Chapter 48
Obstetrics: Cesarean Section
Cathleen Mochal-King
Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University,
Starkville, Mississippi, USA
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A cesarean section is a surgical procedure that is utilized to
relieve, or in some cases prevent, dystocia.1–3 Causes of dystocia are categorized as maternal or fetal and are covered in
Chapter 46. Indications for cesarean sections include dystocia cases in which the calves are alive and valuable that
cannot be delivered vaginally, and/or dystocia cases in
which the calf is dead but delivery by another means
jeopardizes the life or future fertility of the cow.
A cesarean section (C-section) is rarely completed under
strict asepsis, but this is not due to the fact that it is so often
performed in field settings. This is even the case when
a C-section is performed in a hospital setting in a surgery
room. A C-section is classified as a clean contaminated
procedure. This classification describes a surgery where
a nonsterile body cavity is entered under a controlled
condition without unusual contamination; in this case the
uterus is the nonsterile cavity.4 Furthermore, Mijten et al.4
demonstrated that uterine cultures collected during
C-sections often resulted in positive bacterial cultures,
with 83% of these samples heavily contaminated. This
leads to the conclusion that endogenous bacterial contamination of the surgical site from the hysterotomy is likely
inevitable.4 The fact that bacterial contamination is
probable does not excuse inattention to surgical preparation or to cleanliness. Therefore it is important to minimize
exogenous bacterial contamination through an efficient
and quick performance of the procedure. Additionally, my
recommendation is to administer antimicrobials preoperatively to diminish postoperative complications as a result
of the endogenous contamination.
Success of a C-section is defined as a live cow with a live
calf, and the ability to rebreed the cow. These outcomes are
dependent on a number of variables in addition to the surgeon’s skill. Many of these variables are beyond the surgeon’s control. A realistic approach to this surgery is to
evaluate the case, the surgical theater, the cow’s size, her
condition and attitude, the owner’s expectations, and the
prognosis. Then tailor your plan to the circumstances and
conditions presented. For example, there are several surgical approaches that have been described. It is typical for a
surgeon to identify more with one approach than another
due to preference and comfort level. However, there are
specific case presentations for which a particular approach
offers definite advantages. Newman5 discusses the importance of case selection when determining the surgical
approach. To aid a surgeon’s treatment plan, Newman categorizes the C-section procedure as elective, emergency nonemphysematous, and/or emergency emphysematous. This
categorization of the procedure is relative to the condition of
the calf and its effects on prognosis and case management.
The elective category allows the surgeon to choose to
some extent the time and the place that the surgery will be
performed as well as the ability to make other preparations.
Thus this category carries the best prognosis for success, the
exception being when the timing of the procedure might be
elective but is performed due to an infirmity of the dam
(fractured limb, etc.). The emergency obstetric case in which
a decision to proceed to C-section is made early in the
course of the dystocia without excessive manipulation and
particularly while the calf is still alive likewise carries a
very good prognosis. For both of these case categories only
basic postoperative management is required. The situation
in which the decision to proceed to C-section to deliver an
emphysematous calf should carry with it the expectation or
at least readiness for complications, significant postoperative care, and a guarded prognosis. Sometimes the decision
to proceed to C-section occurs after extensive obstetric
manipulation or even partial fetotomy efforts. This, in my
opinion, carries a less favorable prognosis than the emphysematous category.
MA
Introduction
Elective C-section
Indications for an elective C-section are a valuable fetus,
complicating factors such as a dam with a prepartum
vaginal prolapse, a small or malformed pelvis, a recent lifethreatening condition, and/or a prolonged gestation.1–3 In
any case, a history that includes breeding date or embryo
transfer date should help assess the expected calving date.
Calves born less than 2 weeks prematurely should not be
unduly at risk for complications or fatalities (see Chapter 44).
Bovine Reproduction, First Edition. Edited by Richard M. Hopper.
© 2015 John Wiley & Sons, Inc. Published 2015 by John Wiley & Sons, Inc.
