My cat and dog have lived together nearly a year now.
They "play" all the time like this. You would think they are killing each other.
She (Suede the cat) waits under the table for him (Kurt the dog) to walk by and pounces.
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I filmed a couple videos of their craziness...
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A friend of mine had a Italian greyhound/chihuahua mix (Luna) that plays with his cats like that all the time. When Luna came to visit me, she tried to play like that with Isabella. After awhile, I was all "where's Luna?" She was cowering in the corner of the kitchen with Isabella sitting in the doorway nonchalantly licking her paws.
*smooches*
Awwwww......... precious!