In any district the establishment, maintenance or operation for compensation of small animal hospitals, clinics, boarding stables, dog kennels or similar facilities for the housing, boarding, service, treatment, care, breeding or sale of animals or fowl, and the keeping, feeding, breeding and production of rabbits or poultry for sale either alive or dressed or for the sale of eggs, is prohibited. This prohibition shall not include the housing, care, service, breeding and sale of animals or fowl, or animal or fowl products, which are a part of a farm operation, nor shall it include the establishment and operation of small animal hospitals and clinics in the B Business Use Districts, as provided in this chapter.