Shelters host an overwhelming variety of dogs fit for all occupations and households; rather than restricting yourself to one breed or age, you can see a huge variety and see what might work best for you — and the dog in question. After all, they choose you, too.

There's no question that some dogs struggle in rescue care, but not all of them are there because they're "difficult" or "aggressive." Most are just unlucky and, like all dogs, in need of good training and a loving home.

If you're intent on a dog of a particular breed, don't be surprised if they show up in your local rescue too. Some breeds, like purebred Akitas, show up in shelters regularly because owners fail to realize their particular breed needs and give them up. You can also seek out local rescues that specialize in the kind of dog you're looking for. The Humane Society estimates that 25 percent of all purebred dogs in the U.S. are in shelters right now.

A pet store might seem like an obvious place to start if you're looking for a canine companion, but buying a dog from a store isn't like buying a sofa. Pet store dogs may come from puppy mills, which are often criticized for their inhumane practices.

There's no getting around the fact that some rescue dogs in the U.S. may be euthanized before they can find an owner, simply because their shelters run out of room. But fortunately, the numbers are going down: the ASPCA estimates that 1.5 million animals are euthanized in shelters yearly now, compared to 2.6 million in 2011, because people are more interested in rescuing animals these days.

The number of dogs in shelters across the U.S. is startling. Because there's high turnover, it can be tough to know exact numbers, but the Humane Society estimates 4 million dogs and cats are adopted from shelters every year. That's a lot of dogs that need your help.

Puppy mills and "backyard breeders" — people who unlawfully breed dogs in their homes — aren't reputable ways to buy dogs. The dogs are bred and raised without oversight, so there might not be verifiable information about how healthy the dogs are.

Adopting a purebred dog can cost thousands. Adopting a shelter dog? Shouldn't set you back more than $100 depending on your state and the rescue in question. Many shelters are far cheaper.

Dogs can go into shelters untrained and without much experience of humans or other dogs. Many shelters work extensively on training their animals to help them find a home, including toilet training and socialization with other animals.

Shelters and rescues across the U.S. vaccinate, microchip, spay, and neuter all dogs that pass through their doors, and should be able to identify health conditions before the dog is passed to you. A lot of shelters also have recommended pet insurance providers to help you cope with later medical costs.

According to the ASPCA, 23% of dogs are adopted from shelters versus 34% who have been bought from breeders, some of whom are definitely not working for the best interests of their dogs. Shelters deserve your patronage; they keep down populations of stray animals by neutering and spaying, return runaway dogs to their owners, and are often staffed largely by volunteers.

Desperate for a tiny little tongue licking your face in the mornings? Puppies show up in shelters regularly, particularly when pregnant dogs are brought in; litters are also often given up by owners who can't take care of them. Your dream of a miniature friend is definitely possible at a shelter.

Older animals are plentiful at shelters, so a grey-muzzled chap with all its manners and training in place — no need to break out the toilet-training or teach them how to walk on a leash — is easy to find.

PetMD points out that preconceptions about rescue dogs — that they're dirty, ill, have behavioral problems and have something "wrong" with them — are all unfounded. Get a beautiful rescue dog, shower it with love, and challenge some myths about shelter animals among people in your community.

Pit bulls, Staffordshire bull terriers and variations on their breed are often found in shelters and are particularly vulnerable to mistreatment, thanks to misconceptions about these breeds. Adopting a big cuddly beast can help save it.

Looking for a shelter dog can change you; you can't walk in with a hard-and-fast set of rules ("must have one brown ear") like you could with a breeder. What you see depends on the population of the shelter at the time, and you need to have an open mind and think about the kind of pet you need and want, instead of superficial characteristics.

Shelter and rescue owners are a big community. Your shelter may host events for happily adopted dogs to socialize and owners to meet — or you could introduce your dog to somebody else at the dog park and discover that it's a rescue, too. The common ground is endless.

If you're concerned about your rescue dog having issues, the staff at the shelter are too — and they've likely done work to identify what its problems might be and how to change them. No shelter wants an owner to walk away with a dog that won't work in their household. It's in their interests to make sure you're all on the same page.

Dogs with disabilities, whether they're congenital or related to events like accidents, often end up in shelters, and you can help give these puppers a forever home.

Dogs who've been part of families are given up to shelters all the time, often because of changed circumstances. If you have kids, shelters will often be able to find a dog that's incredibly child-friendly — and you'll discover your main problem is that your kids and dog are now inseparable.

Needless to say, dogs love to be loved — and the gratitude of a rescued animal is something else. Adoption from a shelter gives you the chance to give a home and a future to an animal that's been deprived of both. Who can argue with that?