Updated September 15, 2026first published December 14, 2021Rewritten in full against the current regulations
Flying with a large service dog is not the same problem as flying with a small one. The law that covers your flight is the same either way. The place your dog has to physically fit is not.
What it was actually like, once
Mr Big is a hundred and five pounds. We flew DFW to Fargo and back, and he did not fit in the foot space. That was obvious to me and it was obvious to the cabin crew the moment they looked at him.
When I booked I used the accommodations section of the reservation to say I was flying with a large service dog and would need the seat beside me for him. I picked a middle seat with empty seats on either side. I assumed filling in that section put the booking into some kind of review, and that somebody would look at it.
Nobody did. No call, no email, no question, nothing. The first person at that airline who dealt with my dog was standing at the gate.
One thing to say plainly before the rest of this page: my flight was before 11 January 2021. The rule that governs your flight is not the rule that governed mine, and I have said so where it matters. Some of what happened to us is exactly what the current rule now sets out to prevent.
Almost everything written about this subject online is either out of date or was written to sell you something. The rules changed on 11 January 2021, and a great deal of advice still circulating was true before that date and is false now. If you follow it, you will be turned away at the gate holding a document nobody asked for.
Here is what the rule actually says, section by section, with the size question answered properly.
Read this first: the one rule that changed everything
The Department of Transportation rewrote the service animal rule in December 2020. The final rule took effect on 11 January 2021, and it did two things.
It narrowed what counts as a service animal on a flight to a dog, individually trained to do work or perform tasks. And it removed emotional support animals from the protection of the Air Carrier Access Act entirely.
Since that date, an emotional support animal flies as a pet. It pays a pet fee, it meets the carrier’s pet rules, and for a large dog that usually means the cargo hold or no flight at all.
If you have been told to buy an ESA letter for a flight, you have been sold a document that has done nothing at an airport since January 2021.
1. Your flight is governed by a different law than the store
The Americans with Disabilities Act does not govern commercial flights. The Air Carrier Access Act does, through its regulations at 14 CFR Part 382.
This catches people out constantly, because the two laws do not match.
| ADA | Air Carrier Access Act | |
|---|---|---|
| Where it applies | Shops, restaurants, hotels | Aircraft and the airline’s areas of the airport |
| Paperwork allowed | None | Two DOT forms |
| Advance notice allowed | None | Up to 48 hours |
| Species | Dogs, plus miniature horses | Dogs only |
The two questions a shop may ask you are not the questions an airline may ask you. An airline may require a form in advance. A restaurant may not. Knowing which building you are standing in tells you which rule applies. A cruise ship is a different building again, and a service dog on a cruise ship falls under its own federal rule.
If a business on the ground refuses your dog, that is an ADA problem and a different process entirely. We cover that in what to do if your service dog is denied access.
2. Only a trained dog counts, and the definition is short
14 CFR 382.3 defines a service animal as:
A dog, regardless of breed or type, that is individually trained to do work or perform tasks for the benefit of a qualified individual with a disability, including a physical, sensory, psychiatric, intellectual, or other mental disability.
The Department of Transportation states plainly that emotional support animals, comfort animals, companionship animals, and service animals in training are not service animals for the purposes of this rule.
Read the definition closely. It turns on training to do a task, not on how the dog makes you feel. A dog that is wonderful company on a difficult flight is doing something real and valuable, and it is not what this rule protects. A dog that has been trained to retrieve medication, interrupt a dissociative episode, brace a handler through turbulence or alert to a drop in blood sugar is doing work, and it is.
Note also the first three words after “dog”: regardless of breed or type. That phrase is in the definition on purpose, and we come back to it at point 10.
If you are still working out which side of this line you are on, emotional support animal vs service dog sets the two apart properly.
3. There are exactly two forms, and both are free
14 CFR 382.75 is the documentation section, and it is unusually generous to travelers because it is a closed list.
An airline may require:
- The U.S. Department of Transportation Service Animal Air Transportation Form — published here by DOT. It attests to your dog’s health, behavior and training.
- For a flight scheduled to take eight hours or more, the DOT Service Animal Relief Attestation Form — also published by DOT. It attests that your dog will not need to relieve itself, or can do so in a way that does not create a health or sanitation problem.
