Two 2 month old pullets lethargic and unsteady on their feet.

[BettyG]

Good morning, this seems to be fairly sudden onset. I have 5 pullets that I got April 9th, up until now they have been fine, thriving...I noticed yesterday that the little Brahma was a little lethargic, then today the little Spitz. appeared to have trouble staying upright, both of them are still eating, but they kind of lay down by the feeder, I did notice the Brahma's poop was pretty liquidy. Any idea what could be going on? the other 3 seem to be fine so far...