It is a viral disease caused by “Orthomyxo virus”. There are two types of AI which are characterized by low pathogenic avian Influenza (LPAI) and highly pathogenic avian Influenza (HPAI).
Most commonly found clinical signs which are found in the birds affected by AI are coughing, sneezing, nasal and ocular discharge, rhinitis (sticky nose), difficulty in breathing, swollen head, comb, wattles, purple coloration of the comb, accumulation of fluid in eyelids, pin point / cutaneous haemorrhage on shanks and claws of the bird,greenish – white diarrhoea and pasting on vent, weak shell / shell less eggs in laying hens, subcutaneous oedema in the lower intermendibular space of the neck, depression, stargazing posture (upward lifting of neck due to nervous disorder), high fever about 45 C and ruffled feathers.
Bleeding / haemorrhage on ovaries. Dhaemorrhages in gizzard, small intestine, trachea and in base of proventriculus.
Dark red muscles of breast and legs.
Congested, oedematous and haemorrhagic lungs.
Abdominal air sac become cloudy.