The first border collie arrived at the Pasadena Humane Society two weeks ago. She was found roaming the upscale neighborhood surrounding Cal Tech, sweet-faced and pregnant.
Not long after, two more collies appeared, this time wandering Hasting Ranch. These, too, were days from giving birth.
In total, the three dogs produced 14 puppies.
Animal Control officials believe that one person may be responsible for dumping the dogs throughout the city. The three border collie mixes are around 1 year old and have similar coloring and facial features, said Jamie Holeman, a spokeswoman with the Pasadena Humane Society.
Now, police are searching for the person who left the dogs to fend for themselves on Pasadena streets, which is a misdemeanor offense.
"The dogs were probably more than they could handle," said James Chisum, a spokesman for the Pasadena Humane Society. But there are more humane ways to relinquish animals, he said.
Unwanted dogs can be left at the local shelter or given to willing family members, Holeman said. They can become a danger to themselves or motorists if they are dumped in neighborhoods.
The collies were rescued, and all of them were found foster homes.