Some cat lovers are pretty strange.
In "Prehistory of the Far Side", Larson said that he thought that what bothered people about the cartoon was that there was no escape for the cat. In a typical animated cartoon, if a cat is run over or blown up, a few seconds later he has recovered and is back in action:
There's never a suggestion that the cat's suffering is anything but transitory. In a single panel cartoon, however, no resolution is possible. The dogs play 'tethercat' forever....I suppose some people may have appreciated a disclaimer at the bottom of the cartoon saying, 'Note: A few minutes later, the cat escaped, returned with a bazooka and blew the dogs away.' (Of course, now I'm on the dogs' case.)
Larson was great.