Because when one curates something for a specific purpose, it is sub optimal to use it contrary that purpose. In this case, dogs have specifically been domestic

Because when one curates something for a specific purpose, it is sub optimal to use it contrary that purpose. In this case, dogs have specifically been domesticated to be companions for humans for something like 15,000 years. Humans specifically selected for specific behaviors and traits for dogs for them to be more compatible with humans. In the United States, dogs are used almost exclusively as pets and helper animals. Pigs have never been domesticated in that way in large numbers and have always generally been used as food, or for limited other purposes, occasionally as pets. I think this difference in lineage and purpose leads to a very meaningful distinction.