Effects of Gestational Age on Physical Findings of Immaturity, Body Weight, and Survival in Neonatal Alpacas (2002–2010)

Abstract

Gestational duration is highly variable in camelids (reference range 330-360 days), and a definition for prematurity has not been established. Anecdotally, it is suggested that crias born outside of this have increased incidence of physical findings of immaturity (tendon laxity, floppy ears, and unerupted teeth) and need increased intensive support in the neonatal period. Low gestational age (<330 days) is associated with physical findings of immaturity, low birth weight, more intensive and expensive care, but not decreased short-term survival. A total of 130 alpacas presented to the University of Wisconsin. Retrospective study of all neonatal crias <1 month of age. Of 130 neonatal alpacas presented, 86 (66%) had gestational age recorded (range 312-393 days). There were 16 (18.6%) crias with gestational age below 330 days. Crias born before 330 days were lighter at birth (mean 6.4 kg, SD 1.3 kg) than those born after 330 days (mean 7.4 kg, SD 1.7 kg, P = .002). Clinically immature crias had lower birth weights (mean 6.5 kg, SD 1.5 kg) than physically mature crias (mean 8.8 kg, SD 3.2 kg, P = .05). Survival rates were similar in all groups (premature 77%, mature 88%, P = .12). However, treatment costs were higher in crias born prior to 330 days with physical findings at birth consistent with immaturity compared with gestationally mature crias and those born prior to 330 days but with a physically mature appearance. Crias born before 330 days and those with physical findings of immaturity have a good prognosis, but require more intensive care, resulting in higher treatment costs.