Difficult calving (Dystocia) in cattle

Dr W J Grobler BVSc.


The calving process consists of three stages:

  1. Relaxation of the cervix
  2. Birth of the calf
  3. Expulsion of the afterbirth (placenta)

In heifers the process could take up to four hours, but in cows it shouldn't take longer than an hour and a half.  During the first part the animal will appear uncomfortable and will lie down frequently.  When the cervix is fully dilated, the calf's front hooves start moving through (see figure below).  This action stimulates the release of a hormone, Oxytocin, by the brain that further stimulates contraction of the uterus.  A cycle of dilation and contraction develops that helps the calf on its way out, while the cow contributes by bearing down with her strong abdominal muscles.  The afterbirth is expelled within four hours after the birth of the calf.  If all else is normal, the uterus will decrease in size over the next four to six weeks, during which time a small amount of reddish-brown mucoid (slimy) discharge is normal — this is the excess tissue formed during pregnancy that is excreted.

The normal posture of the calf during calving

The following problems could lead to dystocia:

  1. Small pelvis relative to the size of the calf.
  2. Calf too big relative to the pelvis.
  3. Calf in incorrect posture.
  4. Torsion of the uterus.
  5. Insufficient dilation of the cervix.
  6. Twin calves.
  7. Abnormal calves.
  8. Milk fever especially in dairy cows.
  9. Prolapse of the cervix.

All of the above problems are discussed in some detail below.

Small pelvis relative to the size of the calf.

The most common reason for a small pelvis is when heifers are bred too early.  This is usually due to poor management, but the neighbour's eager bull may also play a role.  Animals in poor condition at calving may also be at risk due to weakened abdominal muscles.  In most of these cases an experienced person may be able to deliver the calf, but sometimes a caesarian is the only way out.

Calf too big relative to the pelvis.

The two main reasons for this is the use of bulls producing high birth weights and overfeeding of cows especially during the last three months of pregnancy.  In the latter instance these calves grow too big and more fat is laid down inside the pelvis thus decreasing the space therein.  Both of the above causes for dystocia could lead to the next one:

Calf in incorrect posture.

The normal position for the calf due to be born is in an upright position with the head and front feet pointing towards the cow's rear.  The feet are one before the other and a few centimeters in front of the nose.  The feet and nose form a wedge that slowly stretches the cervix, leading to secretion of oxytocin and further contractions of the uterus.  A small number of calves are born back to front and in a large proportion of these cases the hind legs are turned away from the cervix, necessitating the help of a vet.

The most common abnormal postures are lateral deviation of the head and neck and flexion of one or both front legs.  In the first instance the head is turned away from the cervix (see figure below) and in the second one or both front legs are turned backwards.  The correction of these abnormal postures is best left to someone with experience since it usually will mean the administration of an epidural to stop the cow from bearing down.  In both cases the calf has to be pushed back into the uterus in order to rectify the calf's posture, but this is usually easier said than done because the animals keep on straining against your force.  As is mostly the case the earlier action is taken, the easier it is to help the animal, but in longstanding cases it may be necessary to cut a dead calf into smaller pieces — this is obviously a job for the professionals!

Lateral deviation of the head and neck

Torsion of the uterus.

The full term uterus weighs about 90kg and because it is strongly attached at the cervix only it could tilt over if the cow falls or is pushed suddenly.  This causes the closing off of the uterine exit thus preventing the calf from being born.  When the calf is due, the cow will bear down, but there will be no progress whatsoever.  The only practical way of solving this problem is by doing a caesarian as soon as possible.

Insufficient dilation of the cervix.

In a very small number of heifers the cervix doesn't dilate properly and a caesarian is the only way out.  It is also a possibility in older cows if during a previous calving the cervix was damaged to such an extent that a lot of fibrous tissue formed therein.

Twin calves.

If a cow has twins, the legs sometimes become entangled and the limbs of different calves could be inside the pelvis simultaneously.  Since there is only room for one calf at a time, careful manipulation is necessary to ascertain which limb goes where and to push the hindmost calf back before freeing the first one.

Abnormal calves.

Gross deformities may lead to enlarged parts of the calf, making birth impossible.  A dead calf may have to be cut into pieces or a caesarian may have to be performed.

Milk fever especially in dairy cows.

Milk fever usually develops three days after calving, but high producing cows may suffer from low calcium levels before calving.  Calcium plays an important role in the contraction of all muscles including those inside the uterine wall.  After the prompt and correct administration of calcium such an animal will quickly proceed to deliver her calf.

Prolapse of the cervix.

In cows with a lot of loose skin and large vulvae the cervix sometimes prolapses, usually because of some irritation e.g. cystitis.  If the animal isn't close to calving, the cervix has to be replaced and stitches put into the vulva to prevent recurrence.  The cow has to be kept under close supervision and the stitches removed as soon as she starts bearing down.  If the prolapse recurs during calving, an epidural anaesthetic is administered, the cervix replaced and the calf gently pulled.  In the majority of cases however the cervix doesn't dilate properly and a caesarian may become necessary.  After the calf has been delivered, preventative stitches are again placed to prevent further prolapse.

When should I seek help?

Because most animals will calve without trouble, a reasonable amount of time must be allowed — about four hours in the case of heifers and about an hour and a half in adult cows.  If however there is no progress within the allowed time, an experienced person should do an internal examination with properly disinfected hands to check the position of the calf's feet and head.  If the position is normal and the person's hands move freely around the calf's head, an attempt at pulling the calf may be initiated.  Stainless steel chains are preferred over ropes since they cause less trauma to the calf's feet.  Pulling should coincide with the pushing efforts of the cow, the one foot should always be in front of the other and at no time should excessive force be necessary.  The well-being of the calf and the cow is paramount and unnecessary suffering should be avoided at all times and if the efforts of two or three people not lead to any progress the help of a professional should be called for.

