UTERINE INERTIA during the whelping of a litter is “The failure to complete expelling of all fetuses, usually due to the exhaustion of the uterine muscle.”   

 [Two different whelpings of young, healthy bitches within ten weeks and considering Uterine Inertia] . The first bitch’s whelping history is “Hunter’s”. The discussion following for her is her second litter. I was asked to be there and assist  as I had also been there to help a year earlier at her first litter. Owned by a fabulous young couple, I met originally perhaps eight or nine years ago while assisting them in doing a side-by-side artificial insemination and semen analysis for their hunting bitch. The sire they brought had a field champion background and the dam was their hunting titled companion female.  Their veterinarian referred them to me for help and I was impressed at the time, with this couples excellent effort to obtain all soundness clearances and, also obtained working titles. With the stud dog having sperm problems, no litter resulted from my effort to help them with this breeding. The female was older and  hadn’t been bred before. Years later, this same couple came to me again after having  to put their old hunting girl down. They wanted to consider a better quality Labrador in acquiring any new puppy. We began a wonderful friendship, co-owning this wonderful chocolate sister to my dog. We have trained together, shared many dinners, and  continue to learn many things as we encourage each other, and as we participate in this sport we truly love.

 Her first beautifully bred litter that I assisted with, was eleven large and typey puppies. The sire was  carefully selected for a strong pedigree to combine with the bitch’s, and with a strong desire to produce puppies that were beautiful structured, typey, and also knowing that each dog was perfectly sound. At the couple’s home, they had a room extended from the kitchen. There was his beautiful whelping box with multiple exercise pens attached to each other, making a very nice and functional surrounding area to mom and for the puppies to explore and play in eventually. Heat lamp is set up very nicely and yet we are sitting outside in the room area near her favorite gigantic doggy pillow and her chosen place to lie.  The young owners, who are now my very good friends, are trying to do their very best in anything they enter into, as they get more involved with their chocolate girl. We have had really amazing times birthing this girl together and in-between puppies, enjoy sharing stories and answering questions.

 We have the responsibility to manage the pregnant bitch’s weight and condition during her pregnancy. A long and vigorous walk every day is essential, assists the bitch staying in good tone and prevents her getting too fat. A fat bitch may have her uterus stretch, which can interfere with its ability to contract. Fatty infiltration of the uterine muscle, will lead to insufficient contractions. It is proven that the hormones involved in the delivery process, work sluggishly in fat tissue. The chubby bitch may have a difficult time birthing because of either delays in RECEIVING the hormonal messages OR have a weak response to the necessary birthing hormones.

 STRESS for the mom birthing interferes with hormone interaction during birth. Oxytocin is the hormone responsible for uterine contractions and milk let-down during nursing. When the bitch is stressed, Epinephrine is produced and it interferes with hormone interaction. Over anxious owners who make lots of  noise, fuss constantly and when there are children present, cause stress for the some bitches during birthing. Do your best to keep stresses to a real minimum.

 I must admit that I'm wondering about doing the x-ray five days before the bitch’s  due date ‘to count puppies’, as the count is so often wrong. ‘The x-ray at 55 days’ IS a good appointment time to have a simple digital exam of the birth canal done by the veterinarian, to check for obvious issues such as malpositioning.  The x-rays should be put up and examined by yourself and the veterinarian and the time taken to circle skulls, count puppies, and to check for obvious blockages.

For “Hunter”, a radiograph was done by my young couple and it showed “Eight or more”.  This three year old female’s (“Hunter’s”), first birthing experience one year ago was such that she had no problems birthing at all and it was very easy for her.

Keep good records of Progesterone levels, Dates for when she is was progesterone level between 5-10 ng/ml (Ovulation),   Date for 63 days WHEN birthing is due. Doing a 33 day ultrasound from Ovulation, can confirm pregnancy, but NOT count puppies. We discussed their taking her temperature every day the week before she was due and watch for it to fall from 101.5 to 99.0 knowing that usually the bitch will begin birthing twenty-four hours after staying at temp 99 degrees.

