SKUAST Journal of Research

Secondary infections following immunosuppressive affections modulate or accentuate the clinical, clinico-pathological and pathological spectrum of both primary and secondary affection. Present study was aimed to investigate the haematological alterations due to Pasteurella multocida 12A infection in sub-acute ochratoxin-A (OT-A) intoxicated rabbits. New Zealand White rabbits of 8 weeks age, weighing 350–400 g, were allotted randomly to six groups having 10 animals each. Group-I and II rabbits were maintained on control diet, group-III and IV rabbits received 1000 ppb OT-A diets, and group V and VI received 2000 ppb OT-A diets. Rabbits in groups II to VI were infected with P. multocida 12: A strain on the 22^nd day of experimentation, by intranasal inoculation of 1 ml of 18 hr old broth culture (@ 1 x 10⁶ CFU) when toxin was withdrawn from groups IV and VI. The experiment was carried out for 7 weeks and haematological investigations carried out on 0 day and then at weekly intervals. The study revealed that P. multocida infection in OT-A intoxicated rabbits caused significant (P < 0.05) decrease in Hb, PCV, TLC, lymphocyte counts where as ESR, clotting time and heterophil and monocyte counts increased significantly. Dose of OT-A and withdrawal of toxin at the time of infection did not significantly affect haematological changes following infection. It was concluded that immunosuppression caused by OT-A intoxication favours establishment of infection with P. multocida 12A leading to marked haematological alterations.