For many travelers, our pets are part of our family. While we might not bring Fido along on a vacation, we don't want to leave him behind for an extended stay or when we're moving to a new place.

Checking a pet into the cargo area of a plane can cause anxiety — for both pets and their humans. So, the natural question many pet-owning travelers might have is: Can I buy my dog a seat on an airplane?

That answer depends on which airline you're flying. Let's take a look at airline policies on buying a seat for a pet, plus a workaround if the airline won't let you buy your dog an airplane seat.

Size limitations for carry-on pets

Before we dig into specific airline policies, we need to address the biggest limitation of flying with pets: size requirements. Almost every airline restricts carry-on pets to a carrier that fits under the seat in front of you.

Additionally, airline policies generally require that there's enough room for your pet to stand and turn around in their carrier. Plus, most airlines restrict which species can be carried on as pets.

Put together, these policies generally limit travelers to carrying on small dogs and cats.

There's one notable exception, though. JSX lets you carry on medium-to-large dogs up to 79 pounds as long as you purchase an extra seat for them. JSX charges a $100 fee for small-size cats and dogs that fit in a carrier under the seat in front of the owner.

These policies easily make JSX a smart choice for flying with your pet.

Airlines that let you buy your dog a seat on an airplane

We could only find two airlines that will sell you an adjacent seat specifically for your pet: JSX and JetBlue Airways.

JSX

JSX passengers can bring up to a 79-pound dog on board with them after purchasing an additional seat.

Even better, the dog isn't restricted to a carrier if you purchase an additional seat for them. You simply have to keep them leashed.

However, even though you bought the seat for your pet, your pet isn't actually allowed to sit on the seat. Instead, they must sit in the floor space in front of the seat you purchased for them.

JetBlue

JetBlue also specifically allows travelers to purchase an extra seat for their pets, though the pet must still be small enough to fit in a carrier.

While your pet's carrier must be stowed under a seat for taxi, takeoff and landing, JetBlue lets you place their carrier on your extra seat during the flight.

Alternative: Buy an extra seat

Although some airlines won't let you technically buy an extra seat for a pet, you might be able to purchase an extra seat for yourself. These policies are typically intended for passengers looking for some extra space, comfort or privacy.

Here's a brief list of airlines that let you purchase an extra seat and the terms the airline uses for this seat purchase:

Alaska Airlines: Comfort Seat.

American Airlines: Extra Seat.

Delta Air Lines: Extra Seat.

Even if you buy an extra seat for your pet, most airlines require that your pet stays in its carrier the entire flight. That means your dog won't be able to sit directly on the airplane seat, even if you purchased that seat for them.

Still, buying an extra seat can let you stretch out a bit. You can place your pet's carrier under the extra seat, or you can simply use the extra seat as a buffer from other passengers.

Earning miles for pet travel

At NerdWallet, we love earning and redeeming points and miles. So, we naturally need to address the question: Can your pet earn miles from travel?

We aren't aware of any airline that rewards miles directly to your pet. However, some airlines reward humans for bringing their best friend along. For instance, JetBlue TrueBlue members get rewarded with 300 bonus points for a pet booking.

Overseas airlines are a bit more generous with rewarding pet travel. For example, Japan Airlines offers travelers 500 bonus miles per flight for their pets.

Meanwhile, the Korean Air Skypets program rewards travelers with stamps for purchasing pet travel. Those stamps can be redeemed for discounts on pet travel, up to a completely free flight for your pet.

You might also earn extra miles if you opt to purchase an additional seat for extra space. For example, Alaska Airlines passengers purchasing a Comfort Seat will earn miles for their own seat and the additional seat.

Likewise, Delta SkyMiles members can earn miles from an extra seat, but you'll need to submit a request for mileage credit after travel. Just note that you won't earn elite-qualifying miles from the extra seat.

Other considerations when flying with a dog

Confirm with the airline that your pet can be carried on your flight. Several types of airline seats don't have adequate storage space for pets, particularly in premium cabins. Plus, many airlines limit how many pets can be carried onto the same flight. So, contact your airline to make a pet reservation and confirm your seat has appropriate storage for a carry-on pet.

Do your research before sedating your pet for travel. The American Veterinary Medical Association recommends against sedating your pet for travel in most cases. And several airlines won't allow you to carry on a pet that's been sedated or tranquilized.

Don't show up at the last minute. Flying with a pet can make air travel even more difficult. You'll potentially need to fill out or show paperwork at check-in, take extra time at security, plus don't forget to work in one last bathroom break for your pet before boarding. Make sure that you arrive at the airport early enough that you have time for all of these steps.

Avoid grooming your pet during travel. Keep in mind that some of your fellow passengers may have pet allergies, and they likely wouldn't have gotten notice that a pet is on their flight. Be considerate and avoid grooming your pet during travels to reduce the amount of dander put off into the airplane cabin.

More resources for traveling with dogs on planes

Different airlines have different policies with respect to traveling with dogs. Here's a closer look at how pet policies vary across airlines:

American Airlines' pet cargo guide

What to know before flying Delta with pets

How to prepare for Southwest pet travel

Understanding the Spirit Airlines pet policy

How United Airlines pet cargo works

If you're considering flying with a dog

Most airlines only let travelers carry on small dogs and cats, and you'll generally have to pay for the privilege of storing them under the seat in front of you.

If you want more space, some airlines let you buy an extra seat that you might be able to use to place your pet's carrier on during the flight. However, your pet generally needs to stay in its carrier the whole trip.

JSX is the only airline we could find that lets travelers carry on a larger dog (up to 79 pounds) and travel outside a carrier. All you need to do is purchase an extra seat for your pet and keep them leashed at all times.