The San Mateo County Sheriff's Office learned of the attack Friday morning and responded to a home at 797 Wayside Road, where the goat's owner told deputies the attack occurred at about 9:30 p.m. the previous night, sheriff's Lt. Ray Lunny said.
The owner said she was inside her home when she heard a commotion outside. When she went to investigate, she saw one of her pygmy goats lying on its side in a fenced area of her backyard, Lunny said.
She also saw an estimated 100-pound mountain lion with a long, thick tail pacing in the yard near the injured goat, Lunny said.
The woman screamed at the lion and waved her flashlight at it, and watched as it jumped over the fence and disappeared into a wooded area.
A veterinarian who responded to treat the goat confirmed that its injuries -- two puncture wounds to the neck -- were consistent with a mountain lion attack, Lunny said.
This was the second mountain lion sighting in the area in two days; the first was on Wednesday evening in the 3000 block of Portola Road.
Residents are advised not to approach mountain lions, and try to appear large and make noise if one is nearby. The cats are most active at dawn, dusk and at night.
For more information about mountain lions, visit www.keepmewild.org.