Today I crushed a dog...
I have heard this several time and I wasn't sure about it.
This is a kind of joke for Chinese people. It means, today I went to the prostitutes!
When you crush a dog with your car, you should pay a compensation around 400rmb to the dog owner. This compensation is about the same as the price of a prostitute.
As you can see it is common in China to speak in metaphor, play on words.