Incorrect pulling leading to wedging of the shoulders

Lubrication of the vagina and the calf is of the utmost importance!  There is no lubricant however as effective as the natural mucus produced by the placenta — an important reason why as little time as possible be wasted in helping the cow.  A disinfecting soap is a good alternative, but must be applied in copious quantities and repeated as often as necessary.

The forehead of the calf creates the most resistance at the pelvic inlet as well as at the vulva.  Be very careful that the vulva doesn't tear because a tear into the anus of the cow can end her reproductive career.  The hips can also become stuck so it is advisable to turn the calf's body 45 degrees to any side once the head is out.  This will ensure that the broadest part of the calf's hips (between the pinbones) not become wedged into the narrowest part of the cow's pelvis (the horisontal diameter).

Incorrect traction of the hind feet — the one foot should be a few centimeters in front

If the person doesn't make any progress within 20 to 30 minutes the help of a veterinarian should be sought.  No vet will mind doing a fresh calving, but it is very frustrating to try and deliver a dry, smelly calf if someone else has wrestled with it for a few hours or even a day.  Most of the time a little bit of experience can make a huge difference.

Top of page | Problems with calving

Complications of dystocia

  1. Retained placenta.
  2. Prolapse of the cervix or uterus.
  3. Uterine tears.
  4. Infection of the uterus.
  5. Partial paralysis of the hindquarters.
  6. Damage to the cervix.
  7. Uterine adhesions.
  8. Bleeding from the uterus.

All of these conditions are discussed in more detail below:

Retained placenta.

The placenta is deemed retained if it has not come loose within 12 hours after calving.  Unlike in horses and people, this condition isn't nearly as serious in cows.  The general well-being of the cow should be taken into account — if she is still grazing it is not as serious as if she were lethargic and clinically ill.

It is extremely important to work with retained placentas using strong gloves — contagious abortion (Brucellosis) is a very unpleasant disease that may be picked up from placentas and the uterine discharge following calving.  The part of the placenta hanging out should be twisted around a short twig while very gently pulling thereon.  It is very important that the placenta doesn't break, else you will not be able to judge if it has come out or not.  If the placenta doesn't come loose with the first attempt, pessaries should be placed inside the uterus according to the manufacturer's instructions.  The safest way of doing this is with a special applicator.  The next day another attempt is made,  but if you should have any queries at any stage, please contact your nearest veterinarian.

Antibiotics should be administered if the cow appears ill.  It is preferable to use the same or a similar antibiotic to that included in the pessaries so that the products could work together to fight infection.  Please contact your vet for advice in this regard.

Prolapse of the cervix or uterus.

This is always a serious complication, especially if the uterus itself has prolapsed.  The prolapsed uterus is easily distinguished from the placenta as it is much more solid, is pink or red in colour, and is quite big, at least the size of a rugby ball but often big enough to fill a large bucket.

Speedy action is of the essence as damage to one of the big arteries (up to 2,5cm in diameter!) will lead to the death of the cow within minutes.  As the uterus hangs out, the veins are compressed which causes the organ to swell three times or more.  The larger the swollen mass, the more difficult it is to push it back into position.

As soon as a prolapse is seen the uterus should be cleaned with lukewarm salt solution and when clean, covered with a moist cloth or towel to prevent further soiling.  A vet should be called without delay as this requires professional expertise and a lot of patience.  In a small number of cases intestines inside the prolapse or tears in the uterus may further complicate matters.

Uterine tears.

Although the uterine wall is extremely tough excessive force may cause tears, especially if the wall has been weakened by infection or poor blood supply.  If tears occur while the calf is still inside the uterus a caesarian is often required.  If the calf has been freed it all depends where the tear has occurred — at the bottom of the uterus it is more dangerous since the uterine contents will leak into the abdomen, causing peritonitis.   If the tear is at the top of the uterus the chances of recovery are better because the weight of the uterus will tend to draw the edges of the wound together.   In both cases a vet should be called to assess the situation, but in some cases slaughter is inevitable.

Infection of the uterus.

Even if all care is taken to work as cleanly as possible, infection of the uterus after helping the cow calf is a strong possibility.   Therefore it is important to place pessaries and inject similar systemic antibiotics for a few days after the dystocia.   Infection may lead to infertility and in extreme cases to the death of the cow if black quarter-like organisms are involved.

Partial paralysis of the hindquarters.

On the inside of the pelvis are two thick nerves supplying the muscles on the inside of the thigh.   When a calf's hips get stuck for extended periods of time (30 minutes or more), these nerves are damaged and will the cow not be able to rise after calving.  Proper nursing is extremely important in these cases because the muscles of cattle are easily damaged if they are down for an extended lenght of time.   In severe cases it may take up to six weeks for an animal to get up, provided she is fed and cared for well and her muscles not damaged extensively.

Damage to the cervix.

If lubrication is inadequate or the tissues are handled roughly, tears to the cervix may lead to the formation of fibrous tissue in the cervix causing dystocia in later calvings.

Uterine adhesions.

In case of severe damage to the uterus adhesions may form between the uterus and the intestines, the rumen and even the inside of the pelvis.   These adhesions may lead to infertility and/or dystocia in subsequent calvings.

Bleeding from the uterus.

As mentioned above the two main arteries to the uterus are an inch in diameter.   If either of them are cut the cow could bleed to death in a matter of minutes.  

Do not hesitate to consult your vet — he/she is stil the best person to advise you on disease conditions in cattle!!

Acknowledgement for figures: Genesiology notes BVSc IV students, Faculty of Veterinary Science, University of Pretoria, South Africa.

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