Layman's version:
Chickens must be kept in a sanitary enclosure at least 25 feet away from any occupied dwelling (other than the owner's dwelling).
 The Urban Chicken ordinance on the books:
Link to municipal code online: Chapter 10.12 Keeping, Care and Control of Animals
10.12.040 Rabbits, domestic fowl, etc.--Enclosure requirements.
It is unlawful for any person to keep on any premises owned, occupied or controlled by him in the City any rabbits, guinea pigs, or any chickens, ducks, pigeons, geese, turkeys or other domestic fowl, unless such fowls or animals are kept in an enclosure, no part of which is within twenty-five feet of any dwelling house occupied by human beings; provided, however, that the dwelling house referred to above does not mean the house in which the person resides who keeps the fowls or animals; provided that any of said fowls or animals may be kept temporarily for purpose of sale at any shop or place of business where the same are bought, sold or dealt in. (Ord. 2533-NS (part), 1942: Ord. 557-NS § 7, 1918)
10.12.050 Rabbits, domestic fowl, etc.--Dyeing or coloring prohibited.
It is unlawful for any person, firm or corporation to dye or color any rabbit, baby chick, duckling or other fowl, or to display, sell, offer for sale, barter or give away any dyed or colored rabbit, baby chick, duckling or other fowl. (Ord. 3806-NS (part), 1961: Ord. 557-NS § 7.1, 1918)
10.12.060 Rabbits, domestic fowl, etc.--Sanitary maintenance of coops or enclosures required.
All coops and enclosures in which any fowls or animals referred to in Section 10.12.040 are kept, must be maintained in a sanitary manner, and be regularly cleaned, in order to prevent any accumulation of manure or offal. (Ord. 2533-NS (part), 1961: Ord. 557-NS § 8, 1918)