Vol. 11, Special Issue 1 (2022)

Author(s):
Prashanth Anur Gopal, HD Narayanaswamy, ML Sathyanarayana, Suguna Rao, D Rathnamma and Divakar Hemadri

Abstract:
The present study mainly focussed on respiratory tract pathology and molecular diagnosis of field occurrences of ILT in 783 chickens from 50 chicken farms in Karnataka during May 2017 to May 2018. Among 200 pooled tracheal samples from 50 farms, 24 samples belonging to six layer farms were positive for ILT by PCR results. Clinical signs included nasal discharge, infraorbital swelling, dyspnoea, expectoration of bloody mucus with depression. Post mortem lesions revealed respiratory tract inflammatory changes, laryngo-tracheal hemorrhages with mucous plug and diptheretic membrane formation, congestion and edema of lungs with patchy hemorrhages, pleuritis, polyserositis and airsacculitis. Histopathologically, degenerative and hyperplastic changes in laryngo-tracheal region consisting of syncytial epithelial giant cell containing eosinophilic inclusion bodies were mainly recorded. Analysis of sequencing by phylogenetic tree construction revealed 100% similarity between field and few CEO vaccine strains as far as the 688bp ICP4 gene segment was concerned.