Perhaps Moses and Harry realize how fortunate they are. But if they do, they’re not talking.

Moses and Harry are cats, 11 and 13, respectively, who are living comfortably in the New York apartment of Maria Pfeiffer.

What’s special about these two felines is that they were both 11 years old when they were adopted by Pfeiffer and her boyfriend.

Senior cats and older dogs — typically animals past age 6 or 7, say the animal welfare experts we talked to — are often deemed unadoptable simply because of age. So they are left to languish in shelters. But older pets can be a joy, Pfeiffer says. "These cats need maybe less care than younger cats," she says. "They’re still youthful. Lovable. It’s not like they get old and grouchy. They might have an attitude, but it’s the same attitude they had as a kitten."

People have misconceptions about older animals. Bunny Hofberg hears it all the time.

Hofberg founded Frankie’s Feline Fund (frankiesfelinefund.org), a New York-based not-for-profit that rescues, fosters and finds homes for senior cats. To that end, she does a lot of adoption events.

"People must think I’m deaf because they say things out loud that they must think I can’t hear," Hofberg says. "‘Oh, you can’t bond with older cats.’ ‘You have to get a kitten.’ All these ridiculous things. That’s so not true."

The story is the same with dogs.

Jennifer Kachnic is president of The Grey Muzzle Organization (greymuzzle.org), a North Carolina charity that provides grants and resources to rescues, shelters and other nonprofits that aid with adoptions, medical screening or hospice care, among other programs, for older dogs.

"We’re trying to educate people on the benefits of adopting senior dogs," she says. "Often times a senior dog is a much better fit than a puppy."

There’s no need for housebreaking, and owners bypass the constant supervision that a kitten or puppy requires.

Conversely, though, if someone is looking for an exercise companion, a senior dog may not be a good fit.

What’s out there: Petfinder (petfinder.com), an online adoption site that works with 13,000 shelters, has nearly 340,000 pets available for adoption, says Sara Kent, the organization’s director of shelter outreach. Of that number, 17,500, about 5 percent, are senior animals.

"I would say the seniors are definitely the most difficult to find homes for," Kent says. "We just recently completed a survey of members and asked what is the hardest type of pet to re-home. The largest percentage, 28, said seniors were the hardest."

What’s more, a lot of senior dogs and cats never get as far as the adoption listings, because many shelters stop trying to find them homes.

\ A big focus of people considering a senior pet revolves around the issues that accompany advanced age.

An older dog or cat may be halfway through its life span, and that means an owner will probably have to say goodbye sooner.

"I hate to use a cliche," Hofberg says, "but it’s the glass half-empty versus half-full idea. Instead of looking at the negative side, look at it as how much you can give each other in the time you have together."

Joyce Paschall, of Palatine, Ill., agrees; she is currently fostering Tootsie, a 7-year-old beagle, her 32nd foster pet.

"When you adopt a senior, you know they have less time," Paschall says. "For us, we keep track of our former foster dogs. … When we hear that one of them has passed on, yes, it’s sad. But then, they had a good last few years. You know that dog (had) limited options. And I really think they’re more grateful."

The vet bill concern: Older animals obviously face the illnesses of advanced age sooner than puppies or kittens, so prospective owners have to be prepared for that. But, as Pfeiffer notes, "You can adopt a cat at age 1, and they could have a serious problem and be gone in a year."

Petfinder’s Kent adds that vet bills are a reality for any owner, whatever the animal’s age.

"Those costs may come sooner with a senior pet," she acknowledges, "but any pet is likely to have those costs at some time in their life."

"Dogs never live long enough," says Arlene Burkhardt, of Bloomingdale, Ill. She and her husband, Kurt, have fostered dozens of older dogs and have given a permanent home to some, too. "We lost our dog last week; she was (an older) dog we fostered and then adopted. She was 11; we had her only a year and a half. … You know you’ll have less time with them, but the love they give you is amazing."

"I’ve adopted a lot of seniors myself," Kent adds, "some you’d expect would be around only a short time. But by giving them great vet care, you can have them for years and years."

Moving in: There’s an adjustment period when you bring any pet into your home. Older animals that have a history of living with a family may settle in more quickly than a puppy or kitten.

"There’s so little aggravation," Kent says.

Pfeiffer has had four senior cats and says they all made a smooth transition.

"When you bring any cat in, you … generally keep them in a smaller space at first so they can get used to the new surroundings," she says. "Once they’re there and using their box, eating the food you leave out, there’s really no adjustment."

Should you do it? If you think a senior pet might be a good match, talk to your vet or the professionals at a local shelter.

Consider fostering an animal before adopting it. Grey Muzzle has extensive and outstanding resources regarding older dogs on its website. You can also sign up for the group’s newsletter.

"Try not to think about age," Hofberg says. "Just meet the (pet). If it’s the personality you are looking for, just adopt it. I’d rather have a little time with a great animal than years and years with one that’s not what I wanted."