Riverside County Animal Services said in a statement Tuesday that the incident occurred April 2 near Mecca, the Los Angeles Times reported. The engineer of an approaching train spotted the 10-month-old dog on the track and applied the brakes, stopping in time to avoid hitting the animal.
Union Pacific Agent Sal Pina arrested the 78-year-old man. Pina said the man told him he did not know what to do with the dog since his family did not want it.
"It's probably one of the worst things I've ever seen," Pina said in a statement. "I've never seen something like this."
The man "appeared to be confused or senile and didn't fully understand what he had done," Pina said, explaining why he decided not to pursue a criminal charge of animal cruelty.
A veterinary technician at Coachella Valley Animal Campus in Thousand Palms has been taking care of the puppy, described as "very healthy and friendly." The poodle-terrier mix, nicknamed Banjo for old-style railroad signals, is available for adoption.