Until "Mama" moved into Tony Guzman's laundry room, he was lukewarm to Chihuahuas.

"Personally, I'm not a fan of the breed. … Mama's really calm and sweet, though, so she grew on me," he said.

The Guzmans recently found Mama (and one of her puppies) huddled on the lawn of their Galt home. They couldn't bring themselves to shoo away the frightened-looking Chihuahuas.

No one has come forward to ask for their return.

Animal control agencies and humane organizations throughout California say stray Chihuahuas like Mama are competing with pit bulls for boarding space, despite their teensy size.

Guzman said he's found a home for the puppy, but Mama, not much older than a puppy herself, still is looking for a permanent home.

"She's a lot to be responsible for, but I'd rather not see her put down or sent back on the streets," Guzman said.

Daniel Torres, Sacramento's head animal control officer, said the city shelter is packed with Chihuahuas, the result of purchases gone awry and also "backyard breeders" who dump their excess litters before they can mature.

On a visit to the shelter last week, half the kennels on the adoption floor were occupied by at least one Chihuahua – or a Chihuahua mix.

Torres said he rarely gets calls complaining of violent Chihuahuas; most calls are from exasperated owners.

"People buy the Chihuahuas because they're so doggone cute, but they don't have the greatest disposition around kids," Torres said. "A small dog has to protect itself."

Gina Knepp, the shelter's spokeswoman, faulted a "Paris Hilton effect" for adding dramatically to the intake of Chihuahuas.

"We go through cycles of breed popularity, and we're still in the Chihuahua phase," Knepp said. "It's a very fashion-driven trend."

Much as the "Legally Blonde" movies and Taco Bell commercials have raised interest in Chihuahuas, Knepp said the 1990s saw a similar spike in dalmatians ("101 Dalmatians"), golden retrievers ("Air Bud"), and pot-bellied pigs (George Clooney famously had one).

Lesley Kirrene, spokeswoman for the Sacramento SPCA, said that between 2006 and 2010 the volume of Chihuahuas more than tripled at the shelter. Out of 6,546 dogs processed last year, 963 of them were Chihuahuas, second only to the 1,381 pitbulls that came in.

"If there's an increase in the general public, there will be an increase in the shelters too," Kirrene said. "Some of the Chihuahuas will be unable to fulfill expectations."

The Sacramento SPCA has "had success placing the small dogs," according to Kirrene. She said Chihuahuas periodically are transferred from the overburdened branches into Sacramento's.

Last summer, for example, the Sacramento SPCA reclaimed 104 dogs under the care of Kimi Peck, a screenwriter who used to run Chihuahua Rescue in Kern County.

"Between 1999 and 2010, I saved at least 5,000 Chihuahuas from being killed – and I had all of them neutered or spayed," Peck said in a phone interview.

Other canine rescue groups, such as A Leg Up Rescue in Petaluma, work directly with overcrowded shelters to place Chihuahuas in foster homes, pending their adoption.

Jennifer Bird, founder of A Leg Up Rescue, said that 40 to 50 households in Northern California have volunteered so far through her nonprofit.

"We have some good relationships with the shelters, and they'll know which organization to call for which breed," Bird said.

A Leg Up Rescue is receiving so many calls, according to Bird, that she has had to refuse amnesty for the first time.

She focuses on small dogs because they are less socialized and more sensitive to the hubbub in shelters – which can bring out aggressive defense mechanisms.

"Imagine living with your ear practically to the floor, inside an apartment much of the time. That's the perspective these Chihuahuas have," Bird said.

One of her volunteers is Chuck Sheldon, a lawyer in San Francisco whose father was a veterinarian.

He described the apparent overbreeding of Chihuahuas as "a human-created problem, a sad state of affairs."

Guzman suspects Mama was part of a puppy mill. He took her to a veterinary clinic for shots and a spaying. Nothing is wrong with her health, he said, but the dog's teats are extremely slack and low-hanging.

"It seems like (her previous owners) were breeding her like crazy," Guzman said.

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