What is causing the swelling around this 3 year old chicken’s eye?
This is a typical case of intraorbital sinusitis, probably of bacterial or mycoplasmal origin as described by Pass and Riddell in (Chronic rhinitis and sinusitis in budgerigars (Melopsittacus undulatus). Avian Dis. 1987 31:425-7) and by Chin and Goshgarian (Infraorbital sinusitis associated with Pasteurella multocida in pen-raised ring-necked pheasants. Avian Dis. 2001 45:540-3). The infraorbital sinus passes around the inferior margin of the globe and extends into the posterior part of the orbit, hence any inflammation there leads to periorbital and conjunctival swelling as seen here.
