Reference Ranges for Prothrombin Time,Activated Partial Thromboplastin Time and Platelet Count in Llamas and Alpacas

The objective of the study was to establish reference ranges for prothrombin time, activated partial thromboplastin time and platelet count in normal, healthy adult llamas and alpacas. The sample population comprised 28 llamas of both sexes, ranging in age from 1 to 9 years, 28 alpacas of both sexes, ranging from 1 to 9 years old. Jugular venous blood samples were collected to measure prothrombin time, activated partial thromboplastin time and platelet count. These values were used to establish reference ranges for each of these parameters. The data obtained for both the llamas and alpacas was normally distributed. Mean partial thromboplastin time for the llamas was 7.35 (± 0.29) s and for the alpacas was 7.44 (± 0.59) s. Mean activated partial thromboplastin time for the llamas was 12.44 (± 1.67) s and for the alpacas was 12.16 (± 1.53) s. Mean platelet count for the llamas was 423 607 (± 187 441)/μl and for the alpacas was 499 643 (± 152 651)/μl. The results demonstrate some important differences between ranges determined for prothrombin time, activated partial thromboplastin time and platelet count in llamas and alpacas, and the reference ranges already established for other domestic species. Correspondence and offprint requests to: Dr A. N. Baird, Ass. Professor of Surgery, Dept of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, 1248 Lynn Hall, West Lafayette, IN47907-1248, USA. e-mail: abaird@postoffice.purdue.edu