What is this?

[Piggiewheekwheek]

Hi all
Can anybody identify this plant?
I can't find it on the safe weeds for Guinea pigs to eat thread.
Is it safe for them to eat?
Thanks

 

[Piggies&buns]

I don’t know what it is, but If in doubt, leave it out

 

[Piggiewheekwheek]

Good job I didn't pick any...its ragwart