When puppies and kittens are born, they do not normally require assistance or resuscitation to survive. However, when neonates
are stressed during parturition and the periparturient period, morbidity and mortality increase. Timely, effective intervention
is required to successfully resuscitate a stressed neonate.
Puppy and kitten mortality rates vary from 9-26%. Neonates that fail to survive to weaning are most commonly stillborn or
die within the first three days of life. Factors implicated in perinatal deaths include prematurity, in utero infection,
anatomic birth defects, birth trauma/dystocia, low birth weight, inadequate nutrition, maternal neglect, and environmental
stresses. Neonatal survival is optimized when breeders have good husbandry practices. Prospective planning includes genetic
screening of the prospective dam and sire, ensuring that that dam is healthy at the time of breeding and throughout gestation,
managing labor and delivery to reduce stillbirths, controlling parasitism and reducing infectious disease, preventing injury
and environmental exposure, and optimizing nutrition of the dam and neonates.
The veterinarian should adopt a pro-active attitude and become involved long before presentation of a critical neonate. Client
education in the prebreeding, breeding, prenatal, parturient and postpartum periods can increase neonatal survival, first
by facilitating breeders to control or eliminate factors contributing to puppy and kitten morbidity and mortality and second
empowering breeders with early warning signs so that veterinary intervention, should it become necessary, is timely.
Veterinarians often need to treat stressed and depressed neonates following dystocia and Caesarian section of the dam. In
this situation, the primary causes of fetal depression are hypoxia and anesthesia.
Neonates do not respond to hypoxia in the same manner as adults. In contrast to adults, hypoxic neonates respond with a decrease
in heart and respiratory rates, presumably as a protective response to low pO2. This compensatory response allows the neonate to survive a longer exposure to hypoxia than would an adult.
Baroreceptor reflexes are not present, nor is sympathetic innervation of the heart complete during the first 4 days of life.
So bradycardia in the neonatal period is not vagally mediated. Bradycardia IS indicative of myocardial hypoxia and/or hypothermia.
The heart rate in a neonate with a body temperature of 96°F is 200-250 bpm (beats per minute). Be aware that severely hypoxic
puppies may have heart rates in the expected range for adults of their breed. If the rectal temperature drops to 70°F, the
heart rate decreases to 40-50 bpm. However, the hypothermia protects neonates from ischemic brain injury that accompanies
Administration of chronotropic agents is, at best controversial. Parasympatholytic agents such as atropine will only exacerbate
cardiac hypoxemia via increasing oxygen consumption and demand. The more appropriate treatment for neonatal bradycardia is
to supplement oxygen and assist ventilation, if necessary. Remember that atropine crosses the placenta while glycopyrrolate
does not. This is important when considering choice of medications to be administered pre-or intra-operatively to a dam undergoing
a caesarian section delivery.
Hypoxemia in the neonate may result in life threatening sequelae such as septic shock due to bacterial translocation despite
a lack of mucosal lesions. It is vital that the environment be kept free of airway irritants and oxygenation is adequate.
If you choose to provide services that require resuscitation of neonates, you will need an oxygen source. If you do not have
a second anesthesia machine that can be used for oxygen administration, an oxygen concentrator is an inexpensive oxygen delivery
system. An oxygen concentrator concentrates room air to >95% oxygen.
Unlike their homeothermic adult counterparts, neonates are poikilothermic and are unable to regulate their own body temperature.
They can lose heat through evaporation, conduction, radiation and convection and they cool quickly. Shivering and vasoconstrictive
reflexes are not yet functional. However, they have well developed behavioral heat seeking responses which enable them to
maintain a stable rectal temperature providing sources of heat are available.
Prevention of hypothermia in neonates is extremely important. Without a heat source, hypothermia ensues and resuscitative
measures lose their effectiveness. Due to incomplete maturity of the autonomic nervous system, the neonate is less able to
respond to physiological stress. Physiological responses noted during hypothermia include bradycardia, cardiovascular failure,
neuronal injury, and ileus. Body temperature is known to have a dramatic effect on gastrointestinal movement in the neonate.
At rectal temperatures below 94°F, ileus develops. As ileus progresses, the willingness to nurse decreases and the necessity
for tube feeding puppies increases. Inherent to the tube feeding process is the risk for aspiration and subsequent development
Normal rectal temperatures in the puppy are 95 - 99°F (week 1), 97 - 100°F (weeks 2 and 3) and by weaning rectal temperatures
approach that of the adult. The challenge is to maintain the body temperature of the neonates without overheating the dam.