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Oxytocin, Calcium and Glucose

Oxytocin, Calcium and Glucose play an important role in the whelping process. They work hand in hand in the delivery of puppies.

Oxytocin is a complex hormone that has three basic actions. It’s a naturally occurring hormone manufactured in the hypothalamus gland and stored in the pituitary gland until required by the bitch. It can be synthetically produced and given as an injection to the bitch. It has several uses in the canine reproductive process. To understand just how oxytocin works you must understand the way that muscles work in the mammal.

There are two types of muscle tissue: “striated muscle”, which comprises all the muscles in your body over which you have physical control. You can walk, open a jar, pick up a ball. The other type is called “smooth muscle”. You have no control over these muscles. You can not make your uterus contract, you can not make your heart beat. When you sleep it’s the smooth muscle that keeps you breathing.

Oxytocin is a selective hormone that causes the contractibility of the smooth muscle in only two locations, the uterus and the milk glands. Terbutaline is a drug that causes the relaxation of the uterus, heart and lungs.

Oxytocin is used to increase the quality of contractions during labor by increasing frequency and duration.

Oxytocin alters the cell membrane of the uterine cells so that calcium can enter the uterine cells during labor thus causing stronger and more effective contractions.

Oxtocin is used as a clean out shot following delivery.

Oxtocin is the hormone responsible for milk letdown and milk ejection during breast feeding. As puppies nurse oxytocin is released from the mother’s pituitary gland causing contraction of the breast tissue allowing milk to be released to the puppies.

Oxtocin also causes mild uterine contractions causing the involution (return to pre-gestational size) of the uterus following delivery every time the puppies nurse for several days.

Oxytocin is produced synthetically and is used in human medicine under the name of Pitocin. This is used to induce labor in humans. It is very effective for induction in humans and mares, but has not been found to be useful in cows, ewes, does or sows. It is not known if Oxytocin can induce normal labor in a full term bitch. DO NOT USE IT TO INDUCE LABOR.

Oxytocin during labor

Oxytocin is used to facilitate more effective labor during whelping. It is responsible for the frequency and duration of the contractions. It is also responsible for the timing of the contractions. Place your hand to feel the uterine muscle as it contracts, you can get a reliable idea of when the contractions are occurring and how long they are lasting. Oxytocin is a very useful drug but it can be very dangerous if given inappropriately. Your vet will be the best resource to learn how utilize oxytocin for whelping that is safe for both mom and puppies.

Oxytocin as a ”clean out” injection:

Oxytocin is used after the whelping process as a “clean out” to cause the uterine contractions that will cause expulsion of after-delivery tissues, blood and blood clots. Recent studies have suggested that the use of oxytocin as a clean out shot is associated with prevention of mastitis in the bitch. They are much less likely to develop mastitis. Talk with your vet to provide you with oxytocin prior to whelping and how to give it to your bitch.

Oxytocin for milk ejection:

As puppies begin to nurse the pituitary gland will secrete small amount of oxytocin to encourage the milk letdown reflex and cause the ejection of milk. Oxytocin also causes mild uterine contractions that will cause involution (returning to the pre-gestational state) of the uterus and continue the clean out process. If your bitch does not get milk in you can have your vet give her 3 very small doses of oxytocin to encourage milk letdown.


Calcium is critical in the role of delivery of puppies. Decades ago it was almost unheard of for a bitch to have a c-section. Now it’s very common in many breeds. Some breeds c-sections is almost 100%. Why more c-sections? Breeders have selectively bred for certain features, like large heads combined with very small pelvises which has made c-sections necessary. The other reason that we see so many c-sections is because in an effort to do everything we can do to insure healthy moms and puppies we have supplement the bitch with Calcium. Some do it by feeding a raw meat diet, extra calcium tabs and some do it by increasing the intake of calcium rich foods during pregnancy. Many vets will recommend that you should keep her on a diet of puppy food that is very high in calcium. During the days when bitches delivered naturally most of the time fed their bitches a diet of talbe scraps, generic kibble or combination of both because that is all they had. They did not give calcium supplement just because at that time they were not available to them.

When you think of calcium most think about bones and teeth. Calcium is all about muscle contractibility. That is the most important role in our bodies. Calcium keeps our hearts beating, our legs muscles walking and your bitches uterus contracting when necessary. Calcium gives strength and intensity and oxytocin determines the frequency and duration of uterine contractions.

Calcium is stored in our bones. The release of calcium into the blood stream and regulated by the parathyroid gland. When we need extra calcium the parathyroid gland goes to work and pulls it out of the bones and puts it into the blood stream. The parathyroid gland is lazy and if someone else provides the calcium on a day to day basis it will go to sleep. So when we load our bitch down with extra calcium every day so the pup will have big strong bones the parathyroid gland will have not much to do and slacks off and no longer does much of anything. It takes a long vacation and then when the day comes for the puppies the parathyroid gland will not release the calcium to create good strong contractions. So sometimes giving extra calcium will do more harm than good and may even cause your bitch to have a c-section.

Once you have figured out that your bitch isn’t contracting as she should your vet may want to give her some oxytocin to help the contractions. Sometimes this may not help at all. When you have given to much calcium you have set her up were her body’s ability to utilize oxytocin is none. Oxytocin is the hormone that controls the rate of calcium that is allowed to enter the cells of the uterus. So the supplemented oxytocin will do no good if the parathyroid gland is on vacation. There is no extra calcium being sent into the blood stream. Think of it this way oxytocin opens the door for the calcium from the parathyroid gland and the parathyroid gland has a sign that reads gone fishing so no extra calcium is put into the blood stream to get the contractions to work.


Calsorb is a product containing calcium that is safe to use and easy to obtain on the internet. It’s a lear gel product packaged in a syringe to be given orally. If your bitch has been pushing for a while and nothing is happening you can give her about 3mls of Calsorb by mouth and it should strengthen the contractions. It isn’t unusual to see a puppy delivered within 10 minutes of given Calsorb. Calsorb doesn’t have any side effects of oxytocin and safe for mom and puppies. You should take your bitches heartbeats and keep a record. Normal heart rate should be around 130-150 beats per minute. After giving a couple of doses of Calsorb check her heart rate. If her heart beat is over 15 beats or you hear a change in normal rhythm of the heart discontinue the Calsorb. Some bitches will often throw up after taking Calsorb.


Because most bitches lose their appetites the day of delivery and sometimes go with a meal for several hours it is good to have some Nutra Stat to give to her to make sure her glucose levels stay up. You can give her Nutra Stat from time to time and it will not hurt her or the puppies. This will keep her energy level high and it will get to the puppies in utero. If a puppy has not been ale to nurse from mom for the first two hours you can tube feed half the weight of the two hour puppy mixed in ounces of Pedialyte. If a puppy weighs 6ozs you would use 3ozs of Pedialyte. Usually it’s a one time thing and will nurse from mom. If you must repeat do it every 2-3 hours and change to milk substituted such as Esbilac.


I would like you to visualize the interdependent role of each of the components of whelping: oxytocin, calcium and glucose. They have been assigned a job that requires teamwork.

Oxytocin’s job is to regulate timing and rhythm so that things move forward as they should.

Calcium’s job is the strenght of the contractions.

Glucose provides the energy and endurance for the oxytocin and calcium to work.

If you have had needs for Glucose and Calcium by giving your bitches diet and nutrition , she will usually need oxytocin as well. They all work as a team.

Talk with your vet before your bitch gives birth if you are unsure of what would be the best for her. Don’t wait till the day she is giving birth.