In an average well looked-after herd, 9/10 of the cows
calving will not require veterinary attention. Dystocia (difficulty giving
birth) is most common in overfat heifers and cows, occurs in instances of careless
stockmanship but also occurs often just by chance.
This is an overview of the problems that occur around the
time of calving. For more detailed explanations and treatments for each
specific problem, use the following links…
·
Incomplete Cervical Dilation
·
Uterine Inertia
·
Uterine Torsion/Twister Uterus
·
Prolapses (Vaginal and Uterine)
Incomplete Cervical Dilation:
Incomplete cervical dilation occurs very occasionally in
heifers but the true incidence is difficult to determine because in most
situations, the onset of first stage
labour has not been noted. It is probable that some dystocia cases are
classified as incomplete cervical dilation but merely represent over-eager interference by inexperienced
stockmen.
Typically, when the cervix is not fully dilated, the opening
of the cervix is only 5-10cm in diameter which may just allow passage of one
hand.
Incomplete dilation of the cervix occurs at the start of the parturition process and will essentially hinder the following processes. In order for the foetus to leave the uterus and enter the birth canal, it must be able to pass through the cervix.
Treatment –
manual pressure applied for 10 – 15 minutes may gradually dilate the
cervix in some cases but such cases may well represent those that have been
eagerly and prematurely disturbed. In some cases the vulva may also fail to
dilate properly because there has been no pressure from the water bag and veterinary assistance is
necessary. Natural dilation is achieved by pressure
from an intact water bag being pressed through the cervix into the vagina
by contractions of the uterus. For this reason, it is unwise to manually rupture the water bag until full dilation is
complete.
Management/Prevention/Control
– too early/frequent human interference may delay normal
progression of first stage labour, especially in heifers. Farmers should be
encouraged to leave cattle undisturbed for 4
hours after the appearance of mucus string or allantochorion (first water
bag) at the vulva. However, frequent bouts of powerful abdominal contractions
occurring more frequently than every 5 minutes or so must be investigated.
Therefore, realistically speaking… if you notice that a
cow/heifer is starting to calve, ensure that she has privacy and comfort in a
calving shed with plenty of water and bedding. Allow her a period of 4 hours
before performing any kind of manually interfering check. If, after the time
given, you notice that the water bag has still not reached the vulva or noticed
any kind of rush of fluid, check that the cervix is dilated. If at this point
it is not sufficiently dilated, call for veterinary assistance.
For more
in-depth and practical information, take a look at my specific blog post on
incomplete cervical dilation *follow this link*
Oversized Calf
Dystocia caused by an oversized calf in normal anterior
longitudinal presentation is common in beef cattle. The calf’s muzzle and
forefeet are presented at the cow’s vulva.
Reasonable traction should deliver the calf when two people
pulling can extend both front legs such that the fetlock joints protrude one
hand’s breadth beyond the vulva within 10 minutes traction. If this happens,
this means that the calf’s shoulders have fit through the pelvis of the cow, no
further problems should be encountered. If after this effort, the calf is not
making progress further, veterinary assistance will be required.
If it is estimated that the calf will fit through the birth
canal in a safe manner without causing damage to the dam, then manually
delivery of the calf can be attempted.
Using lots of obstetrical lube inside the birth canal and on the equipment used can be very helpful. Pulling the calf in an ‘arc’ direction pathway when it exits the vulva is helpful too – this is because the calf naturally bends in this shape and so reduces damage and stress.
When pulling the calf out from the vulva, pull outwards and
downwards to get a good lateral movement on the calf and preventing damage.
Treatment –
judging the size of the calf against the birth canal will often lead to
the solution of having a caesarean to safely deliver the calf. Attempting to
force the calf through can lead to considerable damage to both the calf and the
dam. If forced extraction seems feasible, it should be undertaken in a
controlled manner.
Management/Prevention/Control
– in order to prevent this kind of dystocia, it is important to
implement strict feeding regimes and rations throughout the gestation period;
being most strict towards the end of gestation when the calf’s growth rate is
at its highest.
·
Review bull
selection especially in heifers, with references to EBVs – it is
inefficient to calve a heifer with a bull that is known to give huge calves,
which may lead to reproductive problems for future seasons of the heifer, as
well as risking the life of the calf during calving.
·
Do not
calve cows in body score conditions higher than 3 – as these
cows are at the most risk of having overfat calves.
