Pit bulls kill toddler; pit bulls are killed. A sad, familiar story.

There was another troubling and tragic story this week of pit bulls killing someone in Southern California. In this case, it was a 2-year-old in Colton who slipped into the backyard of his grandmother’s home where her five pit bull mixes were kept. Samuel Zamudio’s clothes had been torn off when his 42-year-old grandmother, Eustalia Zamudio, found him in the backyard. He was rushed to a hospital, where he was pronounced dead.

The death of the toddler follows a fatal mauling last May of a jogger who was attacked on a street in the Antelope Valley community of Littlerock by several pit bulls that got out of their home.

Any death -- or serious injury -- by a pit bull, or any dog, is one too many. In the Antelope Valley incident, there had been previous complaints about the dogs -- they had attacked other animals -- and the dog owner was arraigned on charges of murder and animal negligence.

In the case of Zamudio, both the grandmother, who owned the dogs, and the toddler’s uncle, who was supposed to be looking after him, were arrested Monday, the day of the attack, on suspicion of child endangerment resulting in death.

Although this case is still under investigation, there are some disturbing reports about these dogs. One neighbor had complained to animal control authorities about the loudness of the dogs and the stench from the yard where they were kept. Another neighbor, according to a report in the Los Angeles Times, said the dogs seemed restless and starved for attention. It’s unclear how long on Monday or how often the dogs were kept in the backyard. But simply leaving dogs for hours on end in a yard by themselves -- particularly dogs that can be aggressive to other dogs and to people -- is no way to socialize or enrich them.

The dogs, which were confiscated by authorities and taken to a San Bernardino County animal shelter, have been euthanized. As they should be.

But I’ve said this before and I’ll say it again -- a mauling by a pit bull is not an indictment of all pit bulls.

I’m not an apologist for pit bulls. I’m a proponent of conscientious and responsible dog ownership. And when it comes to owning pit bulls, people must be particularly vigilant and devoted to their care and nurturing. And if they can’t do that, they shouldn’t own pit bulls.

If there turns out to be compelling evidence that the owner of these pit bulls was irresponsible, the penalty should be severe.

In the wake of the Antelope Valley mauling, the Los Angeles County Board of Supervisors tightened up regulations on vicious dogs. That was smart. In Riverside County, there is a proposal to require all pit bulls in unincorporated cities to be sterilized. Also smart. In fact, they should require that for all pet dogs. In the city of Los Angeles, all dogs and cats -- with some exceptions -- must be spayed or neutered.

Let’s insist that pit bull owners be exemplary in the care of their dogs.

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