actually it's not a dog heaven, but heaven as in our version of heaven... came across this line just dunno who wrote it .. here it goes...
No heaven can heaven be if my dog's ain't there waiting for me

and also came across this... all dogs go to heaven.
I take it you've lost a dog recently... they say the best place to bury a good dog is in the heart of it's owner.
a dog's lifespan is something like 8- 16 years depends on the breed, a man's lifespan is like 60-80yrs. maybe even more... if you own a dog he's bound to die first, you can either stop owning a dog so as not to feel the pain of losing a dog ever again... or you can get another one and another one and so on, and enjoy the time they're with you...just think of this if indeed all dogs go to heaven, just think of all the fun waiting in heaven( that is if u've lost say like 8 dogs

)
here's hoping u'll get another dog