It is well documented that elephants honor/mourn the dead.

I have been clearly shown several times that dogs understand their own upcoming death. Can't say any more about that, at the moment.

I have seen a mother dog grieve over the grave of two of her pups, although the pups were long past weaning and she really had nothing to do with them.

And I know of at least two dogs that understood that they were about to die. In both cases - and years apart - they were shot by a brother and a brother in law respectively after their owner gave up on their sheep-killing and/or chicken-killing proclivities.

Given all that, I fail to see where I can draw the line as to where and to what they are not able to cogitate and perceive.

It is my own opinion that if there is an afterlife any animal that is capable of loving will survive; and for all I know,the ability to love is not the criterion for their survival. I don't know that much- and I don't know anyone else can claim to.