Question

What does it mean when dogs ears go back?

Answer 1

The Ears: When your dog's ears are forward, it means the dog is paying close attention to something, or is curious.

When your dog's ears are flat against its head, it represents fear or aggression.

Ears way back but not close to its head may mean that your dog is feeling sad.

Answer 2

When the ears are tilted back, the dog is usually stressed or fearful and may be in a submissive state. But  caution here  a dog holding its ears back could also become fear aggressive.