The ABC's of managing critical problems in neonates (Proceedings)
Average puppy and kitten deaths during the first 12 weeks of life approach 11%-34%. Still births or death within the first 24 hours account for 5% of the losses; an additional 5% loss occurs during the neonatal period; and 0%-5% loss in transitional & socialization periods. Infectious diseases are not the most common cause of neonatal or transitional period mortality.
Birth weight / weight gainBirth weight is the single most important predictor of neonatal survival. Those neonates that are < 25% of the litter average weight are at particularly high risk for hypoglycemia, hypothermia, hypoxia, bacterial septicemia and pneumonia. Close observation and careful monitoring are paramount to their survival chances. Monitoring weight gain is a good indicator of health status. Health Monitoring: Signs of healthy vigorous neonates include; adequate weight gain, strong activated sleep patterns, firm muscle tone and strength, and not crying. Crying for over 15 minutes is a signal and should not be considered normal. Puppies cry when hungry, neglected (separated or culled), in pain, and especially when cold.
Thermoregulation is problematic in the neonate. Chilling is always a major threat to the survival of the neonate. The shivering reflex and peripheral vasoconstriction response are not fully developed until at least 1 week. Their relatively large surface area, plus the lack of insulating fat, promotes rapid heat loss by conduction, convection, radiation, and evaporation. The vulnerable young must relay on warmth of the dam and litter and environment to maintain an adequate body temperature. Mothers who refuse to "gather" the young or lick the young excessively, or "cull" one or two of the young, places these individuals at high risk for hypothermia. Hypothermia is a common cause of death in the newborn and is part of a viscous down spiraling cascade of events. As the rectal temperature reaches below 94° F the neonate suckling becomes weak and ineffectual. The intestines become hypomotile and the heart rate increases. Below 85° F there is gastrointestinal stasis with bacterium, a decrease in heart rate and hypoglycemia. Once below 70° F, the neonate is motionless and appears appear dead. An occasional chest wall movement may be seen, but the heart rate is 40-60 b/min and is non-palpable. Environmental temperature can be critical as a healthy newborn can only maintain a body temperature 12°F > than that of the surrounding environment.
Hypothermic patients should be re-warmed slowly (1-2 hours) to a temperature of 98°- 99°F. Warming increases the respiratory and heart rates; increases effectual nursing and swallowing reflex; increases visceral movements; and mobilizes glycogen stores. This warming process is essential prior to attempted feeding. Maintain the neonate in a draft-free environment. Re-warming is best accomplished with a human neonatal incubator. A thermometer should be used to measure ambient temperature. Focal heat sources such as circulating hot water blankets, warmed rice bags and hot water bottles insulated with towels may also be used. Whenever a focal heat source is used, a temperature gradient should be created to allow the neonate to either move to or away from the heat source. Overheating is rarely a problem but panting with hyperemic membranes and skin is a clue. Heat lamps and electric heating pads are not recommended because of increased the risks of burns and overheating. Remember to turn the patient every 20 minutes while taking the temperature.
Hypoxia is a common sequel to birthing. Many newborns would benefit from short term supplemental oxygen therapy and respiratory stimulants. Those neonates with pneumonia or sepsis often require supplemental oxygen via an oxygen tent, oxygen cage, nasal tube or face mask (short-term only). Arterial blood gases are nearly impossible to collect and unavailable to most practices. However, a pulse- oximetry can sometimes be placed on the hairless skin of the ventral abdomen. Unfortunately an accurate reading requires adequate circulation not often present in a shock neonate. The normal oxygen saturation is > 90%.