And then § 382.75(c) closes the door: a carrier may not require documentation beyond those two forms, except where it needs to comply with the requirements of a federal agency, a U.S. territory, or a foreign government.
§ 382.75(d) requires U.S. carriers to make copies of the forms available at every airport they serve. § 382.75(e) requires carriers with websites to publish them in accessible formats and to mail you a copy if you ask.
Name the incentive
Both forms are written by the federal government, published by the federal government, and cost nothing. You fill them in yourself. There is no agency that approves them, no registry that records them, and no body that certifies them.
An entire industry exists to sell travelers documents for flights. It survived the 2021 rule change by changing its wording rather than its product. The incentive is obvious once you look for it: a free government form generates no revenue, and a letter does.
A form the government publishes for free is a rule. A letter someone sells you is a product.
The same test sorts out most of the paperwork you will be offered. It is the flight version of the one we apply to registries in how to identify a fake service dog: a scam sells you a document, a right comes from a statute you can read yourself.
4. Forty-eight hours is the outside limit on advance notice
§ 382.75(g) ties the airline’s notice window to when you booked.
| When you booked | What the airline may require |
|---|---|
| 48 hours or more before departure | Up to 48 hours advance submission of the forms |
| Less than 48 hours before departure | No advance notice; forms may be completed at the gate |
And § 382.75(h) is the paragraph worth remembering if your travel plans fall apart. If you miss the advance deadline, the carrier must still make reasonable efforts to accommodate you, so long as doing so does not delay the flight.
Missing the window is not automatically a refusal. It is worth saying so out loud at the counter, because it is not always the first thing you will be told.
§ 382.76 adds one more protection: an airline may not force you to check in physically at the airport, rather than online, just because you are traveling with a service animal.
5. Your dog rides on your lap or in your foot space
This is where the large-dog question finally gets a real answer, and the answer lives in 14 CFR 382.77(a):
You must permit a service animal to accompany a passenger with a disability on the passenger’s lap or in the passenger’s foot space, unless this location and placement would: (1) Be inconsistent with safety requirements set by the FAA or the foreign carrier’s government; or (2) Encroach into another passenger’s space.
Two things follow from that sentence.
The first is that your foot space is your entitlement, not a favor. The airline must permit your dog to occupy it.
The second is the limit that actually affects big dogs: encroaching into another passenger’s space. A Great Dane or a large mobility dog settled in a down-stay will not always fit inside one economy foot well. That is not a failure of training and it is not a rule against your dog. It is a measurement problem, and the rule anticipates it.
A measurement problem, measured
Here is what that looks like with a real dog in it. A hundred and five pound labrador mix, lying down, is longer than the foot well of an economy seat. It was not close. When the cabin crew told me he would have to settle at my feet, I could not put my own feet where feet are supposed to go.
Nobody had to argue about it. Everyone standing there could see it.
That is worth knowing before you book, because it means the conversation you are going to have is not about whether your dog is well trained. Mine was flawless and it changed nothing about the arithmetic. If your dog is large enough that you are reading this page, plan for the foot space not working and read the next point carefully.
Which brings us to the two paragraphs that most articles about flying with a large service dog leave out.
6. If your dog does not fit, the airline owes you a move first
14 CFR 382.77(b):
Before refusing to transport a large service animal that cannot be accommodated on the passenger’s lap or in the passenger’s foot space without encroaching into another passenger’s space, you must offer the passenger the opportunity to move with the animal to another seat location within the same class of service, if available on the aircraft, where the animal can be accommodated.
Read that as a sequence, because it is one. A refusal is not the airline’s first move. It is the last one. Before it can refuse, it must offer you a different seat in the same class of service, if a workable seat exists on that aircraft.
Same class of service matters. The airline is not required to move you into a better cabin, and it is not required to reseat other passengers to make room for your dog, except where the priority seating rules in Subpart F apply.
But bulkhead rows and window seats in the same cabin often solve the problem outright, and § 382.77(b) means you can ask for one as a matter of regulation rather than as a favor. If you are told at the gate that your dog is simply too big, this is the paragraph to raise, by number.
I did not know this paragraph existed
When the crew came to set up for departure, they did not want him on the plane. I was told there was no room, and that I could either take another flight or put him in cargo.
I said no. Nicely, but no.
I had no idea it was mandatory for them to accommodate our seating at all. I thought they were being awfully good about it.
