Haematological Characteristics of Clarias gariepinus Exposed to Graded Levels of Dexamethasone

Abstract

A feeding trial was conducted for seventy days in order to evaluate the effect of dexamethasone on the haematological parameters of Clarias gariepinus juveniles. The fish were fed with diets containing four different levels of inclusion of dexamethasone which were: 3mg/kg, 6mg/kg, 9mg/kg and 12mg/kg. However, the diet fed to the fish as the control had no inclusion of the additive. At the end of the experiment, blood samples were obtained from all the treatments and were analyzed to determine their haematological parameters and electrolyte composition. The study revealed that Erythrocyte sedimentation rate (ESR) and packed cell volume (PCV) were not significantly different from those of the control except in the treatment fed with diet containing 6mg/kg of dexamethasone (p˂0.005). Also, red blood cell counts (RBC) in all treatments differed significantly from the control except in the one fed with a diet containing 12mg/kg of the additive (p˂0.005). The white blood cell counts (WBC) in all treatments differed significantly (p˂0.005) from and were higher than that of the control except in the one fed with a diet containing 9mg/kg of the additive. Haemoglobin concentrations were also not significantly different (p˂0.005) from that of the control in all the treatments. In addition to that, blood sodium levels in all treatments were significantly different from that of the control, while calcium concentrations only differed significantly from the control in fish fed with diets having 3mg/kg, 6mg/kg and 12mg/kg inclusions of dexamethasone respectively (p˂0.005). Moreover, blood magnesium and potassium levels in all treatments were not significantly different from that of the control (p˂0.005). This study has therefore shown that the doses of dexamethasone included in the diets of C. gariepinus juveniles induced some changes in the haematological characteristics and ionic composition of their blood and could consequently induce negative changes in their physiology and health status.