The University of California at Davis has launched a dog blood-donor program . That's dog-to-dog of course. Some die-hard owners would no doubt be willing to open a vein for their favorite pet, but that service isn't available yet.
And if you're wondering, according to the UC Davis press release, dogs, unlike humans, have 13 blood types, the preferred donor type being dog erythrocyte antigen 1.1 negative. I guess you'd have to drive to Davis to find out whether or not your pet is a universal donor.
Unfortunately, if you're interested in having your pooch donate blood, you're out of luck. Davis might be in the same congressional district as we are, but the blood bank is only looking for dogs within a one hundred mile radius of the vet school. You'll have to wait until they establish a mobile blood bank, which -- by the way -- is already being considered.
photo from The Age (Australia)