Pathology Of Induced Velogenic Viscerotropic Newcastle Disease (Vvnd) In Japanese Quail And Myna

The present study was designed to investigate the pathology and transmission of experimental velogenic viscerotropic newcastle disease (VVND) in Japanese quails and mynas. Both birds were divided into Q1, Q2, Q3, M1, M2 and M3 group each of four bird. The birds of group Q1, M1 and Q2, M2 were administered with 0.3ml of VVND virus (1.8 x10(9) EID10) via intramuscular and oral routes, respectively, whereas, birds of group Q3 and M3 were kept in contact exposure with VVND virus infected chickens. Clinical signs were observed in Japanese quails and mynas on 4th day post-inoculation. The major clinical signs were green yellowish diarrhea, ruffled feathers, anorexia and torticollis in all groups except Q3. The mean clinical scores and mean death time (days) were statistically non-significant (P>0.05) among all the groups. Higher mortality rate (75%) was recorded in mynas as compared to Japanese quails (50%). Major necropsy lesions observed were pin point hemorrhages in proventriculus, demarcated buttonlike ulcers of intestinal mucosa, hemorrhages in trachea and spleen. Histopathological lesions observed in proventriculus were erosions in epithelium, localized hemorrhages and congestion in the glandular region. In small intestine of affected birds, villi appeared hyperemic and ulcerated. Tracheal surface epithelium often showed discontinuation, the loss of cilia of the lining epithelium and disturbance of the coherence among various histological layers. In spleen, there was enormous infiltration with mononuclear lymphocytes, especially in the area of red pulp. Haemagglutination inhibition titer of all experimental groups was found higher on day 21 as compared to day 0 and 7. Taken together, experimental data showed the susceptibility of Japanese quails and mynas to experimental intramuscular and oral inoculation with VVND virus. Moreover, clinical VVND does not occur in Japanese quails upon contact exposure to VVND virus infected chickens although there is sero-conversion.