Furious that his girlfriend had broken up with him and stopped taking his calls, Steven Butcher decided to take his anger out on the couple's small puppy.

"Every time you . . . don't pick up the phone, I am beating the dog," Butcher said in an angry voice-mail message he left for his ex-girlfriend. In a later message, as the dog yelped and cried in the background, he said: "You got some more of the dog getting beat."

When police officers arrived at Butcher's Reseda home, they found Nelia, the pit bull puppy, shivering in a sink with cold water running over her. The animal's jaw had been broken, her eye sockets had been fractured and several of her ribs had been cracked.

Butcher, 23, was charged and convicted last year of animal cruelty -- one of a growing number of serious animal abuse cases in Los Angeles, where police and prosecutors say they are taking crimes against animals more seriously than ever.

The Los Angeles Police Department has devoted five officers and detectives to a task force dedicated to investigating animal abuse and neglect. The county district attorney's office recently began training a select group of prosecutors to handle animal-related cases and is seeking tougher sentences for repeat offenders.

Los Angeles has become a national model for its stepped-up enforcement of animal cruelty laws, animal welfare experts said.

The efforts by L.A. authorities and others throughout the country have been propelled by a growing public disgust for such abuse and mounting evidence of a link between animal cruelty and other types of crime.

"As a society, we're just less tolerant of unnecessary and unjustified cruelty to animals," said Dale Bartlett, deputy manager of the animal cruelty and fighting campaign at the Humane Society of the United States.

In Los Angeles County, records show that during the 12 months that ended in August, the district attorney's office filed animal cruelty charges in 116 cases, nearly 50% more than in the previous year.

Last year, prosecutors won a rare dogfighting trial against a 42-year-old nurse, who was sentenced to three years in prison. And in a separate case, the first person they had ever charged with a felony for cockfighting was convicted.

Randall Lockwood, an expert on animal abuse and a senior vice president at the American Society for the Prevention of Cruelty to Animals, said Los Angeles had adopted one of "the more progressive approaches" in the nation in dealing with crimes against animals.

"It's something that's needed in more major cities," he said.

The Los Angeles City Council created the Animal Cruelty Task Force in 2005, following a proposal by Councilman Tony Cardenas. In backing the measure, LAPD officials cited studies finding that animal abusers were often involved in other crimes such as drug trafficking, child abuse and domestic violence.

Task force detectives said they have seen the connection for themselves.

In the case of Nelia, the beaten puppy, police said her owner also threatened to kill his girlfriend during some of his phone calls. He was sentenced last year to 270 days in jail for animal cruelty, placed on five years' probation and ordered to undergo counseling. The puppy survived and was adopted out when authorities suspected that Butcher's ex-girlfriend might reconcile with him, police said.

The task force investigates nearly 300 reports of animal abuse and neglect each year. Its successes include 57 arrests for cockfighting and several arrests for deadly violence against animals.

In 2006, LAPD officers stopped Gene Speer when they noticed him walking along a Hollywood side street with blood all over his shirt. Speer was carrying a backpack. When officers looked in the bag, they found a dead rat terrier that belonged to his roommate.

Speer, 34, told police that the dog, Nehi, had bitten him and he had struck out in self-defense. But LAPD Det. Susan Brumagin, a member of the task force, said officers found animal feces on the carpet and believed that Speer beat the dog to death with a shoe after the animal defecated. He was sentenced to 16 months in prison.

"None of the people we arrest think they could go to prison for hurting a dog or a cat," Brumagin said. "They don't show remorse. . . . They're more shocked and surprised."