In Sacramento, volunteers and students from the University of California, Davis, hold a monthly clinic for the animals of people who live in a camp down by the river, where in winter their tents are spread out in the hollows and under trees to keep out of the wind.

On clinic days, the clients — the unemployable, the inebriated and the infirm — sometimes line up hours before the veterinarians arrive, and the veterinarians often see 150 pets at a clinic, mostly dogs, but cats too, and even rabbits.

It's called the Mercer Veterinary Clinic, named for a science fiction character who embodied empathy. Dr. Thomas Kendall, a volunteer, said homeless people who come to the clinic share what little food they have with animals just to have company and often take astoundingly good care of their pets.

“I have never seen stronger attachments than I have seen at Mercer,” Kendall said in a recent radio interview. “To me, the human animal bond and what it can do for these people, who just don’t have anything, is simply amazing.”

The Mercer has been in operation since 1993. However, in this present, depressed economy, it appears that similar volunteer efforts for the needy are becoming more common in veterinary medicine. At least, they are getting more attention.

Veterinarians, of course, are well known for assisting clients who have difficulty paying their bills and for their involvement with animal rescue operations. But many have noted that when economic times become difficult and the world becomes less materially satisfying, people tend to reorient their priorities and reach out to others more, showing a softer, more compassionate side.

Take Michelle Brownstein, DVM, who practices in a Rochester, N.Y., suburb called Henrietta, for example. She is a former large-animal veterinarian who hurt her back and went into small-animal practice. She was a kid who went away to college and veterinary school, and then came back to her home town to settle, a pattern that is not uncommon in Rochester, where many families go back four and five generations.

One day early this year, she was driving in her car listening to the radio, hearing the bad news and musing on the hard times that have descended on Americans. Eastman Kodak Co. is a major employer in Rochester. It once had a factory complex more than four miles long and its own fully equipped fire department. But then digital cameras arrived and the economy tanked. The company has laid off thousands locally in recent years and announced another 1,300 layoffs in January.

Brownstein’s own practice has been affected by a downturn in visits.

So it naturally occurred to her that people recently laid off might have animals that were suffering because their owners could no longer afford veterinary medical care.

“People were just not coming in with routine stuff,” she said. “So I decided we could either sit around and say, ‘What are we going to do?’ or we could do something.”

She called some of her suppliers and lobbied for support, and then held a free Saturday clinic for those who qualified. Her Pets in Need operation drew 15 people with 35 pets, including a man with eight Mastiff-Wolfhound puppies that needed vaccinations.

Her efforts made the local television and radio news. She now plans to hold another clinic in April.

More than 30 people volunteered to help out with the clinic, and of the 13 suppliers Brownstein contacted, 12 gave donations, and their largess was astounding.

“We literally had truckloads,” she said.

Brownstein said she was not really worried about undermining the business of other veterinarians, and she was not hoping to drum up new clients. The people she serves have no money, so they were not going to be spending anywhere, she said.

At the same time, she was not looking to provide assistance to those who were chronically unemployed. In order to attend the clinic, individuals had to fill out an application and needed a reference from someone like a social worker or clergy member.

“I’m not looking to steal anything from anyone,” she said. “I am just looking to stay busy while times are tough.”

An effort with a broader mandate is Feeding Pets of the Homeless. It’s a project that was begun last year by Genevieve Frederick, of Carson City, Nev. She provides small grants to just about any veterinarian who has a plan to provide service to those without resources and who is willing to fill out an application, at least for now.

Nobody really knows the proportion of homeless people who have a pet, though it is estimated to be about 5 percent to 10 percent.

Her story is that she owned a small publishing company and had a book written with a local veterinarian that did fairly well called "Happy Tails – Hilarious Helpful Hints for Dog Owners."

Because of the book, she went to a conference in New York City, looked around, and found the contrast to her own less-urban municipality appalling. She saw the homeless all around and noticed how many had animals.

She returned to Nevada, and began an effort to help veterinarians help those less fortunate. As word got out about the endeavor, donations began pouring in. She got $3,000 from the J. Robert Nonemaker Foundation for Small Animals, Inc., $2,000 from the On Shore Foundation, Inc., $500 from the PETCO Foundation and more than $9,000 from regular individuals.

In October, her group gave out its first grants to seven veterinarians.

One of those who received a grant was Kevin Stoothoff, DVM, who practices in Ocala, Fla., a place that many people who are homeless migrate to when the snow begins to fall in the north.

He used his $600 grant to start a noontime clinic twice a month at a local soup kitchen.

Stoothoff, a practicing Catholic, said he was a little intimidated when he conceived the idea, since the kind of people who live on the streets are not the kind of people one usually sees in the clinic, and they are often mentally ill. He also worried that he might find many animals severely malnourished or so debilitated they needed to be euthanized.