 Normal Birthing has 3 stages and understanding these will reduce anxiety and panic. Early labor averages six – twelve hours but can be as long as 36. The bitch is basically restless and may show nesting behavior but Isn’t Contracting. (This second birthing for “Hunter” was her first to tear up a really nice blanket inside the whelping box; she shredded it during her first eight hours of labor.) Every hour, we would put her on a lead and walk her outside (With a towel over our shoulder !)

The position of squatting to urinate is a perfect position for her to bear down on a puppy in the birth canal. The big squatting position aids pushing and the walking helps move her forward.  

PRIMARY UTERINE INERTIA is fairly rare but we need to know what to watch for as it can be very real and, with birthing often falling at night and or on weekends and holidays, do be aware of the sympton.  Primary uterine inertia is the FAILURE TO EXPELL A PUPPY; not going into normal labor and having contractions at or after 63 days from KNOWN OVULATION.

 The bitch owners and I talked for many hours during stage one of “Hunter’s labor, and shared really good cups of coffee. (During this Stage One of Labor, the bitch may not eat and may become restless, nervous, pant from time-to-time and, even tremble.   STAGE TWO of labor is the stage of pushing the puppies out and Stage 3, delivering the placentas.

She did progress to her Pushing Stage just about twelve hours from when she first leaked some clear fluid from behind and started showing signs of Early labor. When the bitch begins to push, NORMALLY, the bitch strains and muscles contract. This pushes the puppies into the birth canal.  We finally saw her progress to giving good contractions. Coming into the bitch’s cervix causes the uterine contractions that then follow. Her efforts to push on her bed and blanket between our two chairs, didn’t seems to be producing a puppy. (The whelping bitch should not push for more than 30 minutes without producing a puppy).   We put a lead on her and walked her outside. She squatted and seemed to then have long and productive contractions. A puppy came into the birth canal and was easily seen presenting at the end of the puffy vulva. It still wasn’t coming out but it was half presented- I put a towel (rough and dry against the slimy baby), around the puppy and gave a gentle pull downward. We had a huge baby and the process caused the umbilical cord to detach; we clamped the cord about an inch from the baby’s belly, tied it there with dental floss and then trimmed the cord. Mama and baby spent quality time together in the whelping box, and as the the puppy was nursing; the mom’s body was making more oxytocin to start the next pattern of contractions.

 Her second puppy came within about a half-hour and the third, about an hour from the second. We kept a ‘log’ of time of birth, puppy’s sex and any notes specific to each puppy’s birth so we could know especially, how long it was between puppies.

SECONDARY INERTIA is very common and can simply be caused by muscle fatigue from either a larger litter that has stretched out the uterus or previous large litters for this bitch. Most often part of the cause of Secondary Inertia is simply the bitch becomes exhausted and needs help to finish. WHEN THE BITCH STOPS CONTRACTING PART WAY THROUGH birthing the litter, Secondary Uterine Inertia should be suspected.

 At whelping, a puppy could become malpositioned because of being stuck behind Vertical Bands in the vagina or Strictures; they can be identified with a gloved finger exam even at the time of doing an A.I., or at a pre-whelping exam. Both head first and breech puppy presentation is normal in dogs. Puppies positioned in a side-ways position, positioned with the fetus backbone aligned with the top surface of the uterus or a mismatch between the size of the birth canal and the puppies themselves can cause a halt in labor and will require Veterinary Intervention. IF More than two hours have passed and she appears to fall asleep, isn’t contracting with purpose, and she has been walked without producing a puppy, she needs to be examined to determine IF there is a puppy blocking.

Occasionally, a ONE or TWO Puppy Litter may lead to insufficient hormonal stimulation to bring on the necessary contractions to produce the next puppy. This would be a cause of secondary inertia; at a pre whelp exam, possible problems with birthing a very small litter can be discussed.

