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 associated with chronic heat stress in sheared versus nonsheared alpacas. Fourteen intact male adult alpacas were randomly assigned to one of the two groups: Group S alpacas were sheared to within 2cm of their skin; Group NS alpacas were not sheared. These animals were maintained from June through August in east central Alabama. Data collected in the morning, every two weeks, included vital signs, body weight, body condition score, complete blood counts, serum chemistries and electrolytes, whole blood selenium, and plasma cortisol. S and NS groups were contrasted using the repeated measures analysis of variance, and pertinent correlations with weather parameters were calculated. Clinical heat stress was not evident in any animals during the study. Significant differences between treatment groups were seen in rectal temperature (P=0.0095), sodium concentration (P=0.0219), and blood urea nitrogen (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 normal limits in both groups at all sampling times. Rectal temperature of only the S group was positively correlated to weather parameters. Sodium of both S and NS groups and BUN of the NS group were negatively correlated with weather parameters. This study indicates that there are differences between sheared and nonsheared alpacas in physical examination and clinicopathologic parameters that can be correlated with changes in ambient conditions. These differences suggest that nonsheared alpacas are less heat tolerant than sheared alpacas. Therefore, shearing is recommended for animals exposed to similar conditions.