Effective administration route of azadirachtin and its impact on haematological and biochemical parameters in goldfish (Carassius auratus) infected with Aeromonas hydrophila

The purpose of this study was to determine the changes in the haematological and biochemical parameters in Carassius auratus infected with Aeromonas hydrophila and treated with various doses (1, 50, and 100 mg kg⁻¹) of azadirachtin administered through different routes: intraperitoneal (IPA.), intramuscular (IMA.), dip treatment (AD), and enriched diet, and examined 30 d later. In infected untreated group (IU), the white blood cell count (WBC: 10⁶ mm⁻³) decreased significantly (P<0.05) as compared with the control. In the infected and treated groups: IPA, IMA, AD it decreased (P<0.05), whereas in the azadirachtin fed group (AF) the WBC level did not increase when compared to the control (P>0.05). In both IU and treated groups the red blood cells (RBC, 10⁶ mm⁻³) significantly declined (P<0.05). In IMA, AD, and AF groups, the haemoglobin (Hb, g dl⁻¹) and haematocrit (Ht: %) levels did not decrease (P>0.05), except in the AF group (P<0.05). The erythrocytic indices, like mean corpuscular volume (MCV, µm³) and mean corpuscular haemoglobin (MCH, pg) level in the AD and AF groups, did not vary when compared to control values. However, the MCV, MCH, and mean corpuscular haemoglobin concentration (MCHC, %) significantly differed (P<0.05) in the IPA and IMA groups. Interestingly, in the AD and AF groups the percentage of lymphocytes, monocytes, eosinophils, and neutrophils, did not differ (P>0.05) from the control. However, the cholesterol (CHO, mmol 1⁻¹) and calcium (CAL, mmol l⁻¹) levels significantly differed (P<0.05) at 50 and 100 mg⁻¹ doses, whereas the total protein (TP, g dl⁻¹) and glucose (GLU, mg dl⁻¹) did not change (P>0.05) from the control values. The study indicates that the administration of azadirachtin through dip treatment or enriched diet could be effectively used to promote the health status of gold fish infected with A. hydrophila.