Improper cervical dilation at calving demands quick action

Beef 911: This is one of the hardest situations that comes during calving and recognizing the problem is the first step

One of the hardest calving dilemmas you face as producers, or we face as veterinarians, is improper cervical dilation.

When going through the stages of labour before expulsion of the fetus, the cervix relaxes, softens, and opens up (essentially as wide as the vagina) to allow the fetus to enter the vaginal vault. When this does not happen normally, or is delayed, the health of the fetus and dam may be in jeopardy.

If one were to examine a close-to-term pregnancy, the cervix is to the front of the vagina and the opening is normally about one to two fingers wide. It would be like sticking your finger in a doughnut. So when a cow is straining somewhat and you do a vaginal exam and find this condition, what is your next step?

First off, I hope you have fully cleaned the cow’s back end, used OB sleeves, and an approved lubricant. The very act of examining her may initiate a small degree of straining that may look like she’s calving, so be gentle.

What I do in these situations — if I think a cow is calving and find a closed cervix — is re-examine her a couple of hours later. If I find the cervical opening has increased, that tells me calving is progressing. If there is no change, you now have to decide if this is a false alarm or an early indication that there is a problem. For example, her vagina could be prolapsing.

At this juncture, some vets may have you give the cow more time and some may opt to perform a caesarean section. Each case is different.

Another issue involves a cervix that will only open wide enough to get the front two legs through. This is not common but does require different interventions depending on how it is progressing.

In a normal birth, the cervix is right out of the way when we get to the expulsion of the fetus. When it isn’t, we have a dystocia and the veterinarian will first try to dilate the cervix manually to facilitate delivery.

If the nose and head can be partially delivered, a slight amount of traction may help dilate the cervix fully. This is where one has to be really careful as too much traction is both stressful on the calf and may rip the cervix causing excessive bleeding and possibly be fatal to the cow. If no progress is made, a caesarean section is performed to get a live calf, and save the cow (but she should be marked for shipping the next year). Usually the fetal membranes can be passed through a partially opened cervix.

Some of these cows with a partially opened cervix may have had a difficult calving the year before which caused some damage to the cervix.

Even though there is a lot of room in the pelvis and vaginal opening, C-sections are the only solution for a cervix that won’t dilate. As mentioned a forced extraction through a partially open cervix puts both the cow and calf’s life in jeopardy so a C-section is a win-win solution most times.

You can usually tell if the cervix will open with just some manual dilation. They are soft and supple, and you make progress getting them to open more after 10 or 15 minutes. If the cervix has a hard fibrous feel, no amount of time will get it to open up so jumping to a C-section hopefully will be in time to have a good result for cow and calf.

There are a couple of other instances where a partially closed cervix will be encountered.

After correcting a torsed uterus, your veterinarian may encounter a partially closed cervix. Because of the twist, the cervix cannot fully dilate but upon correction it can generally be dilated by hand. There is a tendency to let it dilate on its own, but I have done that and ran out of time resulting in a stillborn calf. Now I proceed to dilate the cervix manually to facilitate extraction. Generally these cervices are soft and supple, and in my experience easy to dilate.

The other condition is a delayed calving that results in death and an emphysematous fetus. This could be because of a malpresentation, such as a breech birth where the cervix is opened, straining does not ensue, time runs out, the calf dies, bloats up and straining ensues. Often the cervix can start to close up, much as it would after a normal calving. These cases may require a fetotomy or partial fetotomy, in order to salvage the cow.

Although infrequent, partial cervical dilation does require serious intervention by either yourself or your veterinarian depending on your level of experience.

Recognizing them is the first step. If you think a cow is in labour and no progress is being made, don’t hesitate to do a vaginal exam as improper cervical dilation may be a cause.

By recognizing it early you have the time to intervene, and provide a favourable outcome. Have a great 2018 calving season everyone.

About the author


Roy Lewis practised large-animal veterinary medicine for more than 30 years and now works part time as a technical services veterinarian for Merck Animal Health.



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