INFECTIOUS CORYZA

acute / subacute respiratory disease of chickens -nasal discharge, sneezing, and swelling of the face under the eyes.

Agent:Avibacterium paragallinarum, a gram-negative, pleomorphic, nonmotile, catalase-negative, microaerophilic rod that requires nicotinamide adenine dinucleotide (V-factor) for in vitro growth
isolation requires cocultivation with a “feeder” culture such as Staphylococcus ...



INCUBATION PERIOD-
1 to 3days- 1-3 weeks bc chronic/ persistence, aggravated by cold, damp weather,
2nd infection-chronic condition
Mortaility- poor mgm/ unsanitary condition, 2nd infection increase mortality

T- Carrier birds, direct contact, airborn droplets, contaminated dropplet, no egg transmission

CS-
clear nasal discharge bc thick , purulent
severe unilateral/ bilaterals swelling of infrorbital sinus , eye swell up, close
yellowish dry crust around nasal opening
dyspnea
offensive odour of nasal discharge



Lesion-
limited to the infraorbital sinuses, copious, tenacious, grayish, semifluid exudate. in early stage
As the disease becomes chronic or other pathogens become involved, the sinus exudate may become consolidated and turn yellowish. 

 conjunctivitis, tracheitis, bronchitis, and airsacculitis
H-isintegration and hyperplasia of mucosal and glandular epithelia and edema with infiltration of heterophils, macrophages, and mast cells.