Hematology and Blood Chemistry Values in Cuban Crocodiles (Crocodylus Rhombifer) Housed at the Zapata Swamp Crocodile Farm, Cuba

Abstract

We report hematology and biochemistry reference intervals (RI) for the critically endangered Cuban crocodile (Crocodylus rhombifer). In November 2019, we sampled 43 adult crocodiles (6 male, 37 female) under human care at the Zapata Swamp Crocodile Farm in Matanzas, Cuba. These crocodiles are part of a breeding program for the species registered by the Convention on International Trade in Endangered Species (CITES). Visual health evaluations were performed immediately after manual restraint, and blood was collected from the postoccipital sinus. We performed packed cell volume (PCV), total solids (TS), complete blood counts (CBC), and biochemistry profiles for each crocodile on the day of sampling. Mean PCV (n ¼ 42) was 21.1 6 5.0% and TS (n ¼ 42) 7.3 6 1.2 mg/dl, respectively. Absolute white blood cell (WBC) (n ¼ 40) was 9.6 6 5.7 3 10 9 /L. Similar to other crocodilian species, the dominant leukocyte was lymphocytes (70.7 6 10.4%), followed by heterophils (18.7 6 9.7%). Two of the crocodiles had a high heterophil:lymphocyte ratio (0.87 and 0.74), although on visual exam they were both considered healthy. The range of creatine kinase was 41-1,482 U/L, and the higher values may be a reflection of muscle exertion at time of handling. Limitations to the study included skewed sex ratios and high lipemia and hemolysis in most samples collected. These are the first reference intervals reported for this species, including the first descriptions of WBC morphology. These data are valuable for the management of animals at the Zapata Swamp Crocodile Farm, for comparison with free-living Cuban crocodiles in Cuba, and for comparison with those managed under human care outside of Cuba.