According to a survey by the American Animal Hosptial Association, 73% of pet owners would go into debt in order to provide for their pet’s well being. Other findings:

20% include their pet in their will
62% celebrate their pet’s birthday. (Of that 62%, 51% sang “Happy Birthday.”)
52% include news about their pet or a photo of their pet in a holiday card
67% said they felt guilty leaving their pet home alone
47% said that when they leave their pet alone they leave on a TV or radio

–Source: AKC Family Dog Magazine