Okla. Stat. tit. 4, § 499.9

The provisions of the Dog and Cat Sterilization Act shall not be construed to require the sterilization of dogs and cats which are being held in releasing agencies which might be claimed by their rightful owners; nor shall it be construed to require the sterilization of dogs and cats held pursuant to the provisions of Section 391-402 of Title 4 of the Oklahoma Statutes. Further, the Dog and Cat Sterilization Act shall not be construed to interfere with municipal ordinances that meet or exceed the dog and cat sterilization requirements set forth in the Dog and Cat Sterilization Act.