Humans aren't the only victims of the mortgage meltdown. The credit crisis is also taking its toll on horses, llamas, chickens, dogs, cats, alligators and the occasional iguana.

As families lose their homes to foreclosure, man's best friend and his fellow pets are being surrendered to shelters, abandoned on the streets or even left to starve in locked-up houses, according to animal welfare organizations around the country.

In Arkansas, Cheryl Lang, a foreclosed-property inspector, found three dogs left locked in pet carriers in the back yard of a foreclosed home. Abandoned without food or water, the animals had died.

Another dog that was left in a back yard of a foreclosed home in Jamaica, N.Y., met the same fate.

Lang, who has founded No Paws Left Behind, an organization that assists animals that have been deserted by their owners after foreclosure, said she has seen llamas, chickens, horses and a calf all abandoned by their owners.

Click here to see photos of rescued pets.

According to the American Society for the Prevention of Cruelty to Animals, between 4 and 6 million animals are surrendered to shelters each year, and approximately half of them are euthanized because there is not enough space to keep them all.

Shelter operators say more animals are being turned over for financial reasons than in the past, and those that don't make it to the shelters are either set free on the streets to fend for themselves or left to starve in foreclosed houses, according to animal welfare groups around the country.

"We are just getting inundated. All of the shelters in the county have been inundated with pets surrendered or abandoned by their owners because of the huge foreclosure rate," said Judith Gardner, president and CEO of the Arizona Animal Welfare League in Phoenix.

She said about 2,000 pets pass through the group's shelter every year, and they expect to have about 300 in their custody at the end of the year.

"Maricopa County (in the Phoenix metro area) has a huge overpopulation problem. We have thousands and thousands of animals that are left at the humane society and we get them from there and can keep them until they're adopted. Because of the foreclosure problem, it's much bigger now," Gardner said.

There were 3,745 foreclosures in Maricopa County in October, according to a realty study by Arizona State University's Morrison School of Management and Agribusiness. In September, there were 3,655 foreclosures in the county.

"There are so many stories of animals being abandoned — left at a foreclosed home with no food or water. It's just pervasive," Gardner said.

In Massachusetts, horse surrenders are on the rise at the SPCA. Its Nevins Farm shelter now has 30 horses, most of which were given up because of the expense of keeping them. "It is a little bit scary because a few weeks ago we had five horses come in one week," said spokesman Brian Adams.

"Horses are one of the larger-ticket items for animal care that have been surrendered to us. We have 43 percent more horses this year than we were taking care of last year," he said. Each costs several hundred dollars a month to care for, and this month the MSPCA will spend about $15,000 on the horses.

The Michigan Humane Society has also seen more pet surrenders due to the financial crisis.

"It's always been one of the top reasons, but it's even more so today," said Nancy Gunnigle, spokeswoman for the organization.

Exotic animals, like alligators and iguanas, are expensive to keep and their surrender is also on the rise, she said. "We still find large reptiles in inappropriate housing. It's not uncommon. Those animals add a strain."

About 40,000 animals are surrendered each year to the Humane Society in Michigan, and about 10,000 are adopted. The adoption rate has dropped 5 percent this year.

Gunnigle urges pet owners who feel they're out of options to surrender them to a shelter rather than abandon them on the streets.

"If you have to relinquish your pet and you're not able to re-home them yourselves, never abandon the pet. Never leave them behind outdoors or in a closed home. It's never the right choice, she said. "It's illegal and it results in extreme suffering for the pet, because they might not be found for weeks."

Animal adoption fees start at about $50 and go up from there, the shelters say, but some don't want the fee to keep would-be owners from adopting.

The ASPCA in New York City is hosting two "Three for Free" events in December, giving away adult cats over 3-years old to would-be adopters without charging its typical $75 adoption fee.

"What we found is that there are lots of folks who make great pet owners who would love to have a cat but haven't thought of it before because of the financial burden of paying that fee," said Gail Buchwald, senior VP for ASPCA.

The society first ran the program in September and then did follow-ups with the new pet owners to see how the animals were being treated.

"These homes were not at any higher risk of relinquishment," she said. "They were solid homes with loving pet owners and these were cats that were getting adopted that would have otherwise stayed in the shelter."

Nationwide, the ASPCA is seeing an increase in surrendered dogs, Buchwald said, but cats seem to be weathering the storm better.

"Cats are somewhat less expensive because of the sheer volume of food they require versus dogs," Buchwald said. "Dogs tend to have other associated expenses, and if you're moving into a new home, it's much easier to conceal a cat. If you have to move into a rental property or a no-pets-allowed leasing facility, then it is easier to deal with a cat than it is to deal with a dog."

But Buchwald cautions that abandoning a pet is never an option.

"Putting an animal that you can't care for anymore or leaving it behind in a home that's being abandoned is not the right way to deal with a pet," she said.

"As difficult as it sounds to bring a pet to a shelter, its far better than being locked up in a foreclosed house or abandoned and put out on the street. Those fates are much, much worse for the pet than having a roof over its head, being given food and water and cared for by shelter staff."