Potential
problems -
·
Vaginal tear… tears in the vaginal wall during delivery of the calf may be sufficient to allow the protrusion of submucosal fat or extend to cause rupture of the uterine artery with life-threating consequences due to either infection of loss of blood.
Haemorrhage form a major artery in the vagina must be identified immediately after the calf has been delivered and veterinary attention sought urgently.
Essentially to avoid a vaginal tear don’t risk calving
a huge monster of a calf that quite clearly is too big for the cow’s birth
canal. The point at which the vagina tears is usually when the largest parts
(the head and shoulders) are passing through the vagina and more commonly, when
this happens too prematurely or too forcefully. Applying lots of lube to the
vagina area is a good way to prevent it from tearing.
When the head or shoulders are passing through the
vulva, putting lube on your hands are squeezing your hands between the head and
vagina, pulling the lips around the bulk of the mass, can ease the hardest part
of the delivery.
·
Hip lock… often
arises when excessive and inappropriate traction has been applied to an
oversized calf in anterior longitudinal presentation. The cow quickly becomes
exhausted with the calf protruding to the back of the rib cage but firmly
lodged as the hips enter the cow’s pelvis.
Treatment –
when the calf is in this position, it is important to realise that,
increasing the force of traction will usually make things worse. If the two
pelvic bones are locked together, no means of force will safely deliver the
calf. The best way to solve this problem is to first slightly repel the calf
back into the birth canal, by about a hands length. Try to rotate the calf into
a better position so that the pelvis of the calf is more likely to fit through
the pelvis of the cow; then try pulling again.
In the event that this does not work, simultaneously pulling
on the legs of the calf you rotate the calf can be helpful – almost ‘jigging’
the calf around so that it slips through the pelvis.
Another tip is to have one person place one foot on the
abdomen of the cow, at about where the calf’s pelvis should be, and press down
in rhythms as the calf is being pulled.
Attempting to stand the cow up can sometimes shift the
lodging of the calf.
Some stockmen attempt to roll the cow to dislodge the calf.
This comes with obvious hazards and should be avoided in most situations to
prevent any further damage to the cow or calf.
For more
in-depth and practical information, take a look at my specific blog post on
calves oversized *follow this link*
Abnormal Position of Calves
Normal position for a calf to be able to pass through the birth canal can be one of two ways. Anterior dorsal (calf facing forwards towards the exit passage, with both forelegs outstretched and the head nestled between the legs) or posterior dorsal (with the calf facing backwards, tail first out of the exit passage, with both hind legs stretched out along the birth canal). In order to correct an abnormal position, the calf must be rearranged into one of these positions.
·
Leg Back (Anterior longitudinal presentation with unilateral shoulder flexion) or (Anterior longitudinal presentation with unilateral carpal flexion)
…
Both of the positions described above are classed as ‘leg back’; the first, shoulder flexion means that the calf’s leg is bent backwards, from the shoulder. The second, carpal flexion, means the calf’s leg is bent in the middle of the leg, at the carpal joint (similar to the elbow in humans). This position is common in cattle obstetrics. The calf’s head and one fore foot are presented at the vulva.
In order to correct this malposture, an extradural injection is given by a veterinary surgeon to prevent forceful straining. After 5 minutes, the calf’s head and protruding foreleg are well lubricated and slowly repelled back into the birth canal until there is sufficient room to correct the position. By first grasping the calf’s forearm then the mid metacarpal region, the elbow and carpal joints of the retained leg are fully flexed which brings the foot towards the pelvic inlet. With the fetlock joint fully flexed and the foot cupped fully in the hand of the stockman (to protect the uterus), the foot is drawn forward into the pelvic canal extending the fetlock joints. Traction on the distal limb extends the elbow joint and the foot appears at the vulva where a calving rope can be applied to the fetlock joint.
After being delivered, the calf will need to have its umbilicus/navel fully immersed in strong veterinary iodine and repeated 2 and 4 hours later. Secondly, the tongue of the calf will probably be swollen and prevent the calf from suckling so two litres of colostrum should be given via orogastric tube.
To better understand how to correct this posture, watch this video demonstrating how to do so… http://www.nadis.org.uk/videos/leg_back.html
·
Head back (Anterior
longitudinal presentation with lateral deviation of the head)…
This presentation is a common problem; in most cases the calf is often already dead. Both fore feet are presented at the maternal pelvis (and possibly at the vulva if the legs are long enough).
