Iris - toxic?

I have just had a nosey at the poultry information and found a link to toxic plants (to cats). Iris is listed, and I have some iris bulbs (leaves only at the moment) in my chicken run...  :shock:

The link isn't working to the information though, does anyone know anything about them?

Looks like i may be getting my shovel out in a minute...

My chooks have been nibbling them the last 2 days.. since they arrived.. so took no prisoners this morning and dug them out! I do have about 3 other clumps in the back garden and a lot in a front garden border, so will have to have a think about them.. haven't caught the dogs eating them so they may get to stay. I hate getting rid of plants that are pretty but didn't want to risk the girls being ill.