Board Thread:Theories and Speculation/@comment-45444155-20200410191621/@comment-45444155-20200426201450

LegionZero wrote: Most animals have never shown use of chakra/ninjutsu/genjutsu

I dont recall him saying he only gave people chakra. That wouldnt stop people from connecting with animals on their own

Okay, we're done here.

As mentioned above, now in the Naruto universe any living thing has a chakra that is absorbed by God Tree / Shinju. It follows that humans have always had the chakra, but it was only in Hagoromo's time that they learned about its use.