A lot of these fine-furred friends being put to sleep are older dogs; this can mean as young as 3, or 4 even. The attraction of a puppy is very strong in mankind and pet chain stores and breeder advertising don't make it any easier on us; we're often told to get a puppy because it's easier for the animal to grow with you, with your children, in your home, with your specific life routine, or work hours, etc... The excuses to purchase a puppy over a senior dog are endless and I can't even fathom covering them here.
What I can do is give you a few questions to ask if you do make the choice to adopt an older dog into your home rather than supporting the endless supply of unethical breeders North America is home to:
What is the dog's history?
Was the dog found as a stray, turned in by the owner, a rescue, abused, etc...?
If the dog was found as a stray, you may have some extra behavior issues to deal with, especially if the dog was on its own for awhile. The dog may not recognize you as a necessary part of its life and you may have to work hard to integrate it into your family pack.
If the dog was a rescue, or was abused, you will want to know the details to determine if you are prepared to handle any problems that come up. Some dogs will be overly shy, or submissive; others may be aggressive, or dominant, or hate kids. Most are well-adjusted, don't misunderstand, but you need to know in order to evaluate the situation.
Why is the dog available?This is obvious for strays, but when the owner turns the dog in you need to find out why. Was there a divorce? Are they moving? Is the dog showing signs of aggression toward children? Did it just not "fit their lifestyle"?
Basically, are you dealing with a family pet that is being put up for adoption because of a family situation, or because the dog is a behavioral nightmare that they most likely created?
I think everyone of us have strong opinions on people who dump their family pets at the shelter just because the dog is inconvenient - when you get a dog, you are responsible for it for life, and leaving it at the shelter when it becomes "inconvenient" puts the animal at a much higher risk of being euthanized than finding it a screened home on your own, which you can keep in contact with.
Does the dog have any behavior problems?
Remember that many "owner drop offs" are left because they have a behavior problem that the original family couldn't deal with. Make sure you're ready to deal with it as this dog does not need to be dumped again.
Many dogs are put up for adoption because they soil the rug, chew shoes or bark too much. Some are available because they nip at the family children or hurt the cat. Most of these are correctable problems, but you need to evaluate any problems very carefully. Are you ready to handle a full grown dog that piddles every time you greet it? Do you have the time required to retrain a dog that jumps the fence?
The only behavior problems that really render a dog unadoptable, in my book, are human aggression problems. If a dog is aggressive towards children or adults, you should think very, very carefully about whether you are willing, or able, to deal with it. This is very serious, and sometimes cannot be corrected.
How is the dog with kids and other animals?This is really an extension of the previous question - most shelters do extensive testing of their adoptable dogs to determine if they can go to a household with kids or cats or other dogs. If you have kids, or cats, you will want to know that the new dog will be able to interact with them appropriately. If you have another dog, make sure that the new dog will get along and that you are prepared to handle a multi-dog household.
Does the dog have any health problems?While shelters make every attempt to assure that the animals they adopt are completely healthy, you should ask about other possible problems, such as hip dysplasia or thyroid problems or other chronic diseases. In my years of volunteering as a teenager at a local Vet Clinic I once saw a beautiful Amstaff brought in simply because she chewed the paint off a door frame and the girl's parents said she couldn't have the dog any longer. This was her second time being unwanted and the dog was a mere two years old. This is a correctable problem, but you will need to know about it in order to deal with it.
Is the dog spayed or neutered already?I say already because most shelters require that you have any dog spayed or neutered when you adopt. Many will have already done this before adopting the dog out (and in my opinion that is the safer way for them to run their business) but you should check. Sometimes it will be part of the adoption fee, or part of the fee will be refunded when you provide proof of desexing.
I hope asking these questions will empower you to bring an older dog in need into your home rather than supporting another pet store, backyard breeder or puppy mill.