Poisonous mushrooms???

[Melissa2173]

So about a week ago, I came home to one of my silkies dying. She passed within an hour. Came home Friday to another silkie lethargic and showing neurologic symptoms. She can't walk, when she tries she goes backwards. Her right leg and wing are affected. She tries to eat but it's not enough so I'm crop feeding her. I've had mushrooms popping up in my yard. Only thing I can think of that they may have gotten into. Anyone have experience with this?

 

[Fanci Feathers Marans]

A picture would help. If they are the kind I am thinking of- small, white caps that grow on mouldy hay- then they are probably harmless. Check for bite marks, too.
Take this with a grain of salt, but it sounds like a stroke. Do birds have strokes? I don't know, but I know it affects one side of the body or the other.