It would be best to keep all pets indoors during the eclipse. I really don't think wild animals will intentionally look at the sun, they're much smarter than that on ANY day.
Upcoming solar eclipse : Does this mean we can expect wildlife and pets to have a risk of vision problems?
I don't think it will hurt them. But, the chickens will go nuts this afternoon when it gets dark.
Animals don't generally look at the sun. The eclipse to them will be more like a big storm cloud coming through without the nasty weather. The light changes at sunrise and sunset signally the start and end of a day for animals. They won't have that with the eclipse so they are not going to think it is night. The animals will be fine. It is only us humans that make a big deal out of it and dumb enough to look at the sun.