I have to say that the calves we butchered had been hand-reared by us, and were individually known ... and named! Having said that they showed no particular affection for us (other than as a supply of buckets of milk) so I had absolutely no compunction. I think a cat/dog which is kept as a companion is a different mater - at least as far as deliberately killing them for food, and by the time it died of starvation there would be little benefit from trying to cook it :-)