Contributors: Zoe Halfacree, Lori Ludwig

 Species: Canine   |   Classification: Techniques

Introduction Requirements Preparation Procedure Aftercare Outcomes Further Reading

Introduction

  • Surgical management of dystocia Dystocia.

Uses

Maternal dystocia
  • Prolonged gestation.
  • Primary uterine inertia - inability of uterus to contract sufficiently (some breed predisposition, eg Boxer Boxer ).
  • Secondary uterine inertia, uterine muscles become exhausted after prolonged contraction (obstructing fetus, large litter, some breed predisposition, eg brachycephalics).
  • Unmanageable obstruction of birth canal, eg pelvic fracture.
  • Uterine anomaly, eg torsion, inguinal herniation of gravid uterus.
Fetal dystocia
  • Relative or absolute fetal oversize.
  • Irreduceable malpresentation.
  • Fetal death/putrefaction/mummification.
  • Signs of fetal distress in prolonged or difficult parturition.
  • Fetal deformity, eg fetal monster.
Elective Cesarean
  • History of previous dystocia.
  • Predictable dystocia associated with breed type especially brachycephalics.

Advantages

  • Increased chance of live pups following rapid removal of viable fetuses.

Disadvantages

  • Anesthetic depression of fetus.
  • Care required to prevent fetal hypoxia.
  • Cost.
  • Risk of surgical complications in dam (low).

Alternative Techniques

Medical management
  • Consider medical management prior to surgery if no obvious fetal anomalies or pelvic obstruction. (Oxytocin Oxytocin for non-obstructive dystocia with dilated cervix.)
  • Calcium gluconate Calcium gluconate for, eg primary uterine inertia due to subclinical hypoglycemia.
Manipulation
  • If reduceable malpresentations.
  • If marginal fetal oversize without uterine inertia.
  • If dead fetus obstructing canal.

Time Required

Preparation

  • Pre-operative blood tests to screen for hypoglycemia, hypocalcemia, anemia.
  • Supplementation with glucose and calcium as needed.
  • Clip hair 10 min prior to induction of anesthesia.

Procedure

  • 30-60 min.
  • Procedure should be performed as quickly as possible.

Decision Taking

Criteria for choosing test

General considerations
  • Objective evaluation of indications for surgical intervention not always possible.
  • Length of gestation shows great variation within normal (54-72 days).
  • Often difficult to assess cause of dystocia.
  • Considerable range in normal interval between expulsion of pups (5 min-2 h).
  • Digital examination of the vagina may detect a fetus lodged in the birth canal. Check for the presence of the Ferguson reflex (ie digital pressure on the ventral or dorsal vaginal wall results in abdominal straining). No reflex suggests that the dog is not in labor or that uterine inertia is present.
  • Decision often a subjective assessment of behavioral signs and experience.
Diagnosis of dystocia
  • Prolonged gestation greater than 65 days.
  • Persistent abdominal straining more than 30 min without expulsion of puppy.
  • Weak and infrequent abdominal straining which fail to produce puppy within 2-3 hours.
  • Absence of abdominal straining for longer than 4 hours between births.
  • Physical examination, eg pelvic obstruction.
  • Signs of systemic illness, eg toxemia, fever, depression, weakness.
  • Evidence of fetal death.
  • Abnormal vulval discharge.

Requirements

Personnel

Anesthetist expertise

  • Experienced anesthetist:
  • As many personnel as posible to manage neonates.

Materials Required

Minimum equipment

Ideal equipment

  • Sterile laparotomy swabs for packing of uterus.
  • Equilment for puppy resuscitation, eg suction, medications including adrenaline and doxapram Doxapram.
  • Incubator.
  • Towels/blankets for neonates.

Preparation

Dietary Preparation

  • Fast animal for 12 hours prior to anesthetic to prevent reflux esophagitis (if able - may need to be performed as an emergency.)

Site Preparation

  • Ventral midline approach: tilting bitch in dorsal recumbency relieves respiratory embarassment, alleviates caval occlusion, gives best access to gravid uterus.
  • Flank approach: avoids damage to mammary vessels and post-operative wound interference by young.

