Such abuse ought not be allowed.
1. It is a highly vicarious means of redirecting angst and rage at foids but doing so in a manner which gives no consideration to how attenuated the relationship is between the justifiable object of the hatred (foids) and the most readily available and proximate easy target (dogs)
2. You could conceivably make the argument about any animal whose aesthetic appeal or cute countenance may resonate with the sensibilities of most mindless and frivolous whores who sentimentalize everything. This principle could logically be extended to include babies or young children also since they likewise serve similar function vis-à-vis foids.
3. Dogs are intrinsically decent and honorable creatures. While we do anthropomorphize them to an extent, they seem to embody the most noble of human virtues which include loyalty, respect, obedience, courage and service to their masters. By permitting such imagery we are only encouraging people to construe dogs in an unnatural manner - e.g., as being primarily concerned with the inequitable allocation of sex in our culture.
4. Images of torture, dismemberment, death, etc. appeal to the prurient and most base qualities in us and thereby promoting or tolerating them is a debasement of us and is a form of intellectual and cultural degeneracy.