Neonatal mortality (Proceedings)

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Neonatal mortality (Proceedings)

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Apr 01, 2008

Questions regarding neonatal mortality are common in general practice. Most serious breeders are well aware of the extent of neonatal losses and have a compelling economic incentive minimized those losses. Generally, clients with neonatal losses fall into one of the following categories the novice with their first or second litter and the dam being the house pet; hobby breeders having a couple litters yearly with a few of dogs; then the commercial breeders with a kennel of multiple animals. In the latter two instances neonatal deaths should be viewed in a "herd" health perspective which implies that extensive diagnostics and necropsies should be employed, and if necessary a very ill puppy or kitten may need to be sacrificed for necropsy in an attempt to obtain a diagnosis.


Mortality Bench Marks: (various studies)
Key time benchmarks for survival in our practice are birth then the first 24 hours, once that is achieved the first week is the most worrisome. Puppy and kitten losses in those who survive the first week are much more infrequent through weaning.


Normal Neonatal Body Temperature
The Primary causes of death in neonates are hypothermia, trauma, and malnutrition (starvation). Puppies do not have the ability to control their body temperature as adults. Neonates can become hypothermic for a variety of reasons either lost from mother (often trapped in bedding), pushed away from mother, low environmental temperature, poor mothering, the neonate gets wet, and illness. Puppies and kittens rely upon brown fat to maintain body temperature for the first week until they can shiver. Hypothermic neonates are incapable of digesting milk.

Traumatic injuries are responsible for up to 37% of mortalities. Traumatic injuries include birthing injuries, crushed, overzealous cleaning by dam, suckling by litter mates, and thermal burns from heat source errors among others.

Malnutrition or starvation can occur as a result of a weak neonate unable to hang on to teat, poor competitor with litter mates, structural issues like cleft palate, and hypothermia. Additionally, the dam may produce an insufficient milk supply, have mastitis, or won't lay down for babies to nurse. Neonates have minimal body fat reserves and limited metabolic capacity to generate glucose. Glycogen stores are depleted shortly after birth, making adequate nourishment from nursing vital. Even minimal fasting can result in hypoglycemia. Care should be taken when supplementing glucose to a neonate as they can easily become hyperglycemic since they have immature metabolic regulatory mechanisms.

Neonatal Indicators of Illness

  • Crying more than 20 minutes
  • Decreased activity
  • Separated from mother
  • Decreased muscle tone
  • Diarrhea
  • Rough hair coat
  • Panting or labored breathing
  • Decreased bowel sounds
  • Pale or cyanotic mucus membranes

Environmental:
Incorrect environmental temperature can cause several problems. Low environmental temperature forces the dam and puppy to use energy to maintain body temperature and places more stress on the babies. Elevated environmental temperatures cause the dam to be uncomfortable, she may be panting and refuse to lie with the neonates. Mom and puppies or kittens are spread out in the birthing area, which makes it more difficult for the offspring to find mom and nurse.

Incorrect selection of bedding materials allows for puppies and kittens to be trapped in the bedding, bedding which fails to absorb waste, does not wick moisture away from the offspring, and bedding which conducts heat away from neonates.

Correct husbandry techniques also involve proper hygiene to prevent infection, usually umbilical, leading to septicemia. Daily changing of the bedding is required at a minimum. Wet bedding allows for bacterial growth, becomes a heat sink causing hypothermia, and various dermatologic conditions.