present.

    I have been told by a specialist that you can have a piece of tissue as small as a pinhead that can make enough hormones to produce these outward signs.

    If I had to deal with this, I would want to see her when she next has an episode. Obtain an uncontaminated urine specimen by putting a needle into the bladder, and culture it. If no growth, that rules out a bladder infection.

    To find an ovarian remnant, you need to do your exploratory surgery when she is as much “in heat” as possible, as that would be the time that the tissue would be most noticeable.

    The problem is that it still may not be very noticeable.

    These are not fun cases.

  24. Bill Jones says:

    Thank you for posting this. Our 5 yr. old rescue Boxer has been having cycles every 6 months with some bleeding and obvious swelling. She’s just started dropping her rear into the face or our little neutered male Maltese. We were told she had been neutered and our vet saw clear evidence of the normal scar. After reading your post it seems obvious what’s happened. We’ll be off to the vet tomorrow hoping to conclude this with a successful operation.

  25. Deana says:

    Hi, Our 9 year old dachshund named Lucy was spayed when she was a year old. We have a 4 month old male husky now named Tiberius. Lucy seems to be emitting a strange smell. My husband thinks she’s in heat though we haven’t really seen any evidence of it. Then again, she’s the only female dog we’ve ever had. She doesn’t seem to be acting any different to me. Any ideas?

  26. Doc says:

    Hello, Deana,

    I think it is unlikely that your dog is coming into heat if she went 8 years without doing so.

    If there is an odor, we usually check mouth, skin, ears, and anal sacs.

    A trip to your veterinarian may be needed.

  27. says:

    hi there, my female dog was spayed 6 months ago – shes one years old. Today a dog got into our garden and mated with her (and even got stuck). I’m now worried – She seems fine but is this normal? She has been bleeding a tiny bit over the last 2 weeks

  28. Doc says:

    Hello, Sharron,

    I would recommend that you see your veterinarian for a vaginal cytology examination to see if there is any indication that she is actually having a heat cycle.

    Ordinarily a spayed female would not allow mating (though rape is possible). But the bleeding in the previous two weeks makes me worry that a tiny bit of ovarian tissue may have been left behind.

    She wouldn’t be able to get pregnant, but she would continue to cycle.

    Your veterinarian can do a vaginal cytology exam quickly in the office and get an idea about this.

  29. Micheal says:

    Hi, my two year old lab mix was spayed when I adopted her at 3 months by the shelter I got her from. I have noticed that she is now bleeding and showing some signs of being in heat. I really don’t want to put the thru surgery, however I don’t want this to go on either. What should I do?

  30. Doc says:

    Hello, Michael,

    The first thing I would do would be to have your veterinarian examine her. He/she can perform a vaginal cytology examination to see if the dog is really having a heat cycle. There might be something else going on that has nothing to do with a heat cycle.

  31. Susan Davis says:

    You don’t have to publish this. I just wanted to say thank you for the time you took to answer some of these questions. I also wanted to tell you, I laughed so hard at the link you left someone that had typed a whole paragraph without punctuations. The sentence just went on and on and on!! That made me laugh…I think you are wonderful!!!!

  32. Cynthia says:

    Ummmm, yeah I am freaking out because my chocolate lab that I had fixed a year ago is suddenly in heat and I have one intact little male dog in my house going crazy, when she was spayed they did say they could not get all of her ovary, too close to spine, they never mentioned she could still go in heat, so I am really confused, guess I will call tomorrow, and find out if they even removed her uterus, or I will have an unplanned pregnancy
    So upset right now!

  33. Doc says:

    Hello, Cynthia,

    The best thing about this bad situation is that there should be a record of which side has a portion of ovary left behind, so you know where to look. Also, it’s going to be a big enough chunk to find, rather than some pin-head sized remnant that will be darn near impossible to locate.

    It will still be best to do surgery to locate it while the dog is in strong heat, as the tissue will be most visible then.

    Unless you can live with her continuing to cycle, somebody is going to have to go in and find that thing.

  34. Edie says:

    My greyhound bitch age 5yrs was spayed in March and she has now started rubbing up against me all the time.
    Is this natural?

  35. Doc says:

    Hello, Edie,

    This is not a common occurrence. I would look for other stressful things in her life that might be causing her to look for comfort with more physical contact.

  36. Lesley gisbourne says:

    Hi I have a 10 year old sheppard had her spade 6 months agof and as blood coming from her vigina she had pymetra and had an emergency operation if part of ovary was left in will it harm her I don’t want her to go through an operation again it cost us nearly 1000 pounds should we pay again or is it the vets fault

  37. Doc says:

    Hello, Lesley,

    The first step would to have a vainal examination performed. Examination and cytology examination should differentiate between a dog who is having heat cycles, and a dog who is having a discharge for some other reason (like infection in the remaining stump of the uterus).

    Also at her age, she could even have grown a polyp or tumor in her vagina that is responsible for the bleeding.

    If the vaginal cytology suggests that she is actually having heat cycles, then hormone levels can be measured to confirm that she still has ovarian activity.

    If there is an ovarian remnant, then your veterinarian needs to know that.

    It could be something else.

    First step is examination and cytology of the vagina.

  38. Stephanie Donnelly says:

    My female was spayed after 2 cycles… every 4-6 months she gets a weird odor. No pink discharge. We now have a 2.5 yr old male dog still in tact and out of nowhere he is persistently irritating her and trying to jump on her, whining and panting all the time! Question is could she be going into heat or giving off a scent but not discharging?
    Is that possible?

  39. Doc says:

    Hello, Stephanie,

    That would be unusual. Your veterinarian can check hormone levels when she does this to verify whether there is ovarian activity.

  40. Becky Coulter says:

    My 7-month old chihuahua was spayed 2 days ago. She tries to poop, but it hurts her too much, so she hasn’t pooped since her surgery. She must have waste in her bowels and I’m worried it could hurt her. Is there anything I can do do help soften her poop so she doesn’t have to strain or push to get it out?

  41. Doc says:

    Hello, Becky,
    I hope you have been able to contact your veterinarian by now. It is very safe to mix 1 teaspoon per 20 pounds of dog (and I’ll bet you won’t need that much, with a Chihuahua) of plain metamucil (psyllium) with each feeding.

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