Leviticus 11:27

Clearly, dogs have paws, it goes on four feet, and so it is unclean. So another strike against the dog there. It is unclean. That eliminates both dogs and pigs from being sources of food for us. Both dogs and pigs are carrion-eating scavengers. Remember I said earlier, they will both pretty much eat anything and they will enjoy it. That is why God made them. They are made to take decaying matter, garbage of all kinds, and turn it into what they defecate and which actually is organic and can actually help us grow things in the soil. So they have a good purpose in that regard.

They will also both eat human flesh, which makes them especially unclean, if you want to think of it that way. Remember, Jezebel was thrown from the window and dogs came and ate her flesh. So that is another big strike against them. Unclean animals, birds, fish, insects are all called both abominations, you can see that in Leviticus 11, verse 10, and some of the verses after that, and in Deuteronomy 14:3 they are called detestable. So they are abominable and detestable in God's sight in terms of food. They are to be considered unclean and a lot of that too has to do with they are carriers of disease as well, which our immune systems have a hard time fighting against. So the admonitions there not to touch their dead bodies is there for our good. And it does also say here that they will be unclean until the evening. That is to keep us away from other people so we do not spread it.