Read that again, because it is why this section is written the way it is. I was standing at a gate being offered the two things that come after a refusal, by people who had skipped the step in between, and I was grateful to them. I did not know there was a step in between. Nothing in the booking process told me, nobody at the gate mentioned it, and I had not read the regulation because it had not occurred to me that there was one to read.
If you take one thing off this page, take this: the seat move is not a favor and it is not the airline being nice to you. It comes before a refusal, and you are allowed to say the number out loud.
What they actually did, and why I would not ask for it now
We got on the plane. The crew moved us to the emergency exit row, because that was where there was room for him to lie down. They did not want him on a seat. He turned to face the exit, put his head on my feet, and was faultless the whole way.
I have since learned that this was probably not something they should have done.
The Department of Transportation is explicit that a service animal cannot block a space that has to stay clear for safety, and it gives access to an emergency exit as its example. The FAA’s exit seating rules require anyone in that row to be able to get out through that exit quickly and to help others do the same. A hundred pound dog stretched across that floor is precisely the situation both of those rules are written about.
So do not read my flight as a tip. The crew were improvising, kindly, because nobody had done the thing the regulation actually provides for. Ask for the seat move under 382.77(b). Do not ask for an exit row. A bulkhead row gives you the same floor space without asking a crew to choose between your dog and an evacuation.
7. If nothing in the cabin works, cargo is free — and you may still say no
14 CFR 382.77(c) covers the case where no seat on that aircraft will work:
If there are no alternatives available to enable the passenger to travel with the service animal in the cabin of the scheduled flight, you must offer the passenger the opportunity to transport the service animal in the cargo hold free of charge or travel on a later flight to the extent there is space available on a later flight.
Two offers, and they are the airline’s obligation, not its generosity. If your dog goes below, it goes below at no charge. And the later flight is a genuine alternative you are entitled to be offered, not a consolation.
It would be dishonest to present the cargo option as neutral. For many handlers it is not a real option at all — a dog that performs medical alert or psychiatric work is doing nothing for you in a cargo hold, and separation carries risk for the dog and removes the assistance you traveled with. Plenty of experienced handlers will take the later flight every time.
The point is that both offers must be made to you, and the choice between them is yours. An airline that jumps straight to refusal has skipped two steps the regulation requires.
Where I stand on cargo, since I have been offered it
I should say that in the first person, because I am one of those handlers and I was offered the choice standing at a gate.
I would take the later flight. Always.
No living soul deserves to ride in cargo. Not a dog, not a cat, not a horse, not a bird. It is cold, it is lonely, the pressure is wrong, and it hurts them. That they cannot tell you so does not mean they are not feeling it.
And while I am here, something to the people who put a vest on a pet so it does not have to fly in the hold. I understand exactly why you do it. I am not going to pretend otherwise. A cargo hold is no place for an animal you love, and the alternative is leaving them behind.
But please make another arrangement. Every untrained dog that goes through a cabin as a service dog makes it harder for the next real team through that gate, and we are only trying to get from A to B without the whole thing coming apart on us.
8. Two dogs is the ceiling
14 CFR 382.74 sets the limit: a carrier is not required to accept more than two service animals for a single passenger.
For most handlers this never comes up. It matters if you are traveling with a dog that is retiring and a successor dog in the same period — a situation we look at in retiring a service dog — and it is worth confirming with the airline well before the 48-hour window in that case.
9. Leashed, harnessed or tethered — the whole time
14 CFR 382.73(b) allows a carrier to require that a service animal be harnessed, leashed or otherwise tethered at all times by its handler, both on the aircraft and in the parts of the airport the carrier owns, leases or controls.
This is one of the few places where the flight rule and the ground rule broadly agree, and we go through the equipment question in is a leash necessary for service dogs.
For a large dog, the practical note is that a tether long enough to let your dog settle across your foot space is doing two jobs at once — compliance and comfort — and a short traffic lead is not.
10. Behavior can get your dog refused. Breed cannot.
14 CFR 382.79(a) lists the grounds for refusing a service animal. There are four, and the two that come up in practice are:
- The animal poses a direct threat to the health or safety of others
- The animal causes a significant disruption in the cabin or gate area, or its behavior indicates it has not been trained to behave properly in public — running loose, repeated barking or growling, biting, jumping on people, or relieving itself in the cabin or gate area
Now the safeguard. § 382.79(b) and § 382.79(c) require that any such decision be made through an individualized assessment, independent of the dog’s breed or type, based on reasonable judgment and the best available objective evidence.
