A comparison of physical examination and clinicopathologic parameters between sheared and nonsheared alpacas (Lama pacos)

The purpose of this study was to determine the physiological changes associ ated with chronic heat stress in sheared versus nonsheared alpacas. Fourtee n intact male adult alpacas were randomly assigned to one of the two groups : Group S alpacas were sheared to within 2 cm of their skin; Group NS alpac as were not sheared. These animals were maintained from June through August in east central Alabama. Data collected in the morning, every two weeks, i ncluded vital signs, body weight, body condition score, complete blood coun ts, serum chemistries and electrolytes, whole blood selenium, and plasma co rtisol. S and NS groups were contrasted using the repeated measures analysi s of variance, and pertinent correlations with weather parameters were calc ulated. Clinical heat stress was not evident in any animals during the stud y. Significant differences between treatment groups were seen in rectal tem perature (P = 0.0095), sodium concentration (P = 0.0219), and blood urea ni trogen (BUN) (P = 0.0189). The mean rectal temperature of the NS group was above the normal range on five sampling times compared to only once for the S group. However, mean sodium and serum urea nitrogen levels were within n ormal limits in both groups at all sampling times. Rectal temperature of on ly the S group was positively correlated to weather parameters. Sodium of b oth S and NS groups and BUN of the NS group were negatively correlated with weather parameters. This study indicates that there are differences betwee n sheared and nonsheared alpacas in physical examination and clinicopatholo gic parameters that can be correlated with changes in ambient conditions. T hese differences suggest that nonsheared alpacas are less heat tolerant tha n sheared alpacas. Therefore, shearing is recommended for animals exposed t o similar conditions. (C) 2001 Elsevier Science B.V. All rights reserved.