Neonatal Resuscitation Of Puppies Following Caesarian Section Stephanie Todd, DVM  Harmony Veterinary Clinic

Summary:

Neonatal mortality rates are highest from zero to three days of age. About half of the survivors are stillborn, 20 percent have anatomic abnormalities, nine percent are cannibalized, and most of the rest are lost due to trauma or infectious disease (Dr. Cheri A. Johnson, The North American Veterinary Conference 1995). Low birth weight is an important risk factor for early losses. Difficult labor and caesarian section add significant risk. Our goal is to minimize loss of puppies by aggressively resuscitating them from the effects of anesthesia, fluid-filled respiratory tracts, and in some cases the stress of prolonged labor. Puppies should be warm, well-hydrated, have normal blood glucose levels, and be crying and ready to nurse as soon as possible after delivery.

Normal vital signs for neonates are: body temperature 94-96' F, irregular respiratory rhythm/ breathe with no pause between inspiration and expiration, heart rate 200-240 beats per minute, bright red gums, hematocrit equal to dam's, TP = 5-6, BUN = 7-10, glucose = 40-60. Neurologic reflexes include: suckle, rooting (cup hand around muzzle and should push), lumbar rubbing causes squeal, toe massage causes head wobble, extended neck causes flexion of all four limbs from days zero to four (flexor dominance) and extension of all four limbs from days five to 21. Depressed or absent neurologic reflexes may indicate hypothermia, low blood glucose, or a central nervous system (CNS) disorder.

Resuscitation of neonates follows the 'ABC' acronym used for resuscitation in adults (A airway, B = breathing, C = circulation). The complicating factor with neonates is that the lungs are collapsed and full of fluid. Surfactant, the substance that coats the alveoli of the lungs and allows them to expand properly, may be present in decreased amounts in pups that are premature. Difficult delivery can lead to decreased blood oxygen levels in the puppies by loss of placental blood flow, early placental separation, or early rupture of the umbilicus. Anesthetics given to the dam can cause respiratory, cardiac, or CNS depression in the puppies, necessitating physical and pharmaceutical stimulation to aid in recovery. Planned caesarian sections often result in vigorous puppies that have no need for intensive care. Emergency caesarian sections, however, especially those following prolonged labor, may result in depressed puppies that will not survive without aggressive resuscitation techniques.

The following steps comprise our protocol for neonatal resuscitation: 1) Airway

Stimulate breathing (imitate mother) by clearing airway of membranes and vigorously rubbing puppy

-Suction airway with a bulb syringe

-Swing puppy downward with head low to clear lungs (does not seem to cause bleeding around the brain as it would in a human infant)

2) Breathing

-If no breathing in 30-60 seconds, administer oxygen; inflate lungs first by blowing in mouth/nose. Oxygen may be given by facemask, oxygen chamber, or core warming (described below).

-If still no gasping/breathing, then give Dopram under tongue or in umbilical vein (works for 15-20 minutes). Don't give more than two doses, as the benzyl alcohol component can cause CNS toxicity and hyperventilation can lead to acid-base imbalance.

3) Circulation

-Rewarming with oxygen-rich, moist warm air is ideal. This prevents overheating and bums from other external heat sources, and raises the core body temperature quickly (core warming). This immediately improves cardiac performance and increases circulation to vital organs. The technique is accomplished by placing puppies on a grate over hot (steaming) water underneath an oxygen tent.

-Correct dehydration and hypoglycemia by giving warmed fluids intraperitoneally (Lactated Ringer's solution /LRS with 2.5 percent dextrose @I ml/30gm), or via an intraosseous catheter (10 percent dextrose @ 0. 1 ml/3 0gm, and LRS @ 1 ml/3 0gm initial bolus).

Neonates cannot regulate their body temperature, cannot constrict small blood vessels to preserve blood flow to vital organs, and cannot increase the strength of heart muscle contraction Oust the heart rate). In order to maintain circulation in these puppies, we must always aim to correct hypothermia, hypoglycemia, and dehydration.

Poor prognostic signs for neonatal survival include prematurity (indicated by sparse hair coat, especially on the top of the paws), a heart rate of less than 80 beats per minute, and lack of gasping/breathing despite following the above protocol. Do not give up on any puppy, however, without doing a 'drop test' to check for total loss of reflexes. Drop the

puppy, abdomen downward, from a six-inch height onto a firm surface, and watch for the limbs to spread out and pull back in a quick,, subtle movement. Some puppies with no detectable heartbeat but a positive "drop test" have been revived after fifteen to 30 minutes of stimulation and core warming.

Core warming and intermittent, vigorous stimulation should be continued until pups are breathing, hydrated with fluids and dextrose, and moving when stimulated. They can be moved to an oxygen chamber for further supportive care if needed. Neonates are ready to be removed from oxygen and placed with the dam (or in a heated whelping box) when they are moving and crying, have heart rates over 200 beats per minute, and have normal neurologic reflexes.

Biographical Profile

Stephanie Todd received her DVM degree from Cornell University in 1987. She developed an interest in canine reproduction and has pursued it in private practice over the last twelve years. She currently owns Harmony Veterinary Clinic in Ballston Spa, New York. Her licensed veterinary technician, Debbie Johnson, is an integral part of the obstetrical and neonatal medicine and surgery performed at the practice. The protocol used at Harmony Veterinary Clinic for neonatal resuscitation following caesarian sections is a combination of standard techniques recommended by reproductive specialists and some innovative techniques, which are the subject of this presentation.

Dr. Robert V. Hutchison, who earned his DVM from The Ohio State University, is currently a co-director of the Animal Clinic Northview, Inc., an American Animal Hospital Association certified, ten doctor veterinary practice. Recognized internationally for work with canine frozen semen and canine reproduction, Dr. Hutchison produces approximately 150 frozen semen litters yearly.

Dr. Hutchison is the Director of the International Canine Semen Bank of Ohio, and a member of the American Veterinary Medical Association, the American Animal Hospital Association, the Society for Theriogenology and the Ohio Veterinary Medical Association. He has served on the Continuing Education Committee, the Ethics & Grievance Committee, the Program Committee, and the Racing Committee of the OVMA, as well as being a leader of the Lorain County Veterinary Medical Association and the Canine and Feline Fertility and Sterility Group.

He currently serves as on off-quarter advisor for College of Veterinary Medicine students interested in small animal theriogenology from The Ohio State University, Virginia Tech, Purdue University, Tufts University, Michigan State University and Auburn University. In addition, Dr. Hutchison has authored articles on canine reproduction in various breed journals and magazines, made television appearances and been featured in such publications as Canine Chronicle and AKC Gazette.

An internationally recognized speaker on canine and feline infertility, reproduction, whelping and pediatrics, Dr. Hutchison also finds time to serve on the Board of Directors of the Samoyed Health and Research Foundation, study the fertility proteins in canine semen with a grant from the AKC Endowment Fund and work as a consultant for Veterinary Forum and the Veterinary Information Network.

Deborah Johnson, is a licensed veterinary technician who graduated Suni Delhi in 1992. She is currently the head technician at Harmony Veterinary Clinic where she has worked since 1992. Ms. Johnson breeds and shows Vizslas and is interested in reproductive work and canine behavior.