I was wondering how long before that dirty little word would pop up!
Frankly I am quite the fan of Goodall and Grandin. Though I harbor no ideas on reptile emotion -- their brains really are quite different -- but there are some pretty good reads out there.
The emotional lives of animals - Bekoff
The souls of animals - Kowalski
When Elephants weep - Masson
-just to name a few.