Under most neuroscientific theories, suffering is not just about detecting damaging stimuli, but requires integrating multiple streams of information into a unified evaluative model that links sensation, memory, affect and motivation.
You, as a human, associate injury with negative valence. That does not mean shrimp do.
All is here. The debate is not about the numbers but about the definitions. Suffering in more complex animals plausibly evolved out of mere damage detection. Is it different? Admittedly. But the difference lies along a continuum. No lizard ever woke up one morning as a mammal, suddenly capable of suffering, while its father merely detected damage. Reality is not black and white, it is shades of gray. Remember Yudkowsky’s old post “0 and 1 are not probabilities”.
In the present case, I am not defending shrimp, and the arguments are persuasive, my impression, however, is that the priors are doing most of the work in this discussion. The disagreement is more about priors concerning the gradation nociception ⇒ suffering than anything else. It’s really difficult to decide.
Ok, but 1) I won’t say that Nature or the dogs do something moral or immoral. The moral agent that takes a decision to act or not does something moral or immoral.
And 2) the moral agent’s action is moral or immoral regardless of the fact that dogs and wolves have been fighting in nature for millions of years. That fact is neither a mitigating nor an aggravating circumstance for the moral agent. It is neutral, the agent bears no responsibility for the state of nature.