Standard Method

Other Preparation

  • Intravenous fluids if prolonged dystocia.

Procedure

Approach

Step 1 - Ventral midline laparotomy

Tilting bitch relieves respiratory embarassment and alleviates caval occlusion
  • Optional - in most animals (<30 kg) this is unnecessary.
  • Incise skin Cesarean 02 incise skin.
  • Make laparotomy exposure large enough only for uterine access Cesarean 03 laparotomy incision.

Core Procedure

Step 1 - Inspect and exteriorize uterus

  • Inspect uterus for signs of rupture or fetal death Cesarean 04 examine uterus.
  • May elect for ovariohysterectomy Ovariohysterectomy with client consent.
  • Carefully exteriorize.
    Sudden exteriorization may result in transient fall in blood pressure.
  • Pack off uterus from abdominal cavity with warm moist towels Cesarean 05 pack off uterus.

Step 2 - Incise uterus and removal of young

  • Make longitudinal incision at uterine bifurcation Cesarean 06 incise the uterus.
  • 'Milk out' pups through single incision Cesarean 07 remove the fetuses Cesarean section - removal of pups.
  • Perforate fetal membranes.
  • Clamp umbilicus before sectioning Cesarean 08 clamp umbilical cord.
  • Keep all pups warm and monitor carefully Cesarean 09 warm puppies Cesarean section - care of puppies.
    Ensure all pups removed, especially first dystocic pup.

Step 3 - Inspect placenta

  • Presence of placenta with pup often indicates fetal death.
  • Remove placenta if free; leave if still tightly attached.

Step 4 - Alternative technique - en bloc ovariohysterectomy

  • Exteriorize uterus.
  • Isolate ovarian pedicles and body of uterus.
  • Milk fetuses into uterine body.
  • Double or triple clamp pedicles and uterus cranial to cervix.
  • Transect between clamps and give uterus to team of assistants for resuscitation of fetuses.
  • Ligate pedicles of uterus and close.

Exit

Step 1 - Standard laparotomy closure

  • Same as laparotomy Laparotomy: midline Cesarean 12 close laparotomy wound.
    Cuticular or silk sutures may minimize pup-initiated wound complications.

Step 2 - Uterine closure

  • Suture (absorbable sutures) using inverting or appositional pattern Cesarean 10 repair uterine incision Cesarean 11 uterine repair.
    No real rationale for double layer of sutures.
  • Single and double layer closures have been recommended.

Aftercare

Immediate

Fluid requirements

  • Intravenous fluids if prolonged dystocia.

General Care

Neonatal care
  • Pass each puppy to assistant to be towel-dried.
  • Massage puppy to promote respiration. Doxapram Doxapram can be used to stimulate respiration 1-2 drops.
  • Suck fluids from fetal airways.
  • Maintain in warm dry environment, eg incubator. Naxolone Naloxone can be given to neonates to reverse narcotics given to bitch pre-operatively.
    Sucking may be delayed for up to 6 hours post-partum without detriment.
  • Return puppies to bitch on recovery.

Other medication

  • Oxytocin Oxytocin may help control hemorrhage.

Wound Protection

  • No wound protection required - use subcuticular sutures.

Potential complications

  • Hemorrhage, hypovolemia, hypotension, peritonitis Peritonitis if leakage of uterine fluids intra-operatively.

Outcomes

Complications

  • Diarrhea: not uncommon, hormonally-mediated or from eating placenta(e).

Prognosis

  • Good.

Reasons for Treatment Failure

  • Delay in procedure or prolonged procedure that results in death of viable fetus.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Metcalfe S, Hulands-Nave A, Bell M et al (2014) Multicentre, randomised clinical trial evaluating the efficacy and safety of alfaxalone administered to bitches for induction of anaesthesia prior to caesarean section. Aust Vet J 92 (9), 333-338 PubMed.
  • Smith F O (2012) Guide to emergency interception during parturition in the dog and cat. Vet Clin North Am Small Anim Pract 42 (3), 489-499 PubMed.
  • Evans K M & Adams V J (2010) Proportion of purebred dogs born by caesarean section. JSAP 51 (2), 113-118 PubMed.