Determination of the Efficacy of Streck Cell Preservative Added to EDTA-Treated Whole Blood from Koalas (Phascolarctos cinereus) to Facilitate Field-Delayed Complete Blood Counts
American Association of Zoo Veterinarians Conference 2015
Christine M. Molter1, DVM; Kendal E. Harr2, DVM, DACVP; Mollie Zaback3, DVM; Philip H. Kass4, DVM, PhD, DACVPM; Laura Keener1, MT, ASCP; Geoffrey W. Pye1, BVSc, MSc, DACZM
1Veterinary Services, San Diego Zoo Global, San Diego, CA, USA; 2Urika Pathology, Mukilteo, WA, USA; 3Center for Birds and Exotic Animal Medicine, Bothell, WA, USA; 4School of Veterinary Medicine, University of California Davis, Davis, CA, USA
Field health assessments of free-ranging koalas (Phascolarctos cinereus) in remote study sites may lead to delayed testing of whole blood for complete blood counts (CBC). Streck Cell Preservative is a proprietary liquid stabilization reagent that may potentially extend blood cell integrity and morphology, which could be beneficial when processing of blood is not possible in a timely manner. To determine if Streck Cell Preservative is an efficacious method for the preservation of EDTA-treated whole blood from koalas, a study involving 12 captive adult koalas was performed. During routine health assessments, blood from koalas was opportunistically collected into EDTA-coated tubes. Following collection, a sub-sample of EDTA-treated blood was mixed with Streck Cell Preservative at a 1:1 dilution. The paired samples of EDTA-treated blood with and without Streck Cell Preservative had serial CBCs performed on days 0, 1, 3, 7, 10, and 14 post-collection. Data was analyzed by mixed effects ANOVA and post-hoc paired sample t-tests. Over time, the Streck Cell Preservative treated blood samples showed less cellular lysis than untreated samples, particularly after 7 days. Therefore, Streck Cell Preservative extended the viability of the blood sample up to 14 days and provided greater accuracy and precision of cell counts compared to blood remaining in EDTA alone. In conclusion, Streck Cell Preservative represents an effective method to preserve EDTA-treated whole blood in koalas and may be used with confidence during field research.
The authors thank Dr. Alan D. Marcus and Dr. Damien P. Higgins for providing the impetus for this study. Additionally, the authors are grateful to the veterinarians, veterinary technicians, laboratory technicians, and animal care staff for their dedication to the care of the koalas at the San Diego Zoo and for their participation in this project. The opportunistic collection of blood for this study was approved by the San Diego Zoo Global Institutional Animal Care and Use Committee (12-023), and San Diego Zoo Global has an Animal Welfare Assurance (A3675-01) with the Office of Laboratory Animal Welfare.