Happy K. Shieh;Y.L. LiJ.R, Shiau.Y. Yang.C.H, Wang;K,Y. Kao;Y,S. Lu$,S. Author Chen
Chickens with clinical signs of infkaorbital swelling, moist rale, cx)ughing, gasping. blocd-stained nasal discharge were observed in a mixed breed broiler farm (with si of abcnrt sixty thousand chickens) at southern area of Taiwan in January, 1979. The morbidity was abcnrt5O% and with 5% mortality. Gross lesions of the moribund or dead birds observed were mainly in laryngeal, tracheal and lung tissues. Tissue changes included mucoid inflammation, congestion, hemorrhage, and the inflammatory exuda varied from mucoid, casecus, to blood-tinged exudae or even blood clot. No jtdcular change was noted in the other visceral organs. Slightly acidophilic type A intranuclcar inclusion bodies could he found in epithelial cells of trachea. The emulsions of trachea or lung tissue, afr inoculation choricellantoic membrane (CAM) or into allantoic cavity of emixyonati eggs, caused CAM swelling and formation of opigue picks. Rounding and refractory cell changes could he noted in chicken kidney cell cultures aft inoculation with the isolati virus. Spthflc fluorescence could he found in infected CK culture teal with conjugated LT antibody. The isolate induct:! mild infectious laryngotracheitis sings in LT antibody freechickensofbweeksofage.
The clinical observations, thological findings, virus isolation, and serological result lead to a diagnosis of infectious laryngotracheitis.