I absolutely love dogs, but my father taught me long ago, if you don't have a good option, hit the dog (or other animal). This could have been a whole lot worse for you or others around you. I know you don't have much time to think in situations like that, but wrecking is usually going to be far worse than hitting a dog. I had to take out a dog once or risk hitting another car on my right at about 50 MPH. I did what I had to do, but I wasn't happy about it.
My mom nearly killed me and my 5 siblings trying to avoid a dog in the road when I was a kid. We wrecked and ended up about 10 feet from a 150 ft. drop into a valley. My dad wasn't there, but when he found out it was over a dog.... man, he was not happy.