Oxytocin is a tremendously useful tool for whelping, as long as you follow one simple rule: Is your bitch whelping? THEN DON’T USE OXYTOCIN.
Oxytocin is a drug that used to be considered absolutely standard during whelping. One or two mls (ccs) used to be given to each bitch, several times during a whelping. Then, maybe ten years ago, researchers realized that the large doses were overwhelming the oxytocin receptors in the smooth muscle of the uterus, and actually causing a failure to contract. So conventional wisdom changed to recommend tiny micro-doses of oxytocin. So one-tenth cc doses became common.
And now, after breeders and vets realized that it was not as harmless as everyone had assumed, we’ve come full circle. Evidence does not bear out oxytocin’s use at all, as long as there are still puppies inside the bitch.
The very good reason that the best protocol now says not to use it at all is that oxytocin causes hard, consistent contractions. But the canine uterus is not SUPPOSED to contract in the hard and consistent way that oxytocin forces it to do. The uterus is supposed to handle multiple puppies, gently moving itself toward the vaginal opening. Imagine it like a pair of panty hose that you are you are gathering up. As you gently fold the material, the toe moves up toward the top of the hose and the entire length of the leg shortens.
If you picture three or four puppies lined up along the length of the leg of the hose, each puppy will be pushed out in turn, but the hose behind that puppy will stay soft and relaxed. Then the next puppy will be moved up, and the next, and the next. The last puppy moves out as the toe of the hose comes up to the waistband.
Now imagine that instead of gathering the hose, you make the whole thing clamp down on itself while it’s still stretched out. Now instead of the puppies being in soft fabric, they’re in shrink-wrap. That’s what oxytocin administration does; it contracts the entire uterus HARD, so puppies are squeezed tightly along the entire uterus.
In addition to not being very effective at moving puppies upward, these hard contractions cause the placentas of all the puppies to detach from the uterine wall. What should happen is that only the puppy closest to the vaginal vault detaches, so it only has to move a few inches to get out before its oxygen runs out. Puppies are tremendously flexible when it comes to oxygen needs, and a puppy can be detached from its placenta for ten or twenty minutes minutes before it is in danger. There’s plenty of time to get through the cervix and out, even if the contractions are infrequent.
When you use oxytocin, the placentas of the further-back puppies detach too. They cannot make it to the outside fast enough, and they die. A normal labor can actually go on for over 24 hours and the puppies will still be fine; puppies’ sacs can break and they’ll be fine; puppies can be half-way through the cervix and still be fine. What kills them is when the placenta detaches. The clock starts ticking, and you’ve got to get them out within about twenty minutes or they will not be able to be revived.
The only thing that’s safe to use when there are still puppies in the uterus is CALCIUM. Most cases of uterine inertia are caused by low calcium, not low oxytocin. Calcium allows the bitch’s body to keep contracting at the normal pace, at the normal strength, and won’t kill puppies. Oral-cal-plus or (at your vet’s office) IV calcium will start stalled labors if they’re meant to be started again. If you can’t get the whelping going again using calcium, go for the c-section. You’ll end up with live puppies and a healthy uterus.
A ton of vets are still using oxytocin; a ton of them are still using it at the old one-cc dose! You need to be the best advocate for your bitch and STOP THEM.
And yes, I’ve used it. Lots. And I’ve lost puppies. Far more than I should. And I’ve brought a bitch to be opened up for a c-section and found the puppies literally shrink-wrapped inside her. It’s only in the last five years or so that the protocol has changed, and I was as astonished (and quick to deny it) as anyone. But it switched for a very good reason, and it will save a lot of puppies if we are willing to change our practices.
Now remember that I said at the beginning that oxytocin is still a useful tool – and it is. It’s there for you if the LAST puppy needs a little boost over the last inch (once the nose can be felt in the vagina), or to contract the uterus once whelping is over. Once the puppies are out, the uterus needs to clamp down strongly to stop from bleeding, which can be difficult if the bitch is tired or still has some placental tissue inside. So do use it if she’s bleeding more than she should be or if you’re concerned that she retained a placenta. Otherwise, leave oxytocin on the shelf where it belongs.