But Stoothoff was surprised. The people in the soup line, who show up hours before serving starts, were a bit skeptical at first, but he has held about 12 clinics to date and, “Now they are waving at us as we pull into the parking lot,” he said. The animals tend to be well cared for and he has not had to put one to sleep.

In addition to vaccinations and treatments, he has been able to give out about a thousand pounds of donated food, he estimates.

“As long as the donations continue to come in I will be able to sustain this ministry indefinitely,” he said.

Ronald Chaikin, DVM, another grantee, has a slightly different calling than Stoothoff. His practice in Brooklyn, N.Y., is located in an area where there are a lot of housing projects. The projects have strict rules about animals being vaccinated and neutered. The owners either comply or the animal goes.

Chaikin said he has as many as 40 people a week walking into his clinic with a story about an intransigent landlord and a lack of any disposable income.

He has used his grant to help these people. In fact, it is already spent. He is not ungrateful, but he calls the grant a nice “gesture.” The need is just so great where he is, he said.

“New York is an expensive place, I don’t need to tell you,” he said.

While Chaikin works in one of the most urban environments in the world, Dr. Eric Davis provides free service on American Indian reservations and in other remote locations.

Davis’s philanthropy also has a longer history.

In 1995, Davis, an equine surgeon, was an assistant professor at the University of Tennessee when he was invited along with a group of medical volunteers headed for the Rosebud Sioux Reservation in South Dakota. He decided to go.

The group had never included a veterinarian. Davis said he was more or less on his own when he arrived on the reservation, and he waited a day or so for some direction. When none came, he decided to head down the dusty roads and knock on some doors to see who needed a veterinarian.

The need for his expertise became apparent. There were largely neglected, semi-wild horses. There were untamed, mongrel dogs loping along the streets.

“There was obviously just a great need,” he said. “Dogs were running all over the place. Children got bit.”

The experience made him aware of how desperately scarce veterinarian services are on reservations and in other remote areas. In a survey that Davis’ group conducted at clinics it put on in Appalachia recently they found that 65 percent of the animals seen had never before been to a veterinarian. In the Navajo Nation, it is estimated that 160,000 stray dogs and cats roam free.

Davis said that 80 percent of the horses he sees on reservations are not even halter broken. “The definition of a tame horse (on the reservation) is a horse you can rope on foot,” he said.

That first trip led to others, and not long afterward, Davis set up a project he called Remote Area Medical Veterinary Services and asked for student volunteers. Those who got involved received valuable surgical experience. Davis then quit academia.

The effort eventually was taken over by the Humane Society of the United States, which now provides much of the funding, and it was renamed the Rural Area Veterinary Services (RAVS) project, of which Davis is the director.

During the past 10 years, Davis and RAVS have visited more than 40 reservations, and these days, he does not travel light. The teams that make the trips often include three to five veterinarians and a dozen or more veterinary students. They take laboratory capabilities and equipment for surgeries. It usually takes the team a full day to pack.

In 2008, RAVS provided an estimated $1 million in veterinary care and saw 6,500 animals. In a typical day, they might do 50 spay/neuters and a greater number of vaccinations.

The students are all volunteers who need to pay about $200 for their food and lodging, and the trips can last three days to six weeks. Davis said he generally recommends that students commit to at least two weeks.

It turns out, however, that not all of Davis' good deeds involve a long road trip to the hinterlands. With foreclosures and layoffs increasingly commonplace, he has been involved in the kind of private, charitable works that generally go unheralded, except that he wrote an article about it — not because it was unusual, but because it was emblematic.

He wrote about a pickup truck that stopped by the side of Old Stage Road near Salinas, Calif., in the Gavilan Mountains, which are featured in a number of John Steinbeck stories. Somebody in the truck threw a box to the ground and sped away.

After some time, the box began to shake and seven Chihuahuas tumbled out. They all scurried off. Fortunately, Davis said, someone spotted the truck and the dogs, and the neighborhood includes a veterinarian, a veterinary technician and someone who works with horses; so area residents mobilized and chased the dogs down. They had to trap three of them, but all of the dogs were captured.

The dogs spent the night at Davis’ house, and it was immediately apparent to him that the animals were well behaved and had been pets.

He noted that the region has not been spared by the economy, and according to his wife, Dr. Ila Davis, who is the shelter veterinarian for Salinas, 200 more pets relinquished in February compared to the same month, last year.

“It’s just sad (the Chihuahuas) had to go through this experience in the first place, and that many other pets put out by an economic downturn won’t be so lucky,” he said.