Is needing an item from a different spec considered ninja?

Say for example if I join a dungeon as DPS and play Fury, can I need a Shield from a boss or is it considered ninja?

Shouldn't be so long as someone there doesn't need it for their MS. Don't be a dick and need on tank gear if you are dps and the tank needs the item. A little more tricky is the healer, since healer items can have good stats for certain dps at the rdf hc level. For me personally, I either ask before needing, or check to make sure no one else needed before needing for offspec.

It is, don't do it without asking.
Ask in chat if it's ok to need and wait for a reply, if nobody says anything assume it isn't and hit greed.
Most of the time, people are understanding enough, sometimes they arent.

I'm asking because I was the tank and and a dps needed the shield and left saying it was not ninja. I'll report him thanks.