I am proud to be the owner of a former shelter dog who is a mutt (my pal Buster might look and act just like a Black Lab, but I assure you, with pleasure, that he is a mutt). I am someone who will always own a dog, and I have decided that I will only own rescue or shelter dogs. Therefore I am a big fan of October, which is Adopt a Shelter Dog Month.

Any person who has decided to bring a new canine friend into his life should ask a number of questions of himself and of the shelter. This article is designed to help guide such a person to the appropriate shelter dog, and also to help such a person choose a healthy dog. It should also help people make sound decisions about health care for new dogs in the future.

Behavioral and lifestyle questions for yourself and shelter staff

The decision to adopt a shelter dog (or any dog) needs to be come from introspection. Shelters have dogs to suit any situation or lifestyle. What sort of dog do you desire? What sort of dog can you handle?

The latter question is the more important one. Human-canine relationships work only when the human is the leader. I do not subscribe to schools of thought that recommend humans be aggressive or domineering with dogs. However, dog owners must be sufficiently competent and confident to lead the relationship gently. This is for the safety of the dog and all of the people who meet the dog.

Unfortunately I have met many people who have misjudged their confidence and competence when adopting dogs. The result invariably is a bad relationship in which the dog does not respect its owner. A shy, fearful, hesitant, or inexperienced owner who adopts a spirited, challenging dog will probably suffer with behavior problems over time. These behavior problems can devolve into a situation that can be fatal for the dog; euthanasia for behavior problems unfortunately is common in this world.

If you are an experienced dog owner who enjoys the robustness of a relationship with a spirited dog, then by all means adopt one. If you are inexperienced or if you lack confidence, then you need to look for an easy going, easy-to-handle dog.

Other things to consider when adopting a dog include its size, age, and activity level. All people, but especially families, should inquire about the dog’s expected behavior around children. It also is important to know how the dog gets along with other dogs.

Your dog’s needs should match your lifestyle. Active families that adopt young energetic dogs will generally find the match to be good. Couch potatoes who adopt high-energy dogs might see their pets suffer.

Serious mismatches can be catastrophic: I have seen old people end up in ambulances after their large, young, rambunctious pets knocked them over. I have seen large dogs struck by cars when they escaped from small people who couldn’t hold onto the leash.

Fortunately, such severe mismatches aren’t common. And remember that dogs are very highly adaptable — Chihuahuas can and do go on long hikes, and most Black Lab mixes can, if asked, lounge around all day.

Medically relevant questions for shelter staff

Although some folks love to take on charity cases, most people prefer to adopt healthy pets. And regardless of whether you desire a dog with special needs or one that is robust right from the start, your vet will need to know the answers to certain questions in order to offer the best care moving forward. (It should go without saying — but I’m saying it anyway — that one of your first actions after adopting a dog should be to take him to the vet for a routine checkup.)

Dog adopters will do well to ask the following questions:

• Has the dog shown any signs of illness during its time in the shelter? Some issues, like kennel cough, are common and are not a big deal. But dogs that show signs of failing to thrive might have significant underlying health problems. Other dogs might have suffered major illnesses, such as parvovirus, from which full recovery is possible. It is important for you and your vet to know your dog’s background.

• What vaccinations has the dog received, and when? Your vet will need this information to determine when your dog next needs shots, and also what his susceptibility to certain diseases will be.

• When was the dog dewormed? Intestinal worms are ubiquitous in puppies and are very common in the sorts of adult dogs that end up in shelters. Some intestinal worms can spread to and cause serious illness in children. A deworming protocol should be developed for all new adoptees; the protocol will depend upon what was done at the shelter.

• Has the dog been tested for heartworm? Is he on a heartworm preventative? Heartworm disease is now considered a year-round, worldwide health threat. You and your vet will need to know your dog’s heartworm status.

• When and how was the dog treated for fleas? Regular, high quality flea preventatives are effective at preventing the misery that comes from infestation with these despicable parasites.

• What has the dog been eating? How much has he been eating? Rehoming a dog is stressful. Stress can cause gastrointestinal upset. Diet changes also can cause gastrointestinal upset. Therefore, it’s generally best not to switch diets immediately after adoption. Once the dog has settled in to his new home a gradual diet transition can occur.

• Finally, be sure to ask about desexing of the dog. Desexing is a fancy way of saying spaying or neutering. Most shelters spay and neuter all pets before they are adopted. However, you should confirm whether the surgery did, in fact, occur at the shelter. For instance, a dog that turns up in a shelter with no testicles in his scrotum might appear to have been neutered, but might in fact not be. So-called cryptorchid dogs — dogs without visible testicles — are at high risk for testicular cancer.

As you consider which of the many deserving shelter dogs to take home, remember a few other things. Dogs have evolved to be our companions. They are highly adaptable, and they naturally adjust their lives to blend with ours. There are many ways that things can go wrong when choosing a dog; however, usually nothing goes wrong at all. Congratulations on finding your new friend.

Read more by Dr. Eric Barchas:

• Why Do Some Dogs Keep “Showing Their Lipsticks”?
• Let’s Talk About Dogs and Euthanasia: When Is It Time? Should You Be Present?
• What to Do Before You Get to the Vet in 12 Emergency Dog Situations
• 12 Dog Emergencies That Need Immediate Veterinary Attention
• Just How Dangerous Is It to Falsely Call a Pet a Service Dog?

Got a question for Dr. Barchas? Ask our vet in the comments below and your topic might be featured in an upcoming column. (Note that if you have an emergency situation, please see your own vet immediately!)