A suspected outbreak of avian flu at an egg farm has led Woolworths and Coles to limit egg purchases to two cartons per person on the east coast.

The bird flu outbreak is affecting poultry farms, resulting in empty shelves in stores in NSW, ACT, and Victoria.

Egg packing sheds have been temporarily closed, and egg purchase restrictions are in place in all states except WA.

McDonald's has adjusted its breakfast menu window to conserve eggs.

Over one million birds have been culled to contain the spread of the avian flu.