The calf, apparently spooked by the dog, ran into a fence at the buffalo paddock in Golden Gate Park and broke three ribs, the Los Angeles Times reported Thursday.
The dead calf was one of seven being quarantined at the historic buffalo facility operated by the San Francisco Zoo and the city recreation department.
The dog, described only as a small, toy breed, was with a handler but was running off-leash, zoo spokeswoman Lora LaMarca said.
The dog handler was cited for having dogs off-leash in a designated on-leash area and for animal disturbance, the zoo said.
The bison herd has been a popular attraction at Golden Gate Park since 1877.
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