How to care for a young bird?

I found a young blackbird in my shed!
The shed has been shut for 2 days so it must have got in there whilst it was open and been trapped for 2 days.
I have taken it out of the shed and but it in a cage in the shade of my garden.
I have been feeding it wet dog food and water.
How long should I wait to let it go?

?2015-06-11T11:44:49Z

you can let it go as soon as you know for sure it can fly. if it was a fledgeling it may have gotten trapped before it learned. place it on the ground and make sure it is capable of launching itself up into the trees. once it can do this it will be fine.

Anonymous2015-06-11T12:19:10Z

The bird's history. Go dig a hole. You be cool.

Charles D. M.2015-06-11T12:31:44Z

U can let it go if it is alert and active. If the parents hear it they will continue to care for it.