1922. Vet your pet

Cats are black, white, striped, calico, gray
Dogs, too, come in quite an array
But even if  umber
They're too great in number
Blest be the pet owner who'll spay.

Everyone is familiar with bumper stickers saying 

      I ♥ NY

 I think veterinarians ought to give out ones reading 

      I ♠ my dog