I had a little nondescript dog I called Goofy. I left the DR leaving him with others. When I returned 11 months later I didn't expect him to remember me, but he definitely did.
I left for two years to Saudi Arabia leaving my Labrador with a trusted friend who dearly lover her. When I returned the friend want to keep the dog so I said whoever the dog chooses will be the owner.
She stood on the porch and I to the rent a car door with the door open. She called, and I called and the lab jumped in my car, after two years. They remember quite well. The dog also remembered car rides which she wasn't getting with the friend.