For one thing, they shed and make your clothes and personal spaces look disgusting. They also try to interact with you and touch you without your consent. Dogs are animals. They belong outside, not in shared people spaces.
Though much has been discussed on the topic, I consider down votes to be for those comments that don't contribute to the discussion, even if I might agree. In your case, however, I not only disagree, I don't feel your comment has contributed positively to the discussion. Whereas the parent comment did bring a different viewpoint to the discussion, though I might disagree with them.
In conclusion, have a down vote. Parent: have an upvote.
I'm happy with that. I was just kvetching really (and I didn't actually downvote). I strongly feel that votes should be used as you statrd., and not in lieu of a reply expressing disagreement through the courtesy of a reply. my complaint really is that downvoting is so capricious. people who hate dogs in the office downvoted me for saying that dogs have not been a problem at my office. the statement was factual, respectful and related. meanwhile I can say some snarky thing and get upvoted like crazy. it's just silly