Experimental Study On The Pathology Of Piglets Pseudorabies (Aujeszky's Disease)

A pattern of piglets pathogenesis of eighteen 15-day-old naive piglets of 2 litters intramuscularly given EA strain of pseudorabies virus was studied. Group 1 contained 10 piglets of which 8 given 105TCID50 of infectivity titer and 2 as control. 8 piglets of group 2 inoculated 1075TCID50of infectivity titer. The test items were symptomatic and pathologic changes, indexes of blood routine examination, results of transformation of lymphocyte for peripheral blood(%) and serum antibody.The results showed that all of the inoculated piglets developed pseudorabies characterized by the symptoms of mild fever, diarrhea, breathe with difficulty, and 5-to-7-day-duration muscular twitchings and tremors, incoordination, paralysis, subsequent occurring. The mortality of group 1 and 2 was 12.5% (1/8) and 62.5% (5/8) respectively. Necropsy changes, such as meninges congestion or hemorrhage, pulmonary emphysema or pneumorrhagia, lymph nodes enlargement and hemorrhage, hemorrhage dots appearing surface of kidney was showed. The neuro- pathologic lesions were non-suppurative encephalomyelitis, ganglionitis, and neuron necrosis. The histopathologic changes in other internal organs included interstistial pneumonia, necrotic spenitis, necrotic lymphnoditis, thrombosis were observed in many tissue. Intranuclear inclusions were observed in neurons of CMS, liver, kidney and lymphnodes. Ultrastructurally, necrosis was present in neurons of CMS and the cells of liver and kidney. Two pigs conducted obvious pruritus after inoculated with 1075TCID50 pseudorabies virus.The 2 naive piglets developed fever and diarrhea but no CMS relative sign in the6th day of post-inoculation in their litter and was shown positive to PRV by latex agglutination test (LAT) in the 7th day of post-inoculation and positive to PRV by serum neutralization test (SNT) in the 14th day of post-inoculation.Of 7 inoculated piglets in group 1, 3 were showed positive to PRV by SNT in the 7th day of post-inoculation, comparison of all showed positive to PRV by LAT. Along with the infective days, the lever of antibody became higher., SNT titter reaching to 1:154.3 in the 28th day of post-inoculation.In the 7th day of post-inoculation, the results of transformation (%) of lymphocyte of inoculated piglets were shown very signification higher than that of pre- inoculation (P=0.007), and signification higher than that of the control piglets of the corresponding time (P=0.04).The amount of WBC of post-inoculation was shown signification higher than that of pre- inoculation (P=0.019). the amount of lymphocytes has the tendency of increasing after infection, but not signification different (P=0.12). The amount of platelets (PLT) after infection decreased in all of the two groups, with group 1 not signification different (P=0.18), group 2 having signification different (P=0.04). The change of PLT amount possibly played an important role in pan-hemorrhage of a number of internal organs.