Well since I myself don't own a pup. I'll post some nicknames I have for friends dogs.

Buddy:
Bud
Butty
Buttley
Budsy Boy
Boo Boo

Amber:
Ambs
Ambert
Ambie
Bambi
Ambie Wambie

Digger:
Dig
Diggy Dog

Pepper:
Pep
Peppy
Pepsi

Bambi:
Bam
Bumble Bee
Bumble Yam (hehe)
Bumba