In Animal Fantasy, animals have human characteristics.
Talking Animals in Folktales often talk with human beings or with each other.
Nonfiction/Science Books are stories about animals in their habitats.
Realistic Fiction Animal Stories are books where animals and humans have relationships where the main character usually goes through a life-changing event or growing experience.
"What is Real?" asked the Rabbit one day.
"Real isn't how you are made," said the Skin Horse. "It's a thing that happens to you. When a child loves you for a long time... then you become Real."
~The Velveteen Rabbit by Margery Williams
Animal Tales are stories that involve animals and will likely fall into more than one genre category.