It's Flashbeagle, Charlie Brown1984

Charlie Brown:
[to Snoopy, asleep on top of his doghouse] Do you realize what you're becoming? I don't know what you're becoming, but I do know what you're not becoming. You don't do *any* of the things a dog is supposed to do. You don't bark at strangers, you don't bring in the morning paper, you're not even bringing me my slippers at night. In the old days, dogs used to round up sheep, who guard them in case wolves attack. I never see you round up any sheep. I bet you don't even know what one looks like. You don't try to follow me to school, and you don't meet me when I come home. There's nothing worse than owning a dog who isn't a dog.