Today, the Humane Society of the United States (HSUS) is promoting Spay Day, its 16th annual campaign encouraging guardians to spay and neuter their companion animals. Forty-three countries observe Spay Day, and more than 80 events will be held to raise awareness worldwide. HSUS emphasize the importance of spaying and neutering companion animals by educating the public about problems arising from animal overpopulation. Actress and animal activist Doris Day founded the event, and this year the Doris Day Animal Foundation has donated funding to HSUS to spay and neuter companion animals whose guardians cannot afford the operations. HSUS is also holding an online photo contest to raise money for the animals. Guardians submit cute photos of their companion animals and are entered to win prizes.