Obstetrics: Cesarean Section425
Figure 48.1 Lifting newborn by rear limbs will duplicate aspects of
natural vaginal delivery. Do not shake or swing calf.
A C-section can be scheduled without respect to the initiation of parturition. Research performed comparing the timing of an elective C-section with respect to the stage of
parturition revealed that the presence of full cervical dilatation before performing the C-section allowed better postnatal respiratory and metabolic adaptation in full-term
calves.6 When comparing elective C-section with vaginal
delivery it is believed that aspects of vaginal delivery aid
calves in transitioning from the womb. Specifically, in a
study in which the hematologic profiles of calves delivered
by elective C-section were compared with those of calves
delivered by unassisted vaginal delivery, C-section calves
were uniformly more hypoxic and had a greater likelihood
of experiencing respiratory distress.7 Because of the experimental design, all the deliveries (both vaginal and C-section)
were uncomplicated. The hypoxia in the C-section calves
was not due to, or associated with, respiratory or metabolic
acidosis. The authors hypothesized that the unassisted vaginal delivery calves benefited from both the compression of
the fetal thorax that occurs during transit through the pelvis
and the temporary suspension by the hindlimbs improving
post-delivery oxygenation.7 Both of these events occur during spontaneous vaginal delivery.
To ameliorate these disadvantages, one option is to
administer dexamethasone (20 mg) with or without a prostaglandin to induce parturition (see Chapter 44). This of course
makes the C-section less “elective.” Certain techniques can
be performed on the neonate after delivery to improve
respiratory function. These are likely beneficial following
the delivery of any calf. Carefully lifting the newborn by
their rear legs, as illustrated in Figure 48.1, for a few seconds
should correspond with the stage of normal vaginal delivery
in which the calf is momentarily suspended. This must be
performed without swinging or shaking the calf, which
although a common practice can be injurious to the calf.
Following suspension, place the newborn in lateral recumbency. Grasp the thoracic limb, elevating and lowering the
limb. This limb motion lifts the calf’s chest off the ground
and facilitates thoracic excursions. Repeat this motion three
to four times. Additionally or alternatively respiratory
efforts can be stimulated by “tickling” the nasal openings of
the newborn with a straw or twig inducing a sneeze, further
aiding airway clearance (Figure 48.2).
Figure 48.2 Respiratory efforts can be stimulated by “tickling” the
nasal openings of the newborn with a straw or twig, inducing a
sneeze and further aiding airway clearance. Technique demonstrated here with an enteral feeding tube.
Emergency C-section
For prognostic reasons the decision to perform a C-section
must occur in a timely manner. Several clinical signs or circumstances can direct a quick decision to proceed to surgery. The first clinical assessment indicating a C-section is
the obviously small heifer with a small or abnormally
shaped pelvis.1–3 Next, as obstetric manipulations are made
and extraction of the calf is being attempted, pressure on the
proximal aspect of the fetal forelimbs by the pelvis resulting
in crossing of the forelimbs is an indication of fetal–maternal
pelvic size incompatibility. Additionally, failure to progress
in delivery of the calf is an indication for surgery. Clinicians
should have a preset metric (time frame) for progress during
obstetric procedures. For example, if obstetric manipulation
is being made with no progress for a period of 10 min, then
one must proceed to surgery. This is not to say that the calf
must be delivered in that or another designated time frame,
but that “progress” must be made.
In the case where the fetus is dead, and especially if it is
emphysematous, the prognosis is less favorable. Case
management and treatment plans must be discussed with
the owner with regard to outcome prior to proceeding.
Although a fetotomy is an option when the calf is dead,
certain clinical presentations favor C-section. C-section is
the treatment of choice for the emphysematous breech, the
unreducible uterine torsion, an undilated cervix, preexisting
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The Cow: Obstetrics and Reproductive Surgery
vaginal or cervical trauma from lay delivery attempts, and
uncooperative patient temperament.1–3,5 These cases, as
stated previously, dictate aggressive postoperative care and
an increased risk of complications
Surgical approaches
Surgeon preference, patient temperament, environment,
and case presentation dictate the surgical approach selected.
