On Thu, 09 Apr 2009 20:11:55 -0700, Jasper Tiler wrote:

How can I teach a dog to stop chasing cats?

Lauralyn already have some good serious advice, so I'm going to take off
on a tangent with a funny about one of my past dobes, Atlas.

Atlas loved to chase cats. He made a big show of chasing and barking,
but he never hurt them. Upon catching up to a cat, he would grab it
around the middle (legs and tail out one end of his mouth, head and more
legs out the other), and bring it to us. Once he'd been acknowledged,
he'd drop the cat and the cat would run off.

Worrying that this was probably traumatizing (or at least really
irritating) the cats, we worked hard with Atlas to teach him to ignore
the cats. When that was finally successful, one cat would run up and
push on whatever part of the dog it could reach with its paws, then run
away. (If the cat could talk, it might have been saying "tag, you're
it!") It seemed to miss the attention!

--Susan