(For the sake of simplicity, I'm going to assume you mean anthropomorphic animals specifically - forgive me if I'm mistaken in my assumption)
I believe that anthropomorphism can still be found in children's literature. Just look to Brian Jacque's famous Redwallseries.
If there is a decline in anthropomorphic books, it may be due to a few factors:
It might be seen as old fashioned now. Who knows? Remember that every book has to be cleared by a publisher. The publishers may feel that childrens' books with animal characters are no longer "original" or interesting. They may think it's old news.
Some other modern popular books and series that contain anthropomorphism are:
There are also many classic books that are still hugely popular, and quite accepted.
Example sentence(s) - Childrens books are usually illustrated. I enjoy reading the childrens books to them.
Puffin Books.
Childrens books
childrens books
he did write both
Nancy Drew books are children's books.
Richard Scarry
Author and editor of childrens books.
He is an author who writes childrens books
Writting Childrens Books!
freddy jason
it only reads in childrens books