Said goodbye to the dog (4)
I believe the answer is:
chow
'to the dog' is the definition.
(short for chow chow)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for chow that I've seen before include "Long-haired Chinese dog or slangy food" , "Grub" , "Long-haired dog of Chinese breed, or informal food" , "breakfast?" , "[HOUND]" .)