In the first cage, Max the 10-month-old cocker spaniel was all thumping tail, floppy ears and oversize puppy paws. Marilyn Jeffery poked a finger through the metal bars and cooed. In the next cage over, a pile of orange and white kittens napped one on top of the other, oblivious to their rambunctious neighbor.

Jeffery, of Potomac, usually makes regular trips to the Humane Society of Montgomery County's animal shelter in Rockville just to watch the dogs and contemplate getting a companion for her "slightly out of control" terrier.

But on this day, the animals came to Jeffery via the Humane Society's new mobile adoption unit. The 29-foot-long, $110,000 van is outfitted with enough cages for more than a dozen animals, a merchandise corner and a private sitting area for people to get to know their potential pets.

It is one of only a few such units in the country and the only one in the Washington area, according to Kristie Morrison, the Montgomery Humane Society's outreach coordinator. The van brings animals for adoption to shopping malls, pet stores, community centers and fairs throughout the county.

At the Holiday Park Senior Center in Wheaton recently, a steady stream of senior citizens stepped into the van to see the animals, which included rats, hamsters and rabbits in addition to dogs and cats.

Instead of adopting a dog, Jeffery, who teaches computer classes at the senior center, signed up to volunteer with the Humane Society to help with graphic design and public relations.

For Morrison, the van not only offers people the opportunity to adopt animals but also serves as an educational resource.

"I like to bring information to the public. That's vitally important. We want to make sure the animals who already have homes are well cared for," said Morrison, who arrived at the center with a sheaf of pamphlets on spay and neuter programs and pet care.

She also brought her foster pet, an Australian cattle dog, an extra-terrestrial-looking canine with huge pointed ears and leopard-like spots. Morrison dubbed him Little Dog and is teaching him to respond to sign language because he is deaf. A simple flick of the wrist should convey the message to lie down, but because 10-month-old Little Dog was in the midst of an exuberant romp with Max the cocker spaniel, he paid little heed.

Most of the animals in the van are foster pets, meaning that volunteers take them home and care for them for up to six months while they await permanent owners.

The process for adopting a foster pet is the same as that for adopting any of the other 10,000 animals brought to the shelter each year. After people identify a pet they would like, either at the shelter or in the van, they must fill out an application and be interviewed. Each member of the household in which the pet will live must visit the animal within 24 hours.

"Even if the child is 2 years old, we want them to meet the animal. They might be scared or allergic, and it's better to find out now rather than later," Morrison said.

During the interview, Humane Society workers ask such questions as how much time the owners will be home. If the owners will be working long hours, they are steered toward an older dog who needs less attention than a puppy.

New owners must agree to spay or neuter their pets. That cost is included in the adoption fee, along with that of any vaccinations the animal received at the shelter. The approximate cost to adopt an animal is $100.

About 65 percent of the animals brought to the shelter are adopted, a relatively high percentage compared with other shelters, according to Morrison.

"I think this is an animal-loving community," she said.

For some people visiting the van, the question was not if they wanted to adopt a pet, but rather if they should give one up.

Robert Dickman, of Silver Spring, was agonizing over whether he should take his miniature schnauzer puppy to the Humane Society. Dickman, 79, said he discovered the puppy requires too much care and attention and makes it difficult for him to travel.

"I don't want to give her to just anyone," he said. "She needs a back yard to roam around in."

Morrison told Dickman that because his dog is a pure bred, it would be easier to place and that applicants would be screened to make sure they could provide the care and space needed for the dog.

Although none of the animals was chosen while the van was at the senior center, more than a dozen pets have been adopted from the van since October.

Nancy McCarthy, 56, of Potomac, didn't make up her mind that day. She has one cocker spaniel and would like to get another older, housebroken one.

"I think it's great to bring the animals out to people so they can see them," she said. "This way, there's more of a chance they'll be going home with someone."

The mobile adoption unit will be at the Upcounty Regional Services Center at 12900 Middlebrook Rd. in Germantown from noon to 4 p.m. today. It will visit Bone Jour Pet Grooming and Doggie Cafe, at 4927A St. Elmo Ave. in Bethesda, from 11 a.m. to 4 p.m. on Saturday.

For more information, call the Humane Society at 301-279-1026 or visit its Web page at www.mchumane.org.