If a living being is not self aware than can he experience suffering or pleasure? When some living being like dog or any mini bacteria are killed, since they are not self aware or concious do they feel the same type of pain as we do? what is the difference between their suffering and our suffering?
Dogs don't forget pain. You only have to look at a dog that has been continuously beaten and then cringes or tries to bite anyone who tries to pet it.  Yes it has become an automatic reaction but there must be some kind of memory there about humans not being trustworthy.