Mass bird deaths in Rajasthan, MP have prompted authorities to take remedial measures.
Officials said 175 crows, other birds were reported dead across Rajasthan on Monday alone.
In neighbouring Madhya Pradesh, over 500 crows have died over the last week.
MP officials said they were mixing antibiotics in water bowls for birds in affected areas.
In Rajasthan, expert teams have been rushed and surveillance enhanced around poultry farms. Rajasthan's animal husbandry department officials said they were collecting samples from wetlands.
In Madhya Pradesh, animal husbandry department officials said birds there have died of bird flu.
Surveys are also reportedly being conducted to check the impact of bird flu among humans.
