It is unlawful for any person or persons, firm, copartnership or corporation to kill or slaughter or cause to be killed or slaughtered any animal or animals, the flesh of which is intended to be sold or offered for sale, within the city limits, or to keep or cause to be kept any cattle, sheep, swine or other animals, for sale or exchange, or to be shipped or slaughtered, in any yard, pen, corral, stable, structure, enclosure or premises. (1957 code § 4.08.020.)