The late spring and early summer are ideal times to expand the family — to include a new dog.

The weather allows the dog to explore the property and get a lot of its energy out. Plus, children likely have more time to play with the pup.

But families shouldn't rush out to get a dog, or simply pick the cutest one of the litter, advises Cheryl Peterson, author of "Please Oh Please Can We Get a Dog?" (Howell Book House).

A new dog won't be "new" for long; it must fit into the family and the family's lifestyle for the long haul.

"The first question is, 'What's the family's activity level?"' says Peterson of Woodstock, Ill., who also is an AKC judge, owner of the canine training facility The Finishing School, and "mom" to three weimaraners and three vizslas.

"Movie-watchers and computer enthusiasts probably don't want a border collie. They'll drive each other nuts. They should pick a breed — maybe a toy breed — that can get exercise just moving around the house. Joggers will want a more active dog, probably a larger one who can go the distance. You'll end up carrying a Yorkshire terrier," Peterson says.

Families who take summer camping trips might consider a herding breed, such as a collie or sheepdog, that won't take off, Peterson suggests.

And for families do a lot of traveling, they might consider a cat instead of a dog. "A cat can stay home with an extra litter box and more food," she says. "A dog is more like a child. It depends on your services to survive."

Then there's advice from Stanley Coren, author of "Why Do Dogs Have Wet Noses?" (Kids Can Press): "The common complaints when a dog doesn't seem to be working out is that it's too big and strong, or too active. If you're choosing between two breeds, go for the smaller and less active — unless your family's idea of a quiet Sunday is jogging 26 miles."

Coren, a psychology professor at the University of British Columbia who studies dog behavior and serves as an instructor with the Vancouver Dog Obedience Training Club, also says that the characteristics that endear one dog to one family might turn off another.

"Terriers bark. Regardless of their size and shape, all terriers bark. ... For people having a first dog or who live in an apartment complex, terriers probably are not a great choice. Not that they can't be a good dog but they do carry that extra baggage," he says.

Coren says that sporting dogs tend to be gentle in their temperament — at least in their older years. "Spaniels, retrievers and setters are good family choices, but you do have to survive setters' and some retrievers' puppyhood!"

Toy dogs can be easy, as long as families realize that the dogs have to be trained even though they're small enough just to be scooped up if they get into a scrap, Coren says. Kids usually feel safe approaching a toy dog but the risk to the children is the same as a large one, especially if it's not trained.

He suggests the cavalier King Charles spaniel, which is 13 inches at the shoulder and 20 pounds is "a relatively undiscovered gem." Coren has one of these "incredibly sweet and reasonably adaptable" dogs at home.

Peterson urges against Italian greyhounds for families with younger kids because their bones are so delicate, and she'd avoid Newfoundlands, only because they grow so much bigger and faster than kids, they might end up hurting the children by accident.

But before you get that far, to be sure your children are ready for a dog, you should be able to answer yes to both these questions: Are they good at following directions? Are they doing their chores?

"If yes, involve them in the entire process of getting the dog," says Peterson. Let them do some of the breed research, pick out the bowl and go to the pet store to buy food and toys — it's all part of the bonding process. If not, you might want to wait.

Bonding is very important, but, luckily, puppies make that easy by being mostly sociable and loving. It's OK if it's an older dog, too, Peterson adds, they need and give love just as much as a puppy.

When a dog first arrives at its new home, lock the front door and the outdoor gates and let it loose. Let it come up to the kids on its own time, Patterson says.

Next, sign up for obedience class. "You have to teach the owner more so than the dog. Maybe start with the adults and then do the kids. This way the dog will be a little trained so the kids will likely have more success when it's their turn and won't be frustrated," she suggests.

Coren adds: "Children have to realize the dog isn't a plug-and-play toy. It might turn into Lassie, but it'll take a few years. It's probably a clumsy cute thing that's quite a bit of work at the outset."