That phrase does real work. A refusal has to be about your dog’s actual conduct, assessed on the day, on the evidence. It cannot be about what your dog looks like. This is the same principle we set out in can a pit bull be a service dog, and on a flight it is written directly into the regulation twice.
What the regulation does not cover: the other passengers
The regulation protected him. The passengers did not.
On that flight I could hear people around us saying he looks like a pit bull and how can they let a dog in the cabin with us. Not to me. Near me, which is its own particular thing. He is a chocolate lab mix with a broad head, and what that costs us is in can a pit bull be a service dog.
Nobody sat in our row for the entire flight.
The gate agents had not been thrilled with us either. The cabin crew were considerably better and still managed to leave me feeling we were putting them out somehow.
I am not telling you this to put you off flying. I am telling you because it is the part nobody warns you about, and because there is one thing that reliably works, and it is not paperwork and it is not explaining yourself. His behavior and his demeanor win, every time. Him, lying quietly with his head on my feet, while a cabin full of people decided what they thought.
§ 382.79(d) goes further: a carrier must not refuse transport if there are means short of refusal that would mitigate the problem.
And it cannot be about another passenger either
This is the part that gets left out everywhere, and it is the one I would want in your hand at a gate.
Look at the four grounds in 382.79(a) again. Every one of them is about the dog, or about your forms. Another passenger is not on that list.
Read the disruption ground closely as well, because the wording is doing work. It is not that there was a disruption. It is that the animal causes a significant disruption, or that the animal’s own behavior shows it has not been trained to behave properly in public. A passenger who objects loudly to your dog is a disruption that passenger caused. It is not objective evidence about your dog, and 382.79(b) and (c) require the assessment to rest on the best available objective evidence, individually, about the animal.
So none of this is a lawful ground to refuse you. Somebody says they are allergic. Somebody says your dog looks like a pit bull. Somebody is frightened of dogs, or does not think a dog belongs in a cabin, or would simply rather not sit near one. Somebody makes a scene about it at the gate, on the jetway, or in the aisle after boarding.
An allergy is a real thing and the person who has one deserves to be looked after. But that is a problem for the airline to solve between two passengers, and the paragraph directly above says the carrier must not refuse the animal where means short of refusal would mitigate it. Moving that passenger is a means short of refusal. So is moving you.
What a refusal cannot be is your dog carrying the consequences of somebody else’s behavior. If that is what is happening, it is the moment to ask for the written explanation in the next section, because a written statement naming which of the four grounds applied is very hard to produce when the honest answer is that a stranger complained.
11. A refusal has to be put in writing
14 CFR 382.79(e) requires a carrier that refuses to transport a service animal to give the passenger a written explanation, either at the airport or within 10 calendar days, specifying the basis for the decision.
Ask for it. Ask for it at the gate, by name, and note the time you asked.
A written statement of the specific regulatory ground is very hard to produce for a decision that was actually made on the dog’s appearance, and it is the document any later complaint to the Department of Transportation will turn on.
Before you fly: the practical part
The regulation settles your rights. It does not settle the logistics, and with a large dog the logistics take more planning than they do with a small one.
Relief areas. 14 CFR 382.51(a)(5) requires carriers, working with the airport operator and in consultation with local service animal training organizations, to provide animal relief areas for service animals traveling on their flights. What the rule does not do is standardize where those areas are. Some are past security, some are not, and a connection that requires leaving the secure area is a very different journey than one that does not. Look up the specific relief areas at your departure, connection and arrival airports before you book, not on the day.
What the relief areas are actually like
I have used them, and I want to be more useful about this than the rule is.
In my experience there is roughly one per hub, it is past security, and it is tucked somewhere you will not find without asking an employee for directions. They have been, for the most part, completely missable. On the Fargo trip our flight was delayed, so I left the gate to go and find one, and it turned out to be a long way from where we were sitting.
What you find when you get there is usually a small tiled room. It looks like an operating theater and it smells considerably worse. Tile floor, maybe some pee pads. That is it. One in Chicago had a fire hydrant in it, which got aimed at a great deal, and which I still think is funny.
