California Code, Civil Code - CIV § 4715

(a) No governing documents shall prohibit the owner of a separate interest within a common interest development from keeping at least one pet within the common interest development, subject to reasonable rules and regulations of the association.  This section may not be construed to affect any other rights provided by law to an owner of a separate interest to keep a pet within the development.

(b) For purposes of this section, “pet” means any domesticated bird, cat, dog, aquatic animal kept within an aquarium, or other animal as agreed to between the association and the homeowner.

(c) If the association implements a rule or regulation restricting the number of pets an owner may keep, the new rule or regulation shall not apply to prohibit an owner from continuing to keep any pet that the owner currently keeps in the owner's separate interest if the pet otherwise conforms with the previous rules or regulations relating to pets.

(d) For the purposes of this section, “governing documents” shall include, but are not limited to, the conditions, covenants, and restrictions of the common interest development, and the bylaws, rules, and regulations of the association.

(e) This section shall become operative on January 1, 2001   1, and shall only apply to governing documents entered into, amended, or otherwise modified on or after that date.