A San Pedro homeowner who put up surveillance cameras because he feared a burglar was targeting his house said Friday he was shocked to find a man drugging and sexually assaulting his dog.

The homeowner’s video helped Los Angeles police arrest a suspect who lived nearby.

“It’s inhumane. I don’t even know what to say about it,” said the dog’s owner, who requested anonymity because family members were unaware of what occurred. “I had never even thought of something like that happening. I know his grandmother very well. She has three little dogs.”

Investigators with the Los Angeles Police Department’s animal cruelty task force were not available Friday night, but two Harbor Division detectives confirmed the bestiality report. The dog’s owner identified the suspect as the 22-year-old grandson of one of his neighbors.

Los Angeles police records showed he was arrested Thursday afternoon on suspicion of burglary. He was held at the 77th Street Division jail on $50,000 bail.

In an interview Friday evening, the homeowner said he installed cameras because he found evidence of a prowler in his yard during the past few months. That began in the middle of the night when the family’s 80-pound Akita “made this huge yelp-like shriek like she never made before.”

The dog’s owner said he went outside to check and found a cellphone. Two weeks later, the owner heard the same noise. He found his dog acting oddly and noticed someone had opened a gate.

The resident then installed the cameras. On Sunday morning, he awakened to find fur all over the backyard. He checked the video and watched as the man fed something to his dog, which made her relax after about 15 minutes. He then engaged in sex acts with her for more than two hours, from 2-4 a.m., the resident said.

“He is apparently just a real sicko,” the man said.

The resident took his dog to his veterinarian, where she underwent treatment for sensitivity and returned home to rest.

“I was unhappy I had to put surveillance cameras on my home,” the dog’s owner said. “I’m grateful that I did.”

Before the arrest was made, the dog’s owner warned his neighbors in the 1900 block of Summerland Avenue to be aware of the crime with a posted flier.

“Everybody is freaked out he is going to come back,” the man said.