Haematologic and Biochemical Parameters of Haemogregarine-infected and Non-infected African Hinge-Back Tortoises in Ibadan, Nigeria

Abstract

This study was conducted to evaluate haematological and biochemical parameters of haemogregarine-infected (h-infected) and
non-infected African hinge-back tortoises in Ibadan, Nigeria. Blood samples were collected from 120 tortoises, of which 70 were Kinixys belliana and 50 were K. homeana. Stained thin smears were examined for haemogregarines using light microscope. Haematological and biochemical analyses were carried out following standard procedures. A total of 91(75.83 %) tortoises were positive for haemogregarines. Significantly (P<0.05) lower values of haematocrit (23.92 %), haemoglobin (5.21g/dl) and mean corpuscular haemoglobin concentration (MCHC) (21.78 %) were recorded for h-infected tortoises with haematocrit (33.29 %), haemoglobin (8.31g/dl) and MCHC (24.96 %). Higher values of white blood cells (WBC) (7.26 x 10⁹ /L) and lymphocytes (2.71x10⁹ /L), were observed in h-infected than non-infected with WBC (5.58 x 109 /L) and lymphocytes (2.15x10⁹ /L). Higher values of haematocrit and haemaglobin were recorded for K. Homeana. Males had higher haematocrit (27.27 %) and WBC (7.09 x 109 /L) than females with haematocrit (24.35 %) and WBC (6.93 x 10⁹ /L). Females had higher MCHC, haemoglobin and calcium values than males. The lower values of haematocrit, haemoglobin and MCHC obtained for h-infected tortoises were expected since haemogregarines are usually found intra-erythrocytic in  their host thereby destroying affected erythrocytes and causing a decrease in haematocrit value. Higher WBC counts in h-infected tortoises is typical in diseased conditions. The higher level of calcium in female tortoises is due to their reproductive cycle  especially vitellogenesis and egg formation. Hypo-proteinaemia recorded in h- infected tortoises was attributed to parasitism. It is concluded that majority of haematological and biochemical analytes showed considerable variations with level of infection status, species and gender.

Keywords: Kinixys belliana; Kinixys homeana; Haematology; Plasma biochemistry; Haemogregarine parasites