LAUSR

Abstract The North Carolina State University College of Veterinary Medicine Turtle Rescue Team (TRT) regularly admits wild eastern box turtles (EBT) (Terrapene carolina carolina) for treatment and rehabilitation. Adult males of this species generally have an impressive red coloration of the iris, a feature commonly used to differentiate them from their brown-eyed female conspecifics. Male EBTs that present often display marked pallor of the eyes, which has accompanied clinical anemia. The aim of this study was to examine the relationship between eye color and packed cell volume (PCV) in adult male EBTs, and to assess the accuracy of using eye color to predict PCV. Eye-color scoring cards were created using Adobe Creative Cloud Photoshop®. Each card was composed of blocks displaying progressively lighter tints of a red hue, with a number (score) assigned to each block. Five-block, six-block, and nine-block scoring cards were prepared, with lower numbers (scores) corresponding to lighter hues. To determine the variation in subjective color scores assigned by different human observers, 85 individuals were asked to score EBT eye color in three animals using each of the three scoring cards. Eye color of adult male EBTs that presented to the TRT (n = 18) and those housed at the North Carolina Museum of Natural Sciences (n = 6) were scored using each of the three cards, immediately preceding venipuncture of the occipital sinus for determination of PCV. All animals were scored by at least two individuals. Turtles with low scores (pale eyes) using all three scoring cards consistently had lower PCVs. The five- and six-block scorecards had a positive predictive value (PPV) of 100% while the nine-block score card had a PPV of 71.4%. This specific and noninvasive method for estimating PCV of male EBTs is clinically desirable in both rehabilitation and hospital settings.