Haematological reference intervals of the south american rattlesnake (Crotalus durissus terrificus, Laurenti, 1768) in captivity

Blood samples were taken from 180 healthy specimens of South American rattlesnake (Crotalus durissus terrificus) kept in captivity. The red blood cell count (RBC), haematocrit value, haemoglobin concentration, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) obtained were within the normal values reported for other Crotalid, Viperid and Elapid species. Total leucocyte (WBC) counts were within the range described in other ophidian species. No significant changes were observed as a function of sex and age. The period of the year (seasonal variation) was the only factor which had a significant influence on the haematological parameters. RBC counts, haematocrit, haemoglobin concentration, MCV, MCH and MCHC were 17-30% higher during winter-time (p