Infectious Coryza, known as fowl coryza, is a disease of upper respiratory tract caused by Haemophilus gallinarum. The outbreaks of infectious coryza have been described earlier by various workers¹,² in different parts of the world. The present communication reports an outbreak of coryza in 10 weeks old Vanaraja poultry birds of Meghalaya.

The Vanaraja chickens were newly introduced in Meghalaya under NATP Jai-Vigyan Project on backyard poultry production from project directorate on poultry; Hyderabad and birds were distributed to the farmers after 6 weeks of rearing at the Institute nursery. The birds of the Institute as well as those from farmers’ field were found affected by infectious coryza outbreak. Clinical signs and symptoms manifested by the sick birds were recorded and postmortem was conducted on the carcasses and gross changes were recorded. Representative tissue samples were collected in 10% formalin for histopathological examination. For bacteriological examination, interorbital and nasal secretions were collected in transport media and cultured on Chocolate blood agar to ascertain the presence of Haemophilus gallinarum organisms. Sensitivity of the isolates to different antibiotics was also determined by using standard discs as per standard method³. Out of the 501 birds, a total of 205 (40.91%) birds belonged to Institute farm as well as farmers’ field were affected due to infectious coryza. Out of 205 birds affected, two birds in Institute farm and five birds in farmers’ field died due to infectious coryza.

The clinical signs recorded in the present outbreak were nasal discharge, swelling of the sinuses, severe foamy lacrimation (Fig. 1) and conjunctivitis along with reduction in the feed intake. These observations made in this study were in accordance with the lesions described for turkeys⁴. The sick birds were treated with Enrofloxacin @ 5mg/kg body weight orally for seven days. Out of 205 affected birds, 198 birds were able to recover completely within 7 days. At necropsy, it was found that gross lesions were restricted to the upper respiratory tract only. There was presence of catarrhal exudate in the upper respiratory tract mainly in the nasal cavity. In two birds, lungs showed mild to moderate degree of congestion and consolidation. The mucous membrane of the eyelid was congested. The gross lesions recorded in the present investigation were in close resemblance to induced Haemophilus gallinarum infection in chicken⁵. Microscopically, nasal mucosa showed severe infiltration of mononuclear cells, particularly in the lamina propria. The lungs showed congestion and mild diffuse haemorrhages. Almost similar microscopic lesions were described earlier⁵. The pneumonic lungs showed thickening of interlobular septa due to infiltration of mononuclear cells. Isolation study revealed the presence of Haemophilus gallinarum organism in the interorbital and nasal secretion of both ailing and dead birds. The antibiotic sensitivity test showed sensitive to Enrofloxacin, Ciprofloxacin, Gentamicin, Chloramphenicol and resistance to Ampicillin, Cloxacillin and Penicillin.

Fig. 1:Infectious coryza: Severe foamy lacrimation and conjunctivitis.

An outbreak of infectious coryza in vanaraja poultry of meghalaya