After snuggling dogs at adoption events, reading online pet profiles, and visiting shelters, you're ready to adopt a four-legged friend. But before you take home one of the 1.6 million dogs adopted in the U.S. each year, remember that age matters.

“It's important to consider the life stage of the dog because you want to ensure that you can provide the right care,” says Michelle Lugones, DVM, a veterinarian at Best Friends Animal Society in New York City.

“Consider the dog's personality and day-to-day needs and how that fits into your family and situation. …. Be realistic about what you're willing and capable of in terms of caring for a dog, because it's a long-term commitment.” 

Adopting a Puppy

The big eyes, the round belly, the floppy movements -- who can resist a playful puppy? But for all of their adorableness, puppies can be a handful.

You’re responsible for housetraining, socialization, and teaching basic manners. And then there's the constant monitoring to make sure your pup doesn’t chew up your shoes or turn the garbage into a doggie buffet.

“There’s nothing cuter than a puppy,” says Gary Weitzman, DVM, president and CEO of the San Diego Humane Society. “But with all that cuteness comes a lot of mess and training. It’s important to be sure you have the time to devote to consistent training and the patience to reinforce it again and again.”

On the plus side, adopting a puppy gives you the opportunity to help shape your pup's personality and behavior. And you'll likely get to spend 10 or more years with your dog.

But keep in mind that puppy behavior can last until age 2 or so. And you can't always tell how big a puppy will grow, especially if it's a mixed breed. So you might end up with more dog than you bargained for.

You should also consider the cost. The average cost of the first year of owning a dog can range from $2,674 for a small dog up to $3,536 for a giant breed like a Great Dane. And Lugones notes that puppies need extra vet care to get off to a healthy start. If your pup wasn't spayed or neutered before adoption, you'll need to spring for that operation. It's often done when a puppy is 6-9 months old.

Adopting an Adult Dog

Want to skip the sleepless nights, chewing, and house

raining that come with raising a puppy? Adopt an adult dog.

“Many people want puppies, but you shouldn’t write off an adult dog,” says Weitzman, a certified animal welfare administrator. “What you see is what you get with an adult: the size of your new dog, his coat, and probably his temperament.”

Dogs reach adulthood around age 2. So you could still have many happy years with your four-legged best friend.

Lugones notes that adult dogs are often already housetrained, leash-trained, and crate-trained as well as past the destructive puppy phase.

Ask rescue groups for information about an adult dog’s personality to learn how the dog behaves and whether they get along with children and other dogs and cats. Sometimes, adult dogs need to unlearn bad habits, or they need a refresher course on housetraining at a new home. But it's not true that you can't teach an old dog new tricks. 

Adopting an adult dog is about more than finding a loving companion. It could also save the life of a shelter dog.

“It tends to be more difficult to find homes for adult dogs because many people seek out puppies,” Lugones says. “So you're providing a loving home to a dog that may not otherwise get that chance.”

Adopting a Senior Dog

Don’t let their gray muzzles fool you. Many senior dogs still have plenty of spunk.

Dogs are considered senior at 7 years, according to the American Veterinary Medical Association. But that's really closer to middle age for smaller breeds like the Yorkshire terrier, Chihuahua, Pomeranian, and French bulldog, which may live 12 years or longer.

Senior dogs may happily tag along on walks and love trips to the dog park. But they do tend to have less energy than younger dogs, which means more quality time snuggled up on the sofa.

“Nothing is sadder than seeing senior animals in shelters grieving the end of the lives they knew,” Weitzman says. “It’s true that you’ll have less time with a senior pet than a puppy, but for that pet, that extra amount of time is priceless. Many people adopt senior pets repeatedly because the rewards are so great.”

While senior dogs are unlikely to need housetraining or require hours of exercise, they do have certain health needs.

“Senior dogs may have illnesses that require long-term treatment [and] should see their veterinarians more frequently for exams and monitoring,” Lugones says.

Some older dogs may also need accommodations like ramps to get up and down stairs. Or they might take regular medications or need dental care. Consider whether you can afford the vet care and spend the time to meet their needs.

Lugones believes the efforts are worthwhile. "I like to think of time spent with pets in terms of quality and not quantity,” she says.

Before adopting a dog of any age, Lugones suggests that you:

• Research the nature of the breed to understand temperament and exercise needs.
• Ask the rescue group or shelter about any known illnesses (and get medical records, if available).
• Spend time with a dog before adopting to see if they're the right fit.

“It's a big decision,” she says. “By thinking it all through, you set up everyone for success.”