State law regulates the treatment of animals in a variety of contexts.  Animal cruelty statutes prohibit harming or killing animals in most situations and transporting or confining animals in an unsafe manner.  Dog breeding operations are required to limit the number of adult, intact dogs they have at one time, and to meet requirements regarding space, sanitation, and safety.  Only licensed commercial dog breeders who were licensed by the United States Department of Agriculture (USDA) prior to January 1, 2010, are allowed to have more than 50 intact dogs over the age of 6 months at one time.  Some local governments also impose regulations on the sale of animals intended for use as pets.  Examples of local regulations include imposing licensing requirements on retail pet stores and prohibiting the sale of animals in public places.  In 2021 legislation passed that prohibited retail pet stores from selling cats, and only retail pet stores selling dogs prior to July 25, 2021, could continue to sell dogs.

An "animal care and control agency" means any city or county animal control agency or authority authorized to enforce city or county ordinances regulating the care, control, licensing, or treatment of animals.  An "animal rescue group" means a nonprofit organization that has a primary purpose of preventing the abuse, neglect, cruelty, exploitation, or homelessness of animals, and exclusively obtains dogs, cats, or other animals for placement that are:

• stray or abandoned;
• surrendered or relinquished by animal owners or caretakers;
• transferred from other animal rescue organizations; or
• born in the care of such nonprofit organization, other than through intentional breeding by the nonprofit organization.

The state prohibits a live dog or cat from being named as collateral for a consumer lease, retail installment transaction, or consumer loan.

A retail pet store that sold or offered for sale any dog prior to July 25, 2021, may sell or offer for sale a dog only if the following conditions are met:

• the dog is sold or offered for sale only at the address identified on the retail pet store's business license;
• dogs sold or offered for sale are obtained either directly from:  (1) breeders, including out-of-state breeders, that meet the requirements of Washington's breeding laws; or (2) United States Department of Agriculture (USDA)–licensed brokers who obtain dogs from breeders who meet Washington's breeding laws;
• a dog must possess documentation obtained from its breeder demonstrating that the dog was not separated from its mother prior to the age of eight weeks, and the breeder's compliance with Washington's breeder laws on the date the dog was obtained from the breeder;
• retail pet stores must, prior to obtaining a dog from a breeder or broker, obtain all USDA inspection reports for the breeder within the previous three years, if applicable, and maintain and, upon request, produce the records for a period of five years following the sale of a dog;
• retail pet stores must include on advertisements offering to sell a dog the range of prices at which a dog, breed of dog, or dogs having other distinguishing traits are offered for sale; the age of the dog; and supporting documentation providing the applicable federal or state license numbers for the dog breeder, if applicable;
• retail pet stores must post the dog's purchase price, age, and the breeder's name, kennel name, city and state, and applicable state or federal license numbers; and
• retail pet stores must disclose to a prospective consumer, in writing prior to a sale, the dog's purchase price, applicable federal or state license numbers, and an unredacted list of all violations of any federal or state law the dog breeder received in the previous two years on a federal or state inspection report.

For retail pet stores that provide space and care for adoptable animals owned by animal care and control agencies or animal rescue groups, the retail pet store must display for each dog or cat a label stating the name and address of the animal care and control agency or animal rescue group.

A retail pet store that violates these requirements is subject to a class 1 civil infraction of $250.  A retail pet store that has more than three violations in a one-year period is prohibited from selling or offering to sell any dog. Enforcement officers and animal control officers may investigate and enforce the regulations for retail pet stores.

A person is prohibited from having more than 50 intact dogs over the age of 6 months at any time, regardless of whether the person was a USDA-licensed commercial dog breeder before January 1, 2010.

Any consumer lease, retail installment transaction, or consumer loan entered into for the purchase of a dog is void and unenforceable, and the lessor, retail seller, or licensee has no right to collect, receive, or retain any principal, interest, or charges related to the lease, retail installment transaction, or loan.