Prevalence of haemoparasites in captive crocodiles (Crocodylus niloticus) and associated haematological changes

Abstract

The increase in awareness and practice of reptile domestication has led to more knowledge of reptiles medicine in Nigeria. However, with this awareness, there is a paucity of information on the clinical presentation of crocodiles in health and disease. A study was therefore carried out using ten 21⁄2 to 3 years old captive juvenile crocodiles Crocodylus niloticus with live body weights of 1.5-3 kg having haemo-infection. Three millilitres of blood was collected through the caudal tail vein for haematological analysis. A blood smear was used for morphological identification of haemoparasites. The haematological values obtained were; PCV (%) 25.70 ± 4.3, Hb (g/dl) 7.80±6.6, RBC (×10⁶/μl) 1.24±0.37, MCV (fl) 197.50±25.72, MCHC (g/dl) 33.6±1.33, Platelet (μl) 112,800±46,168.29, WBC (10³/μl) 6595±1,594.80, lymphocytes (μl) 3,544±1238.60, heterophils (μl) 2,670±999.3, monocytes (μl) 2.0±1.0, eosinophils (μl) 136 ± 8.0 and the basophils (μl) 111 ± 87. There was no significant difference (P>0.05) in all the haematological parameters except for eosinophils and basophils which were significantly increased in the naturally infected crocodiles. Haemoproteus, Plasmodium and Hepatozoon species were morphologically identified in this study. There was no significant clinical alteration in haematological profiles obtained with haemoparasiteamia in this study. The findings from this study could serve as baseline values for clinical diagnostic investigation in our environment.