It’s surprising how many people don’t ask themselves this simple question before they get a pet. Adopting an animal because of a chance encounter at the shelter or because the kids have been pining for a puppy often ends up being a big mistake. Don’t forget that pets may be with you 10, 15, even 20 years.

Dogs, cats, and other animal companions cannot be ignored just because you’re tired or busy. They require food, water, exercise, care, and companionship every day of every year. Many animals in the shelter are there because their owners didn’t realize how much time it took to care for them.

The costs of pet ownership can be quite high. Licenses, training classes, veterinary care, grooming, toys, food, kitty litter, and other expenses add up quickly.

Flea infestations, scratched furniture, accidents from animals who aren’t yet housetrained, and unexpected medical emergencies are unfortunate but common aspects of pet ownership.

Many landlords don’t allow pets, and most rental communities have restrictions. In addition, certain types of dogs are often excluded from homeowner insurance policies, or the owners aren’t allowed to renew or continue their coverage. Make sure you know if and how you are limited by housing-related policies before you bring a companion animal home.

If you’re a student, in the military, or travel frequently as part of your work, for example, waiting until you settle down is wise. If you have kids under five years old and you’re thinking about adopting a small mammal like a rabbit or guinea pig, you might consider postponing this decision since many small mammals present a risk of Salmonella.

Animal size is not the only variable to think about here. For example, some small dogs such as terriers are very active—they require a great deal of exercise to be calm, and they often bark at any noise. On the other hand, some big dogs are laid back and quite content to lie on a couch all day. Before adopting a pet, do your research—surf the Internet, talk to pet-owning friends and neighbors, and use shelter staff as a resource. That way, you’ll be more likely to choose an animal who fits your lifestyle and living arrangements.

Having your pet spayed or neutered, obeying community leash and licensing laws, and keeping identification tags on your pets are all part of being a responsible owner. Of course, giving your pet love, companionship, exercise, a healthy diet, and regular veterinary care are also essential.

You’ll need either reliable friends and neighbors or money to pay for a boarding kennel or pet-sitting service.

When you adopt, you are making a long-term commitment to care for an animal. That said, good people sometimes find themselves in unfortunate circumstances that prevent them from holding onto their pets. If this should happen, be prepared to take a proactive role in finding a new home for your animal companion.