The head back is often mistaken for a calf in posterior presentation (coming backwards) because you can feel two legs but not a head. If it were a posterior presentation, you would be able to feel the hocks on the legs being presented and the tail/tail head would be felt instead of a head.
This presentation is a common problem; in most cases the calf is often already dead. Both fore feet are presented at the maternal pelvis (and possibly at the vulva if the legs are long enough).
The head back is often mistaken for a calf in posterior presentation (coming backwards) because you can feel two legs but not a head. If it were a posterior presentation, you would be able to feel the hocks on the legs being presented and the tail/tail head would be felt instead of a head.
Correction of the malposture is not easy, especially when the calf is dead. Often, veterinary assistance is necessary. It is helpful if an extradural anaesthesia is given. The calf’s forelegs and neck are carefully pushed back inside the birth canal, until there is sufficient room for the calf’s head and neck to be turned forwards.
To turn the head to the correct position, the legs should be pushed backwards, then the calfs head rotated forwards; this may be made easier by using the calf’s mouth or eye sockets as grasping points. Alternatively, a leg rope can be placed in the mouth, around the lower jaw and then looped round the back of the head – pulling on the rope, provided there is enough room in the canal, should correct the head position. Once it has been corrected, the calf can be delivered as normal.
For help on how to correct this situation, see these videos on correcting this position: http://www.nadis.org.uk/videos/head_back.html and http://www.nadis.org.uk/videos/head_snare.html
·
Backwards
calf (Posterior longitudinal presentation)…
Although this is considered a normal and healthy way for a calf to be born, it can come with some serious complications.
The calf can sometimes suffer with multiple rib fractures, rupture of the liver and prolonged delivery resulting in compression of umbilical vessel causing lack of oxygen.
When calving a cow and the calf is backwards, do not put the calf under too much strain and ensure that the angle that the calf is being pulled at is not putting unwanted tension on the rib cage. When the legs are almost out it is important to realise that the umbilical cord will soon break and cause the calf to take its first breath, if the head is still inside the cow at this point, it is highly likely that the calf will start to suffocate.
Although this is considered a normal and healthy way for a calf to be born, it can come with some serious complications.
The calf can sometimes suffer with multiple rib fractures, rupture of the liver and prolonged delivery resulting in compression of umbilical vessel causing lack of oxygen.
When calving a cow and the calf is backwards, do not put the calf under too much strain and ensure that the angle that the calf is being pulled at is not putting unwanted tension on the rib cage. When the legs are almost out it is important to realise that the umbilical cord will soon break and cause the calf to take its first breath, if the head is still inside the cow at this point, it is highly likely that the calf will start to suffocate.
·
Breech
presentation (Posterior longitudinal presentation with bilateral hip
flexion)…
Essentially in this position, the calf’s rear end is lodged in the entrance to the maternal pelvis, with both of the hind legs bent forwards (towards the cows head) – if nothing is done to correct the posture of the calf, there is no way that the calf can be birthed naturally.
Cows show typical signs of first stage labour – but progression to second stage labour is rarely engaged due to the foetus not engaging with the maternal pelvis.
The water bag may rupture but remnants of the foetal membrane may not appear at the vulva. The calf’s tail is readily palpable on vaginal examination. In some cases, the problem is not noted until the calf has died and results in toxaemia of the cow.
Essentially in this position, the calf’s rear end is lodged in the entrance to the maternal pelvis, with both of the hind legs bent forwards (towards the cows head) – if nothing is done to correct the posture of the calf, there is no way that the calf can be birthed naturally.
Cows show typical signs of first stage labour – but progression to second stage labour is rarely engaged due to the foetus not engaging with the maternal pelvis.
The water bag may rupture but remnants of the foetal membrane may not appear at the vulva. The calf’s tail is readily palpable on vaginal examination. In some cases, the problem is not noted until the calf has died and results in toxaemia of the cow.
On the right, this is the breech presentation; on the left, this is what the calf’s posture needs to be changed to.