   Calcium is essential for proper contractions of all of the muscles and including the uterine muscle. Calcium is an intracellular signaling molecule for muscle contraction. One common cause of Secondary Uterine Inertia is Hypocalcemia, a drop in the levels of calcium throughout the body and some breeds or lines within a breed, may have inherited weakness of the uterine muscle. . The presence of intracellular calcium causes contraction and its removal allows the muscle to relax. A drop in the level of calcium inside the muscle fiber, makes the muscle relax.

 IF Secondary Inertia is suspected, and the bitch is walked at an hour between puppies, but she comes back to her area and just stops labor, she may be experiencing Inertia.  Knowing that there are more puppies to come and a finger exam didn’t show any puppy stuck, I have learned that giving a micro dose of Oxytocin can produce productive contractions (IF the uterine muscle is still strong), and bring forth the next puppy.  I’ve seen nothing happen also. In that response from the muscle, intervention is needed. We gave calcium tablets but the time to go through the digestive system and then the small amount in her blood stream would have little impact on her uterus. This lovely chocolate girl went all night having produced five of her nine puppies but she then just stopped at just an hour until his vet was open. The veterinarian x-rayed to show more puppies; he didn’t have IV calcium, and tried oxytoicin. She then had a c-section to deliver dead puppies.  

When the muscle is truly fatigued, it cannot contract anymore.  The (uterine), muscle must be replenished first with calcium before oxytocin will produce a contraction. It can be contracted or fired to a point of not having the nutrients in the muscle fibers to assist the birthing hormone (oxytocin), making contactions.

Two months later, I was able to assist another whelping of a first litter from a beautiful yellow daughter of my older yellow champion. The family who own this bitch are an hour plus South of me and live no-where near a clinic. When this lovely bitch in excellent condition went into labor, I drove down to their place to assist as best I could. It happened to be a Sunday, of course. I had decided to obtain Calcium Gluconate 10% and brought some oxytocin as well. This first time mom was doing great and had delivered six puppies, primarily while walking outside as she seemed to like squatting freely out-there. Then, she seemed to lie down and just go to sleep. At an hour from the last puppy, we put her on a lead and walked her again but nothing. She came inside and just lay down and went to sleep. No signs of discomfort, just no contractions from the uterine muscle. We knew she had more puppies.  At two hours from the last puppy, I put a tourniquet on the forearm and gave Calcium Gluconate 10% / 1cc per 30 lb body weight, IV. Amazingly, within less than a minute, she was pushing beautifully and out came the next live puppy! This particular female had three more, and then seemed to be in Inertia again. She was walked and walked but would not contract; she would want to lie down and rest. A second therapy of Calcium Gluconate she began squatting and expelling her last puppy.  She whelped eleven puppies for a first litter! - - - I am Not suggesting owners/breeders try injecting their birthing dogs; I nursed for many years, drew blood for persons daily and am confident giving injections. When you suspect Inertia, seeing that labor has seemed to just stop, you should contact the veterinarian you had your pre-whelping exam and x-ray with.

Calcium therapy suggests that  IF there is no response from the Calcium Gluconate in 45 minutes, follow the Calcium with 1-2 units of Oxytocin and one more dose of Calcium. Again with no response in 45 minutes, a C-section is probably the best treatment. Prolonged dystocia will usually result in bitch exhaustion and death of fetuses.

Owners should consult with their veterinarian prior to breeding a female who has had inertia problems in the past. Using Calcium IV can restore the contracting ability of the uterus and might be tried before just jumping into a section.  The critical management part in preparing for a smooth whelping is to have your breeding dates and information accurate and a good plan with your veterinarian should you face Inertia problems. Remember also to keep your pregnant girl exercised, moderately at the end of the pregnancy and keep her weight healthy. Understanding the uterus as a muscle may help prevent unnecessary c-sections by trying Calcium/Oxytocin therapy first (after knowing there is not an obstruction), before just jumping into a C-section. We’ll also want to be aware of how Inertia can become a problem during the whelping of our precious litters and how we can also be more prepared for it.    

REFERENCES:

Louisiana State University Veterinary School