Sunnyvale authorities are on the lookout for a dog hater.

Two boxes of D-Con Mice & Rat Poison were discovered on two occasions in February in the dog area of Las Palmas Park on Russet Drive. The first box had “All Dogs Must Die” scrawled on the yellow box, filled with poisonous pellets that cause internal hemorrhaging.

“That takes it out of the realm of accidental,” Sunnyvale spokesman John Pilger said.

Fortunately, Pilger said no injuries have been reported, but the threat has dog owners fearful and taking extra precautions to keep their basset hounds and Chihuahuas safe from harm.

The city has posted signs alerting parkgoers to be on the lookout for any other boxes of poison or any scattered pellets that might be on the ground. City park workers are taking early-morning walks to patrol the area, and the Department of Public Safety has been alerted to watch the park, Pilger said.

The first box was found Feb. 7 and the second box was found Feb. 26.

Pilger said the city’s crime lab tried to lift fingerprints off the boxes, but none were found.

The boxes show a picture of a mouse zapped dead by what looks like a lightning strike. The pull tabs on the boxes were opened in both cases.

Pilger added that the city was slightly concerned about copycat criminals leaving out poison boxes if they got wind of the news, but decided that alerting the public was the right thing to do.

“God help us if we didn’t do anything,” Pilger said. “We don’t want to have a zapped Rover.”

Authorities asked anyone with information about the source of the poison boxes to call Sunnyvale Animal Control at 408-730-7178.

Contact Lisa Fernandez at 408-920-5002.