Animals do not look at the sun for extended periods of time - there are no mass blindness events that happens in the world from solar eclipses.
Is there anything special I need to do to prepare my pets?
Nope, the day can resume as per usual.
Will they be anxious about the eclipse?
No they will not.
What if I'm not at home during the eclipse?
They will be doing what they normally do when you're not around, having a snooze.
"On a normal day your pets don't try to look at the sun and therefore don't damage their eyes, so on this day they're not going to do it, either." - Angela Speck
Rob Warren, a spokesman for the University of California–Davis Veterinary Medical Teaching Hospital, also told The Sacramento Bee that "our ophthalmologists don’t see much need for concern with animals during the eclipse," and that because animals don't look directly at the sun "on normal days," they're not expected to during an eclipse.
(source 1) (Source 2)