Introduction

Every small animal practitioner should be comfortable with management of canine Cesarean sections (C-sections). The procedure will often be required on an emergency basis and requires immediate attention. The urgency of the procedure in many cases requires quick thinking; tailoring your procedure and protocols for both doctors and support staff can help maximize smooth recovery of the puppies as well as best possible recovery of the dam and acceptance of her new role as a mother.

Anesthetic Options

All choices for medications should be carefully examined for safety relating to pregnancy and lactation. The most common choices for induction currently in use are propofol and alfaxalone, and both of these agents also can be used for maintenance until fetal delivery is complete.¹ After the delivery is complete, conversion to an inhalant anesthetic can be elected.

Pre-oxygenation appears optimal for both the dam and puppies. Intravenous fluids are advised for all C-section patients, who are commonly hypotensive. Epidural anesthesia may reduce the requirements for injectable and inhalant options but should only be performed if a skilled technician can place it quickly. Speed from induction to delivery should be optimized, and any non-essential tasks should be performed ahead of time or aborted if problematic.

Surgery

The patient should be placed in dorsal recumbency and abdomen should be clipped and scrubbed for surgical entry. In the case of pregnant animals, tilting the dog slightly off position can benefit the animal’s ventilation as well as vascular return. The animal can then be “straightened” immediately prior to draping by the technical staff. Line block using local anesthetic agents (i.e., lidocaine 2%) may be performed on the midline in the area of anticipated incision. Using line blocks may lessen the overall need for anesthesia.¹

The surgeon should be aware of the vascularity of the mammary glands, as often large vessels will cross midline and can be a significant source of hemorrhage. Initially, quick ligation or hemostats should be used for control, in order to enter the abdomen as efficiently as possible for fetal delivery. Care should be taken to enter the abdomen very carefully; the abdomen is under pressure, and uterus and its enlarged vasculature are often pressed toward the linea.

When possible, the uterus should be elevated in its entirety. The loops of uterine horns may be convoluted and confusing in orientation, and it is important to confirm that no structures are twisted once resting on the exterior. Vascularity is impressive in the gravid uterus, so great care and a gentle hand should be used during manipulation. Using a blade, incision may be made in the least vascular area over the uterine body or base of a uterine horn. In most cases, puppies can be milked from either horn through a single incision. Care should be taken to place laparotomy sponges or gauze to prevent uterine contents from entering the abdominal cavity.²

Fetuses should be extracted as quickly as possible. Fetal sacs may be ruptured by the surgeon or handed off with the fetus as a unit. Placentas should be removed with gentle traction if possible. Microdoses of oxytocin may be used to reduce hemorrhage associated with the uterus and maternal placentas, though it can cause uterine contraction and alter the ease of closure. Closure can be performed via appositional or inverting patterns,² with two-layer closure having been the preference of most practitioners. One-layer closure has in recent years shown to be an effective option as well. If oxytocin has not already been implemented, it may be given after incision completion to help further bury the incision and reduce the uterine size.

Thorough examination of the tract should be performed before replacement into the abdomen, to ensure all fetuses have been delivered, and no pathology exists. Resorptive lesions noted in mid-pregnancy are often observable at surgery, both visually and by palpation. These lesions will often be associated with a mucoid whitish yellow colored discharge within the uterus. If observed, culture of this discharge is indicated, to rule out presence of infectious causes of resorption of early pregnancy.

Lavage of the abdomen (if needed) and routine abdominal closure can follow. All types of closure are acceptable, including internal or external suture patterns, and staples. Although it seems puppy interaction would cause tangling in external suture, this is not typically observed. Cleaning with a wet cloth of all of the mammary glands post operatively will help to remove the taste of the sterilizing agent used during preparation for surgery; this practice will improve nursing post-operatively. As soon as the dam is in recovery, monitored nursing efforts should commence.

