Do you have to pay for the dogs?

Here's, as per SF SPCA website, the fees for adopting a dog : Standard Dog Adoption Fees$175 dogs* $350 puppy adoptions for people who have not attended our free Puppy Parent Orientation class (puppies under 6 months)*50 percent OFF puppy adoptions for people who have attended our free Puppy Parent Orientation class (puppies under six months, $175)* Additional discounts may be offered for cats or dogs who arrived as bonded pairs. Double the love and inquire at the adoption desk for more information! *At the time of adoption, San Francisco residents pay a $23 San Francisco dog license fee.

There is adoption fee and a $26 licensing fee if you live in San Francisco. The shelter is a non-profit so it's technically a "donation" and all the money goes right back into the shelter.