When I was about nine or ten there was a little stray that adopted me.  Her name was Lady.  She lay on my lap as I waited for the school bus and ran out the road to meet me when I got home.  She showed me where she was having her puppies. 
Sadly Lady died before we had found homes for all 6 of her puppies.  I prayed every night for a full year for God to look after my little Lady.
As a Jehovah's Witness, I can't say I have found scriptural evidence that puppies or any other animal will go to heaven, but I know as a little girl, I had no doubt.
Music of Susan Lawrence