Under a California law, S.B. 762, to take effect January 1, no city or county will be allowed to prohibit a licensed healing arts professional which includes veterinarians from "engaging in any act or performing any procedure that falls within the professionally recognized scope of practice".
California law already prohibits cities and counties from passing ordinances that would prohibit businesses licensed or otherwise authorized by the Dept. of Consumer Affairs from "engaging in that business, occupation, or profession or any portion thereof."  Cal. Bus. & Prof. Code Sec. 460(a). Meaning cities and counties cannot stop pet stores from selling dogs and cats or other animals, for example.
The new law will mean cities and counties cannot stop veterinarians from performing recognized procedures such as declawing or devocalization, for example. After January 1 only a state law can stop such acts.
It is likely this law would not affect the ability of charter cities in California to pass laws limiting or banning cruel veterinary procedures.
The law would not affect local ordinances already in effect prior to January 1, 2010. The law will also not apply to zoning, local licensing or health and safety requirements or limit the city or county’s authority to levy and collect taxes. That means West Hollywood’s ban on declawing, for example, will remain in effect. The ordinance was passed in 2003 and though challenged in court by the California Veterinary Medical Association, was upheld by the appeals court.