How far up the evolutionary tree do you believe suffering extends? Primates? Mammals? Vertebrates? Any animal with a nervous system? What about plant suffering? Does an overworked computer suffer as it frantically swaps memory between RAM and disk? Are you sure you're not committing the mind projection fallacy.

Also, while we're on the subject why should suffering be the basis of morality, as opposed to something like subjective experience?

This is another case where, it seems to me, rather tortured reasoning is required to argue that other animals aren't really suffering even when we have every reason to think they are.

I suspect your definition of "tortured reasoning" amounts to any complex reasoning that leads to conclusions you don't like.