C-sections may be performed under standing sedation or
cast in recumbency. The surgical approach determines the
type of restraint employed and the method of anesthesia,
whether regional or general. Surgical approaches that have
been utilized for C-section are the flank (left or right), the
ventral midline, and the paramedian. There are no advantages for a paramedian over the ventral midline8 so that
approach is not covered here.
Standing left flank
The standing left flank approach is the most common surgical technique for C-section in cattle. The left flank approach
is superior in that the rumen prevents prolapse of intestinal
loops from the incision. This standing procedure is not recommended in animals that are likely to become recumbent
during the surgery due to exhaustion, hypocalcemia, obturator nerve paralysis, and/or highly fractious nature.2
Standing right flank
The standing right flank approach has limited indications. It
can be utilized when there is rumenal distension or adhesions on the left side from a previous left flank surgery.9 It
has also been advocated as the best approach for a C-section
performed due to hydrops allantois or hydrops amnii. In
these cases an attempt is made to remove the fetus and close
the uterus without the massive fluid loss that will result in
hypovolemic shock.8 The right flank incision may also be
utilized in the management of an uncorrected uterine
torsion. The surgical technique for a right flank C-section is
similar to a left flank approach, with the exception that on
entering the abdomen extra care must be taken to avoid lacerating small intestine as the rumen is not available to serve
as a shield.1–3 Additionally, it is recommended that the surgical incision does not extend too far ventrally so as to prevent small intestine from escaping the incision.
Ventral midline approach
The ventral midline is preferred by some clinicians as the
primary approach utilized for C-sections. This approach
has several advantages and additionally some specific indications even for those who favor a standing flank method.
The ventral midline approach is the preferred surgical
technique for removal of an emphysematous fetus.1–3 This
technique allows greater access to the uterus and minimizes
abdominal contamination during delivery. The ventral
midline also offers the benefits of closure of the linea alba,
allowing greater suture holding strength and less incisional
hemorrhage compared with the paramedian approach.
The greatest disadvantage of the ventral midline technique
is that it requires the cow to be cast in dorsal recumbency.
C-section for the treatment
of uterine torsion
A C-section must be performed to deliver the calf in cases
when a uterine torsion cannot be corrected by other
methods. Surgically assisted correction of the torsion via
a flank laparotomy followed by vaginal delivery of the
calf is preferred over a hysterotomy.8 However, Frazer
et al.10 demonstrated that one-third of all cases of uterine
torsion presenting to veterinary school referral hospitals
resulted in C-sections. Although either a standing flank
laparotomy or a ventral midline approach can be utilized,
the standing left flank approach will be described. The
incision for the flank laparotomy should be made about
25% longer than ordinarily done for a routine section.
Once in the abdomen an attempt is made to correct
the torsion. A second operator utilizing a de-torsion bar
transvaginally may assist this effort, but typically intra-
abdominal manipulation is all that is necessary. Following
reduction of the torsion, delivery of the calf is dependent
on several factors. Fetal viability, uterine health, and
cervical dilation dictate the manner of the delivery. If
cervical dilation is sufficient, a vaginal delivery may be
made at this time and the flank laparotomy closed. If
dilation is not adequate or calf viability is questionable,
proceed with a hysterotomy.
In the situation where the torsion cannot be corrected or
the uterus ruptures during manipulation, realize that access
to the hysterotomy and/or the uterine tear will become difficult as the uterus returns to its normal position. At this
time I recommend a second approach from the right flank to
assist in the closure of the hysterotomy and/or management
of the tear. In both of these scenarios, either the torsion that
cannot not be corrected or the uterine rupture, the fetus is
likely dead and the uterus has already undergone extensive
damage. Thus case management reflects heroic measures
that carry a guarded prognosis. However, considering the
value of some animals and the expectations of the modern
owner, practicality is often dismissed.
