-------------------
literal translation
-------------------
Wagging tail
my puppy
it is I who should thank you.
----------------
(Eigo 3-5-3) versions

----------------
Wagging tail
canine faithful friend
my thanks, too.

----------------
Wagging tail
velvet faithful friend
my thanks, too.

----------------
Wagging tail
wonder doggie friend
my thanks, too.

----------------
Wagging tail
and welcoming eyes
home at last !

----------------
Wagging tail
and welcoming bark
home at last !

----------------------------------------
thanks to a friend for help with first line in nihongo,
I hope you can get a "koinu" soon.