A security guard found the dog Wednesday on the campus of La Sierra University in Riverside, the Los Angeles Times reported. Investigators are unsure if the dog was hurt elsewhere and dragged itself to the campus or if it was shot there.
The puppy, which had no identification and appeared to be about 6 months old, had an arrow piercing its side.
Veterinarians at the Western Riverside County/City Animal Shelter tried to treat the puppy, giving it antibiotics and pain medication. They decided the only humane course was euthanasia.
"He was bleeding from his nose, and he was having difficulty breathing," Eileen Sanders, a veterinary technician and spokeswoman, said. "His right-side lung was either filled with blood or had collapsed."
The ASK Foundation, an animal advocacy group that works with the shelter, has offered a $500 reward for information leading to the shooter.
"We're a big organization. We come across some heinous things," Riverside County Animal Services spokesman John Welsh said Thursday. "But this is one of the ones that really make you shake your head. It's malicious and disgusting."