Mason County, WA Animal Ordinances: Breed Restrictions (2026)

Mason County Code § 4.08.020 defines a 'dangerous dog' as one that, per the appropriate authority's records, has inflicted severe injury on a person without provocation, killed a domestic animal off the owner's property without provocation, or was previously found potentially dangerous and again aggressively bites or attacks. A 'potentially dangerous dog' is one that unprovoked bites a person or domestic animal, chases or approaches a person in a menacing fashion off the owner's property, or has a known propensity to attack or threaten. Nothing in this definition turns on the dog's breed; the finding is behavior-based, made by the animal control authority under MCC 4.08.060(a) and 4.08.070(a) on a citizen complaint, a bite report, an officer's observation, or other evidence, with written notice to the owner and a right to a district court hearing within five days.

Once declared, MCC 4.08.080(a) makes it unlawful for the owner of a potentially dangerous dog to let it be at large at any time, and a dangerous dog must stay muzzled and under physical restraint whenever it is outside its proper enclosure, or face a $250 civil penalty per violation under subsection (e). The stakes rise sharply for a repeat offender: under MCC 4.08.080(g), if a dog whose owner has a prior conviction under this chapter attacks or bites a person or another domestic animal, the owner is guilty of a Class C felony under RCW 9A.20.021, and the dog is confiscated, quarantined, and humanely destroyed.