California pet hospitals rely heavily on **blood from closed colonies**, where dogs are kept as full-time donors.
Despite a move towards **community blood banks**, closed colonies provide over **97% of canine blood products** in the state.
State regulations introduced in 2021 aimed to phase out closed colonies, deeming them inhumane, yet implementation has been slow.
Animal welfare advocates express concerns over the **conditions of donor dogs**, with no regulations on donor duration or required transparency in operations.
The **veterinary community** faces a critical blood supply shortage, complicating efforts to switch to a more humane donation model.