Apparently California has a LAW stating that if you buy cat/dog blood, that purchased blood HAS TO come from a closed-colony blood donor.
A closed-colony blood donor is a cat or dog who live in these closed colonies and are 'bled' every couple of weeks.
Only in 2022 were California vets allowed to operate a pet blood bank with donor blood. However, they are not able to compensate the owners whatsoever. Even giving a bandana saying 'I donate blood' was not allowed.
Vets got around this by offering owners free vet services, such as vaccines and exams, which are commonly required prior to a blood donation.
The current wait time for donor pet blood is between 9-24 weeks. Most vet offices will use employee pets as blood donors. Blood shortages pose a real problem for pet owners, and can often be the determining outcome for particular patients.