Clallam County Fire District 3 reported to smoke coming out of the building at about 2:50 a.m. Tuesday, July 5.
Peter Loeb, public information officer, said there appeared to be wiring in the ceiling that burned out.
Fire crews extinguished the small fire quickly and used tarps to minimize property damage.
Hospital staff said the smoke stayed out of the main building and went through the roof with minimal damage.
Sequim Animal Hospital is open regular hours, 8 a.m.- 6 p.m. Monday, Wednesday and Friday, and 8 a.m.-5 p.m. Tuesday and Thursday.