Arguments for Concurrent Ovariohysterectomy

Many circumstances can present in which removal of the ovaries and uterus may be indicated at the time of C-section. Uterine disease, uterine rupture or tear, or presence of fetal autolysis can be appropriate situations to perform concurrent ovariohysterectomy. When the uterine health is optimal, some practitioners will still advise spay for bitches without plans for remaining intact for future breeding. While in many cases this is elected by owners, it should be cautioned given the risks relating to post-operative complications. Removal of a massive and vascular organ can create shock in the post-operative period, as well as put the patient at higher risk for post-operative bleeding, and thromboembolism.

Neonatal Resuscitation

Prior to delivery of the puppies, a resuscitation station should be created. A shallow wet sink, towels, and heat sources can be used as a makeshift station in most hospitals. Items that should be readily available include suction bulbs, small hand towels (at least two per puppy anticipated), 25-g needles or acupuncture needles, umbilical disinfectant, stethoscope, and suture material.³ Hand towels should be kept warm prior to use, and providing new warm towels during resuscitation can make recovery of puppies progress much more smoothly than previously observed. Emergency drugs, such as epinephrine, and 22-g catheters should be available for intraosseous catheter placement.

Handing off puppies can be stressful for the surgeon and the assistant, relating to protecting sterile field. The design of the surgical area will lend itself to certain methods, but in some hospitals, it may be possible to lightly lay the puppies onto a sterile towel.

Although “swinging” puppies via centrifugal force was formerly adopted by some clinics, this practice has since been discontinued due to documented cases of cerebral hemorrhage and death relating to the force applied.⁴

Post-operative Recovery

It is critical to monitor the bitch at all times during recovery when puppies are nursing or interacting. Bitches may be reluctant to accept puppies, become aggressive or cannibalistic, or crush puppies unknowingly.⁵ Owners should be advised to manage bitches with constant supervision for at least 48 hours post operatively, even if maternal behaviors have developed. Dog appeasing pheromone (DAP) products can be used to help foster optimal maternal behaviors. In extreme cases, oxytocin delivered via intranasal spray can help to improve maternal behaviors in the event of poor litter acceptance.

Long-Term Considerations

In general, the procedure does not cause a decrease in fertility on future cycles in the dog, if management of the bitch is optimized in surgery and post operatively. If a significant dystocia occurred, perhaps with autolyzed fetuses, fertility may be impacted. Abdominal adhesions may form on some individuals relating to the uterine incision, but anecdotally, aren’t associated with future infertility, and are often found at the time of C-section in breeds who have elective C-sections.

Although often advised against in human medicine, C-sections can be performed on an elective or emergency basis in dogs and subsequently be followed by natural whelping on later pregnancies.⁶ If the C-section involved a dystocia, close examination of the causes of the need for C-section should follow, and may indicate need for repeated C-section on any subsequent pregnancies. The offspring of bitches requiring C-section may also need to be monitored for similar trends, as familial concerns may warrant adjustment of the breeding program’s selection criteria.

References

1.  Pascoe PF, Moon PJ. Periparturient and Neonatal Anesthesia. Clinical Theriogenology. 2001 Mar;31(2):315–341.

2.  Fossum TW. Small Animal Surgery. 3rd ed. St Louis, MO: Mosby Elsevier; 2007:418–420.

3.  Lopate CL, ed. Management of Pregnant and Neonatal Dogs, Cats, and Exotic Pets. Ames, IA: Wiley-Blackwell; 2012:77–92.

4.  Grundy SA, Liu SM, Davidson AD. Intracranial trauma in a dog due to being “swung” at birth. Top Companion Anim Med. 2009;24(2):100–103.

5.  Jackson PG. Handbook of Veterinary Obstetrics. 2nd ed. St. Louis, MO: Saunders; 2004:193–198.

6.  Johnston SD, Root MV, Olson PNS. Canine and Feline Theriogenology. Philadelphia, PA: W.B. Saunders Company; 2001.