The Shulchan Oruch 79:4 groups dog excrement together with pig excrement, and the Be’er Heitev says ‘Cursed is the Jew who grows pigs’
The Mishna Berura is more meikel, grouping a BAD dog together with pigs
Also, in Halacha, we know the concept of ‘water that is not drinkable by the standards of a dog’ for water that is posul or kosher for netilas yadayim