"Leaving your child with a pit bull is like leaving your child alone with a loaded gun," says Jackie David, who works for Los Angeles Animal Control.
Warnings like that struck a chord with some pit bull owners who've started dumping their pets on an already overburdened animal services.
"At one of our shelters our workers have gone in to find pit bulls tied to the fence, or just let loose in the shelter yard," says David.
There have been problems since the introduction of the breed. But 15 years ago there were almost no pit bulls sold in Los Angeles. Now almost half of the estimated 44,000 abandoned or runaway dogs roaming the streets of the city are pit bulls.
Says David: "We have received calls from people held hostage in their homes by dogs, from people held hostage in their cars by dogs."
Animal activists blame dog owners for Southern California's proliferation of vicious and aggressive dogs. More and more people are buying and breeding the pit bull and other guard dogs solely for security, and sometimes even using them in illegal dog fights.
"If you want a guard dog, buy an alarm," says Cinimon Clark, of Pit Bull Rescue. These dogs are not meant to be your alarm. If you neglect them, don't love them properly, if you don't invite them into your home and love them as one of your own - there's going to be problems.
Trying to crack down on problem animal owners, California legislators have introduced a law that would make owning a vicious dog that has attacked a person a felony punishable by up to four years in prison.