I live in West Sacramento, which is in Yolo County, NOT in Sacramento/Sacramento County, thank goodness.
We CAN have chickens, if the property is large enough. The City of West Sacramento contracts with Yolo County for animal control services. The zoning restriction considers chickens as "livestock" and there's a formula for how many/what kind of livestock can be maintained on what size lots. It's referred to as Animal Density Points, and an acre can have 25 points. Each chicken is worth one point. However, my landlady lives on the same acre where I rent (in the front house) and she keeps 3 sheep. Each sheep is 4 Animal Density Points. Therefore, she's using 12 of the 25 ADP for the property and I "can" have 13 chickens. ("Immature offspring not yet sexually mature have NO points at all and are not counted.")
I am currently under the legal limit, but I have enough "immature offspring not yet sexually mature" that WILL take me over my limit before too long.