In order to do this an extradural injection is given to block the cow’s forceful abdominal contractions. The calf’s tail head is slowly pushed back beyond the level of the cow’s pelvic inlet as far reach allows. One calf’s foot is cupped in your hand and the first joint above the hoof fully flexed. As the hind foot is drawn toward the maternal pelvic inlet, the hock and stifle joints are fully flexed. Correction now involves extending each hip joint in turn while the joints on the lower leg remain flexed. (In essence, what this means practically is that, in order to make rotating the leg possible in the small space allowed, the lower part of the leg must be bent (joints flexed) while the top part of the leg rotates at the hip to extend the leg backwards; once the top part of the leg is extended, the lower leg joints can be extended in turn, starting at the highest joint). In this way, a breech presentation is converted to a normal posterior presentation.
To understand how to correct this presentation better, watch this video http://www.nadis.org.uk/videos/head_snare.html .
When attempting to correct any change to position of calf,
allow the cow to be standing; when trying to deliver the calf, the cow is best
in lateral recumbency (lying down on her side) so that the diameter of the
pelvis is at its maximum.
For more
in-depth and practical information, take a look at my specific blog post on
abnormal
calving positions *follow this link*
Immediately
after calving, examine the cow for…
Uterine
Tear/Rupture – this occurs during assisted delivery most commonly
with the calf presented in breech position, but also with lateral deviation of
the calf’s head.
If the condition is not recognised immediately the cow may appear to be normal for several hours after delivery. As peritonitis (infection of the peritoneal cavity) develops over several days, the abdomen becomes increasingly distended and contracts as the cow’s appetite reduces drastically.
Treatment of diffuse peritonitis involving the small intestine is invariably hopeless and the cow should be euthanised for welfare reasons.
If the condition is not recognised immediately the cow may appear to be normal for several hours after delivery. As peritonitis (infection of the peritoneal cavity) develops over several days, the abdomen becomes increasingly distended and contracts as the cow’s appetite reduces drastically.
Treatment of diffuse peritonitis involving the small intestine is invariably hopeless and the cow should be euthanised for welfare reasons.
Vaginal
Tear/Laceration – haemorrhage from a major uterine artery may result
from excessive traction in over-conditioned heifers and is apparent once the
pressure has been removed from delivery of the calf. Haemorrhage from a major
artery in the vagina must be identified immediately the calf has been delivered
and veterinary attention urgently requested.
Uterine
Torsion/Twisted Uterus – is relatively common and a major
cause of death in calves, due to failure of stock person to perceive the
problem.
This disease is often associated with an oversized foetus. Uterine torsion from 180* to 720* prevents entry of the foetus/fluids into the twisted vaginal lumen such that the animal shows no sign to indicate the end of first stage labour. Failure of the cervix to dilate is a common consequence.
This disease is often associated with an oversized foetus. Uterine torsion from 180* to 720* prevents entry of the foetus/fluids into the twisted vaginal lumen such that the animal shows no sign to indicate the end of first stage labour. Failure of the cervix to dilate is a common consequence.
The cow may isolate herself from the others in the group and
show signs of first stage labour including slackening of the SI ligaments, but
the foetal membranes (allantochorion) do not appear at the vulva. This is
because the exit to the womb and entrance to the pelvic inlet is blocked due to
a twist (or more than one twist) in the birth canal. The vulva and tail head are slack which
contrasts with the constricted vaginal wall lumen which is typically dry and
lacking in mucus. As you pass a hand into the vagina there is a distinct twist
(corkscrew effect) which can either be clockwise or anti-clockwise.
With a torsion less than 360* it may be possible to reach the cervix – if the calves legs can be held, the cow can be rolled in the opposite direction to the way in which the twist is; this may (hopefully) result in the twist unravelling and opening up the birth canal. In those cases where the torsion is more than 360*, or when the cervix cannot be reached, a caesarean operation is the best way of ensuring both the calf and dam survive undamaged.
With a torsion less than 360* it may be possible to reach the cervix – if the calves legs can be held, the cow can be rolled in the opposite direction to the way in which the twist is; this may (hopefully) result in the twist unravelling and opening up the birth canal. In those cases where the torsion is more than 360*, or when the cervix cannot be reached, a caesarean operation is the best way of ensuring both the calf and dam survive undamaged.
For more
in-depth and practical information, take a look at my specific blog post on uterine
torsion *follow this link*
If left unattended for a few days (with the thought that she is just ‘taking long to calve’) the cow becomes sick due to death of the calf, may develop toxaemia and most probably septic metritis.
Generally, the guidelines to follow with all calving situations are illustrated below…
0 comments:
Post a Comment