You have crashed!

Countersteering is not your first move even if the dog is almost under your wheels.

In a crash situation you always want to have TWO crashees trying to avoid impact. Hitting the horn will alert the dog to your presence and IT will also try to avoid impact. This is usually all that is needed.

If you try to countersteer to avoid the dog, you may clip the dog when you are angled over and you will almost certainly go down.