Food and Agricultural Code § 31106

The board of supervisors may appoint proper persons to take up, impound, and kill dogs pursuant to this division or it may enter into a contract with any humane society or other organization or association which will do both of the following:

(a) Undertake to carry out the provisions of this division regarding the taking up, impounding, and killing of dogs.

(b) Give a proper bond in whatever amount may be fixed by the board of supervisors for the faithful performance of the contract.