And here is what made it useless to me on the day. Mr Big is house-trained. He is not pee pad trained. Asking a house-trained dog to relieve himself on a tiled floor indoors is asking him to do the exact thing you spent years teaching him never to do. He would not, and I do not blame him.
Relieve your dog before you get to the airport. Once you are on airport property there is nowhere that resembles their own environment at all. Getting there is its own problem if you use a rideshare, and a driver refusing your dog at the curb runs on the ADA, not on the air travel rules below. A bus or train to the airport runs on a third set of rules again.
And think for a second about what we are actually asking of them out on the airport side. Pavement. Hot pavement in July, or frozen pavement in January with their paws sticking to it. Nothing that smells like anywhere they have ever been. It is undignified, and they do it because we ask them to. Somebody should say that out loud.
Feeding. A lighter meal before a flight is sensible for a dog that will be settled for hours, but there is no reason to guess at it. Your dog’s normal portion, judged on body condition rather than on the label, is the right starting point — see how much to feed a service dog. Water is a different matter and should not be restricted.
Exercise. A long walk before you leave for the airport helps a dog settle. It also lets you confirm your dog has relieved itself before you enter a building it will be inside for several hours.
Measure the foot space. Airline seat maps publish seat pitch. If you know your dog’s length in a down-stay, you can often tell before you book which rows will work — and point 6 gives you the language to ask for one of them.
What is in my carry-on
None of this is in the regulation. All of it is from having done it.
A small bag of his food, kibble or canned. A collapsible water dish. A bottle of water, for him rather than for you. Poop bags. Baby wipes. A clean washrag. A few small ziplock sandwich bags. A couple of anti-diarrhea tablets. And pee pads, even though mine would not use one, because the day you need one is not the day to find out.
And his favorite toy, or whatever treat he works for.
That last one is not a supply, and it is the one I would not leave behind. An airport has nothing in it that smells or sounds or feels like home. One thing that does is worth the space in your bag.
Accidents happen. So does motion sickness. Neither is a training failure, and both are a great deal worse at thirty thousand feet with nothing useful in your bag.
One more, and it is not something you can pack. Expect a few people to be rude. It does not always happen and it happens more often than you would think. When someone asks a question that is clearly none of their business, you are allowed to decline to answer it. Somebody being rude enough to ask does not make it any of their business. Be polite, and let your dog do the rest.
Flying internationally is a separate problem
Everything above is the U.S. rule. It applies to flights within the United States, and to foreign carriers on flights to and from the United States, in the ways Part 382 sets out.
It does not tell you whether the country you are landing in will let your dog in. That is a question of import rules, vaccination and titer requirements, quarantine and national assistance dog law, and those are answered by the destination, not by your airline — often months in advance.
We cover the process in traveling internationally with a service dog, and the legal position on the far side in does the ADA apply in other countries. The short version: your U.S. rights end at the aircraft door on the return leg, and the destination country’s rules were never bound by them at all.
We do not fly any more, and that is an answer too
Mr Big has had a leg amputated since that flight, and we have not been on a plane since.
I thought about it seriously at around six months after the surgery, when he was a great deal more agile than he is now, and I decided against it. It is not that he is a bad flyer. He is a superb flyer. It is the walking. An airport is an enormous amount of ground to cover, a delay makes it more, and he handles stress so well that he will not tell you when he has had enough. These days going outside twice a day is a few steps, and it is work.
So we drive.
We have taken a lot of road trips since, and I will be honest with you: they are better. We stop when we want to. He gets rest areas, and he remembers them, and his eyes light up when he recognizes one he has been to before. We stop at Buc-ee’s or a McDonald’s and he gets his favorite thing, a cheeseburger, no pickle.
It takes longer and we enjoy it more.
I am putting that at the bottom of a page about your right to fly because both things are true at the same time. The regulation is real, it is more protective than most people believe, and you should use every line of it. And there may come a point with your own dog where the right answer is not to make him do it, and choosing that is not giving anything up.
Know what you are owed. Then decide what you are willing to ask of him.
Frequently asked questions
Can service dogs ride on airplanes?
