Sunday, September 11, 2016

Caserean Section in Dogs and Cats: Surgical Technique

Indications

Cesarian section (C-section) in dogs and cats is indicated for a variety of reasons such as uterine inertia, oversized neonates, narrowed maternal pelvic canal, and others. Fetal dystocia is common in brachycephalic breeds such as Bulldogs, prompting some breeders or owners to schedule the C-section as an elective procedure in these kinds of dogs. Evidence fetal death or uterine infection would also warrant immediate C-section. The readers are referred to other publications for more information on dystocia in dogs and cats.(1)

Cesarian section is a safe surgical procedure and one study found fetal survival actually slightly higher with C-section than natural birth.(2) For information on pre-operative assessment and anesthesia for C-section see Veterinary Key Points blog by Dr. Lisa Ebner posted June 14, 2016.

Surgical Procedure

The abdomen is clipped and an initial scrub performed prior to beginning anesthesia. This minimizes the time spent under anesthesia helping to prevent depression of the puppies or kittens. Perform other pre-operative and anesthestic protocol as described in the Veterinary Key Points blog by Dr. Lisa Ebner posted June 14, 2016 on anesthesia for C-section.

Place the animal in dorsal recumbancy and perform a routine ventral abdominal midline approach. Be careful to avoid trauma to the enlarged uterus when entering the peritoneal cavity. Exteriorize the entire uterus including both uterine horns. (Fig. 1) This simple step is important to relieve pressure on the caudal vena cava by the very enlarged uterus and therefore improve venous return to the heart. Isolate the uterus from the peritoneal cavity with moistened abdominal sponges.
Fig. 1: Gravid uterus exteriorized from the abdominal cavity

Make an incision in the ventral aspect of the uterine body just proximal to the bifurcation of the horns.(3)  Take care to avoid trauma to the puppies inside the uterus. Once inside the uterine lumen, carefully begin removing puppies one by one.(Fig. 2)
Fig. 2: Begin removing puppies from the incision in the uterine body midline.
fromSicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006

Begin with puppies in the uterine body, then milk them down each horn to the incision and then remove. The uterine incision may have to be extended into the horns to reach and remove all puppies.

When each puppy is removed from the uterus, gently tear the placental membrane and remove it from the fetus.(Fig. 3) 
Fig. 3: After removing puppy from the uterus gently open and peel away placental membranes
from: Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006
Take care to avoid spillage of fluids into the peritoneal cavity. A convenient area to perforate the thin membrane is at the ventral neck of the puppy. Once the membrane has been removed, place 2 small hemostatic forceps on the umbilical cord, transect the cord between the clamps, and hand the puppy off to an assistant.(Fig.4a, b ) 
Fig. 4a: After removing placental membranes from the puppy, double clamp
the umbilical cord with small hemostats, cut between them, and pass the
puppy off to an assistant.


Fig. 4b: Double clamp umbilical cord and cut between the clamps.
from: Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006

The assistant will then ligate the cord with absorbable suture and begin routine care to stimulate respirations and assessment 
(see http://drstephenbirchard.blogspot.com/2016/06/anesthesia-for-cesarian-section-in-dogs.html).

Before uterine closure, be sure to check the entire uterus including the body and vagina for any remaining fetuses. Routine ovariohysterectomy can be performed now if requested by the owner. If the uterus is to be preserved, close the uterine incision with absorbable suture (Monocryl or PDS) in a Cushing pattern.  Lavage the abdomen with warm sterile saline if spillage of uterine contents has occurred into the peritoneal cavity. Close the abdominal incision routinely. Intradermal closure of the skin layer is preferred to avoid the irritation associated with skin sutures and nursing puppies.

Postoperative Care

When the bitch is fully recovered from anesthesia the puppies can be placed with her and encouraged to nurse. Carefully monitor the puppies and bitch to be sure she does not accidentally injure the pups. Soon after anesthetic recovery is it usually best to discharge the dog and her puppies back to the home and educate the owner on care of the bitch and puppies. See blog on C-section anesthesia for postoperative analgesia of the mother.

References

1. Graves T. Diseases of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006, pgs. 987-991.
2. Moon PF, Erb HN, Ludders JW, Gleed RD, Pascoe PJ Perioperative management and mortality rates of dogs undergoing cesarean section in the United States and Canada
JAVMA [1998, 213(3):365-369
3. Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006, pgs. 996-999.