Restraint and anesthesia
Flank laparotomies can be performed with the patient
standing or in right lateral recumbency. Restraint when performed standing can range from haltered and tethered to
the almost complete immobility provided by a cattle squeeze
chute. In fact some cattle chutes with adjustable side panels
can be set so narrow at the floor level as to prevent a cow
from lying down.
An anesthetic technique described by Abrahamsen11 that
provides analgesia and enhances patient cooperation while
maintaining recumbency is the “Ketamine stun,” which
involves the administration of ketamine in combination with
butorphanol and xylazine. Specifically, it can be administered intramuscularly at the following doses: butorphanol
0.01 mg/kg, xylazine 0.02 mg/kg, and ketamine 0.04 mg/kg.
This will provide duration of effect for 45 min. Abrahamsen
also reported a simplified protocol utilized originally by
Dr David Anderson while at Kansas State, referred to simply
as the “5–10–20” technique. This refers to an approximate dose
calculated for a 500-kg cow, but reported to be safe in cattle
weighing 340–660 kg. The combination dose is 5 mg butorphanol, 10 mg xylazine, and 20 mg ketamine administered intramuscularly to the patient.11 The timing to onset of the clinical
effect for this combination when administered prior to clipping and preparing the surgical site is typically perfect.
Regional anesthesia options are the proximal paravertebral
block or the inverted L block, both described in Chapter 15.
Surgical technique
The surgical site should be clipped and thoroughly scrubbed
with chlorhexidine. I recommend using cloth or paper
drapes to cover the chute to reduce contamination of the
exposed uterus (Figure 48.3).
Standing flank approach
A vertical skin incision is made in the middle of the paralumbar fossa beginning 10 cm ventral to the transverse
vertebral processes extending distally for a distance of
25 cm.1–3 The incision is extended to a length sufficient to
allow extraction of the calf. Alternatively, an oblique celiotomy incision can be made.12 This skin incision is begun
8–10 cm cranial and 8–10 cm ventral to the cranial aspect of
the tuber coxae and extended cranioventrally at a 45° angle,
ending 3 cm caudal to the last rib. The oblique approach
allows for better access to the gravid uterus.
Incision of the skin and the subcutaneous tissue exposes
the fibers of the external abdominal oblique muscle. This
muscle is incised vertically the entire length of the skin incision. Next the internal abdominal oblique muscle is incised
in a similar fashion. On completion of this incision the aponeurosis of the transverse abdominal muscle is revealed.
Care must be taken in this step to prevent inadvertent
entrance into the rumen. To avoid perforating the rumen tent
the transverse abdominal muscle with tissue forceps to make
a small incision through the muscle and the peritoneum with
a scalpel blade or Metzenbaum scissors. Once a small opening is made, elongate the incision using the tissue forceps as
a tissue guard. Incise the remaining transverse abdominal
muscle and the peritoneum with the blade or the Metzenbaum
scissors. When the peritoneum is incised and the abdominal
Figure 48.3 Surgical pack.
Obstetrics: Cesarean Section427
cavity opened, the sound of air entering the potential space is
heard. The rumen is identified and pushed cranially to allow
access to the uterus (Figure 48.4). In the case of a fetus in a
normal anterior position, a hindlimb within the gravid horn
will be both the most recognizable and accessible part of the
calf. The distal hindlimb is used as a handle to exteriorize the
uterus through the abdominal incision (Figure 48.5). When
the part of the uterus that encases the distal limb is exteriorized, the hock is then identified and “hooked” outside the
incision. The uterus is incised along the greater curvature,
but care must be taken to incise only the gravid horn and
avoid the uterine body. The incision begins over the hock and
extends to the claw. Care must be taken to avoid incising
placentomes and the fetus itself. Be forewarned that incisions
that are too short will result in tearing of the uterine wall
as the calf is delivered. These tears are always ragged and
somewhat perpendicular to the incision line, complicating
subsequent closure. After the incision is made, obstetric
chains can be attached to facilitate delivery. Following
delivery of the calf, the uterus is examined for the presence of
another fetus, uterine trauma, and tears of the uterine wall.
