Dogs/wolfs die by falling through blocks

Put the summary of the bug you're having here
Dogs/wolfs die by falling through blocks

What I expected to happen was...:
they should not die

What actually happened was...:
they fell through the block they were standing on and died of suffocation (primarily, wooden planks)

Steps to Reproduce:
1. spawn wolf/dog
2. i don't know if they fall through all blocks, but the block it was mostly falling through were wooden planks
3. wait and watch