Anti-freeze will kill anything that drinks it. That being said, it does good work on a dog in hot weather.
We finally nailed a crafty feral tom cat that was hanging around the house and beating up our young tom, eating his food and then putting the end product on our deck. No females around. I trapped him 3 weeks ago and drove 3.5 miles and dropped him off. He still came back just to try and finish off our tom. Took 3 shots with .22 to put him out...tough little bugger. I got no sympathy for pets gone bad.