Uterine closure
The placenta is not removed unless it is easily detached.
Care must be taken not to include the placenta in the uterine
closure. Often it is helpful to trim away some of the membranes
from the incision prior to closure to prevent incorporating
Figure 48.4 The rumen is identified and pushed cranially to allow
access to the uterus.
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The Cow: Obstetrics and Reproductive Surgery
(a)
(b)
Figure 48.5 In the case of a fetus in a normal anterior position, a
hindlimb within the gravid horn will be both the most recognizable
and accessible part of the calf. The distal hindlimb is used as a
handle to exteriorize the uterus through the abdominal incision.
Figure 48.6 Initiating the Utrecht suture pattern: begin the suture
line proximal to the uterine incision and do not enter the lumen of
the uterus.
it into the suture line. The uterus is then closed with an
inverting continuous suture pattern. The Cushing pattern
or a modified Cushing pattern, the Utrecht uterine suture,
is recommended (Figures 48.6, 48.7, 48.8, 48.9 and 48.10).
The advantage of the Utrecht pattern is reduced postoperative adhesions because the suture and knots are buried.3 A
tapered needle and chromic or plain catgut suture (#2 or #3)
is recommended as at least one study comparing plain
Figure 48.7 Once the knot is secure, place each bite at a 45° angle
oblique to the incision proximal to the exit of the previous bite.
Figure 48.8 Tighten the incision line by pushing the uterus away
from the suture line, so giving the closure a bunched or pursed
appearance.
catgut to polyglactin 910 revealed no significant advantage
to the use of the synthetic product.13 A single layer closure
utilizing the Utrecht pattern is adequate unless there is concern with regard to the competency of the first suture line
or the condition of the uterus. In cases of severely contaminated
fluids a two-layer closure is indicated. A simple continuous
Obstetrics: Cesarean Section429
Figure 48.9 Complete the Utrecht suture line to bury the knot.
Figure 48.10 Note that as the Utrecht knot is tightened, the remaining
suture is covered.
followed by a Cushing pattern improves the competency of
the closure in a contaminated environment. Regardless of
closure it is important not to delay suturing as the uterus
begins to involute quickly.3
Once closure of the uterus is complete, removal of blood
clots and contamination from the serosal surface is imperative in reducing postoperative adhesions (Figure 48.11).
Following closure of the uterus the administration of 10–20
IU of oxytocin into the uterine wall and 30–40 IU intravenously will hasten uterine involution and aid in passage of
the placenta (Figure 48.12).
Then depending on the level of abdominal contamination
it may be advisable to lavage the abdomen with large volumes of saline to remove clotted blood and debris. If there is
gross severe contamination, large volumes can be used and
egress of lavage fluids can be facilitated by placement of a
rumen trocar through the ventral abdomen as described in
Chapter 53. In addition to lavage, carboxymethylcellulose,
heparin, potassium penicillin, flunixin meglumine, glycerol,
and tetracycline have all been advocated as components of
postsurgical abdominal lavage.5,14–16
When the exteriorized portion of the uterus has been
maintained outside the abdomen for the delivery and uterine
closure, it can be assumed that there is no abdominal contamination. Contamination must be assumed in cases such as an
unresolved uterine torsion, a fetus in the “breech” posterior
Figure 48.11 The accumulation of blood clots along the incision
incite the formation of adhesions that reduce fertility. Note how the
uterus is withdrawn into the incision. A surgeon must work quickly
due to the rapid involution of the uterus.
