Perioperative risk factors for puppies delivered by cesarean section in the United States and Canada

Abstract

The purpose of this study was to evaluate perioperative risk factors affecting neonatal survival after cesarean section. Data from 807 cesarean-derived litters (3,908 puppies) was submitted by 109 practices in the United States and Canada. Survival rates immediately, two hours, and seven days after delivery were 92% (n=3,127), 87% (n=2,951), and 80% (n=2,641), respectively, for puppies delivered by cesarean section (n=3,410) and were 86% (n=409), 83% (n=366), and 75% (n=283), respectively, for puppies born naturally (n=498). Maternal mortality rate was 1% (n=9). Of 776 surgeries, 453 (58%) were done on an emergency basis. The most common breed of dog was bulldog (n=138; 17%). The most common methods of inducing and maintaining anesthesia were administration of isoflurane for induction and maintenance (n=266; 34%) and administration of propofol for induction followed by administration of isoflurane for maintenance (n=237; 30%). A model of cesarean-derived puppies surviving to birth, between birth and two hours, and between two hours and seven days was designed to relate litter survival to perioperative factors. The following factors increased the likelihood of all puppies being alive: the surgery was not an emergency; the dam was not brachycephalic; there were four puppies or less in the litter; there were no naturally delivered or deformed puppies; all puppies breathed spontaneously at birth; at least one puppy vocalized spontaneously at birth; and neither methoxyflurane nor xylazine was used in the anesthetic protocol.

Hematocrit changes in healthy periparturient bitches that underwent elective cesarean section

“…Fluid therapy is recommended as a standard for CS in bitches [8][9][10][11][12][13][14]. Fluids are given to correct any fluid and electrolyte deficits, acid-base balances, the hypotensive effects of anaesthesia and maintain cardiac output and uterine blood flow [8].…”

Apgar score after induction of anesthesia for canine cesarean section with alfaxalone versus propofol

“…Anesthetic induction with propofol iv followed by isoflurane maintenance was reported to 64 result in improved puppy vigor and newborn survival rates compared to other general 65 anesthetic protocols and was considered almost equal to epidural anesthesia [6][7][8]. 66…”

“…Both maternal lethargy and 57 reduced neonatal vitality during the critical first postoperative hours result in reduced 58 colostrum intake and increased mortality rate of the puppies [3, [5][6][7]. Currently, many 59 veterinary clinics and practices use an anesthetic protocol with propofol induction followed 60 by isoflurane maintenance, with or without additional sedatives and / or analgesics.…”

“…Usually, anesthetic depth is increased after delivery of the last puppy, and supplementary 62 analgesics are administered [2, [6][7][8][9]. 63…”

Physiological events during parturition and possibilities for improving puppy survival: a review

“…Newborn puppy mortality for normal deliveries is 5.55%, significantly lower than that for dystocia deliveries, which is 33% (Moon et al, 2001). In cases of elective or emergency caesarean section, Moon et al (2000) reported neonatal death rates of between 6-11%.…”