Figure 48.12 Following completion of the uterine closure and
lavage of the serosal surface, the administration of 10–20 IU oxytocin into the uterine wall and 30–40 IU i.v. will hasten uterine involution and aid in passage of the placenta.
presentation, or large fetal size preventing the complete exteriorization of the uterus.1 This raises a couple of issues. First,
a cautionary note with respect to the use of a popular obstetric
lubricant, J-Lube, which has been shown to be fatal to cattle,
horses, and mice following intra-abdominal exposure.14 Thus
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The Cow: Obstetrics and Reproductive Surgery
because the avoidance of abdominal contamination by the
uterine contents is almost impossible, it is recommended to
avoid the use of J-Lube in obstetric cases that ultimately
result in C-section. Conversely, sodium carboxymethylcellulose, which is a very good obstetric lubricant, is not only safe
but has been used in abdominal lavage fluids to minimize
adhesions.15
Body wall closure
Abdominal wall closure is achieved in three layers. The peritoneum and the transverse abdominal muscle are closed
together with simple continuous suture pattern using #2 or #3
chromic catgut or synthetic #3 polyglactin 910. The internal
and external abdominal oblique muscles as well as the subcutaneous fascia are closed with a simple continuous using #3
polyglactin 910. I recommend closure beginning distally and
working proximally to help contain viscera within the abdominal cavity. Skin closure can be performed with 0.6-mm nylon
(Braunamid™) utilizing a pattern of the surgeon’s choice.1–3
Ventral midline approach
The cow is cast in dorsal recumbency with both the head
and the forelimbs tied in extension. The abdomen is clipped
and aseptically prepared. A midline incision is initiated
immediately cranial to the udder extending cranially 5–7 cm
beyond the umbilicus.2 Once the skin and subcutaneous tissues are incised, a small stab incision is made through the
linea alba. This stab incision is large enough to pass a finger
or forceps to elevate the body wall to allow extension of the
incision along the linea while minimizing risk of abdominal
visceral penetration. Once the abdomen is entered, downward pressure on the body wall will help to push the gravid
horn of the uterus toward the incision. Manipulation of the
uterus, delivery of the calf, and closure of the uterus are as
previously described.
Closure of the linea alba and peritoneum is obtained by
using either a simple continuous or near-far-far-near pattern
with #3 polyglactin 910. To facilitate closure, placement of
towel clamps along the incision or several interrupted cruciate sutures will help alleviate tension as the incision is
closed. The subcutaneous tissues are apposed with absorbable suture in a simple continuous suture pattern. The skin
should be closed with 0.6-mm nylon (Braunamid) in a
simple interrupted cruciate pattern; continuous patterns are
difficult to remove from a ventral midline incision.
Postoperative management
and complications
Complications following C-section include endotoxemia,
peritonitis, metritis, adhesions, and reduced fertility.1–3,5
Mostly these complications are the result of bacterial contamination. As previously stated, all C-sections should be
considered clean-contaminated surgeries even in the best of
circumstances. Therefore, broad-spectrum antibiotics and
nonsteroidal anti-inflammatory agents should be administered prior to surgery. Systemic antibiotics should be maintained for 3–5 days following surgery depending on the
degree of surgical contamination. Severely endotoxic animals
by definition should be treated with antimicrobials several
days beyond the resolution of the endotoxemia. Endotoxic
animals will require additional cardiovascular support of
intravenous fluid therapy. Clinical signs of peritonitis,
pyrexia, inappetence, and ileus usually become apparent by
3 days after surgery. In the absence of these clinical signs
antibiotics may be discontinued.
Intra-abdominal adhesions can reduce future fertility.
The chapter has previously stated that utilizing the Utrecht
suture pattern and removing blood clots from the uterine
serosa will remarkably reduce postoperative adhesions. I
recommend using 1 L of carboxymethylcelluose prior to
body wall closure to further decrease the risk of postoperative adhesions. Postoperative fertility is reduced approximately 15% from fertility rates in cows that did not have
C-sections. Furthermore, postoperatively pregnancy rates
can be expected to be between 60 and 80%.1,2
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