Yes. On US airlines a trained service dog rides in the cabin, free of charge, on your lap or in your foot space. Under 14 CFR 382.3 that means a dog, regardless of breed or type, individually trained to do work or perform tasks for a person with a disability. The airline may ask for the DOT Service Animal Air Transportation Form, plus the Relief Attestation Form on flights of eight hours or more. Airlines are not required to treat emotional support animals, or any animal other than a dog, as service animals.
Can I fly with a large service dog in the cabin?
Yes. Under 14 CFR 382.77(a) the airline must permit your service dog to travel on your lap or in your foot space, and the only limits are FAA safety requirements and encroaching into another passenger’s space. If your dog is too large for the foot space, the airline must first offer you another seat in the same class of service before it may refuse to carry the dog.
What forms do I need to fly with a service dog?
There are two, both free from the Department of Transportation. The DOT Service Animal Air Transportation Form covers your dog’s health, behavior and training, and an airline may require it on any flight. The DOT Service Animal Relief Attestation Form applies only to flights scheduled to take eight hours or more. Under 14 CFR 382.75(c), a carrier may not demand documentation beyond those two.
What does Delta require for a service dog?
Delta’s own service animal page asks for the DOT Service Animal Air Transportation Form on every flight, and the Relief Attestation Form on flights of eight hours or more, submitted with a service request at least 48 hours before departure. It accepts dogs only, a maximum of two, fully vaccinated and at least four months old, on your lap or in your foot space. If you booked less than 48 hours before departure, 14 CFR 382.75(g)(3) says no airline may require advance notice from you.
What does Southwest require for a service dog?
Southwest’s help center asks you to show a completed DOT Service Animal Air Transportation Form, printed or digital, at the ticket counter or gate on your day of travel. It accepts dogs only. Your dog sits at your feet, or in your lap if it is no larger than a child under two, and you may sit anywhere except an emergency exit seat. If you need a bulkhead or other specific seat because of your dog, Southwest asks you to call no later than 24 hours before departure.
Does my emotional support animal still fly free?
No. The Department of Transportation removed emotional support animals from the Air Carrier Access Act in a rule that took effect on 11 January 2021. Since that date an emotional support animal flies as a pet, under the carrier’s own pet policy and pet fees, and for a large dog that generally means the cargo hold rather than the cabin.
How far in advance do I have to tell the airline?
It depends on when you booked. If you reserved 48 hours or more before departure, the airline may require your forms up to 48 hours in advance. If you booked inside 48 hours, it may not require advance notice at all and must let you complete the forms at the departure gate. Missing the deadline is not an automatic refusal.
Do airlines charge for a service dog?
No. A trained service dog travels in the cabin at no charge, and there is no fee for the DOT forms. If no cabin seating works and the dog must travel in the cargo hold under 14 CFR 382.77(c), that carriage is also free of charge. Any fee being quoted to you is a pet fee, which means the animal is not being treated as a service animal.
Can an airline refuse my service dog because of its breed?
No. Under 14 CFR 382.79(b) and (c), a refusal based on a direct threat or on misbehavior must rest on an individualized assessment, independent of the dog’s breed or type, using the best available objective evidence. The definition of a service animal in 14 CFR 382.3 also says regardless of breed or type. A refusal must be about what your dog actually did.
What happens if my service dog is too big for the foot space?
The airline must offer you the chance to move with your dog to another seat in the same class of service where the dog can be accommodated, if such a seat is available on that aircraft. It is not required to move other passengers or to upgrade you. Only if no cabin option exists may it move to the options in 14 CFR 382.77(c).
Will my service dog have to fly in cargo?
Only if nothing in the cabin works, and even then it is an offer rather than a requirement. Under 14 CFR 382.77(c) the airline must offer either free carriage in the cargo hold or travel on a later flight with space available. The choice between those two belongs to you, and many handlers decline cargo because a dog in the hold cannot do the work it is trained to do.
How do I complain if an airline gets this wrong?
Ask for the written explanation that 14 CFR 382.79(e) requires, which must come at the airport or within 10 calendar days. Every airline must also have a Complaints Resolution Official available, and you can escalate to the Department of Transportation’s Aviation Consumer Protection Division. Keep the flight number, the times, and the names of the staff involved.
The short version
The rules for flying with a large service dog are more protective than most people believe and more specific than most articles admit.
Your dog rides in your foot space by right. If it does not fit, a seat change comes before a refusal. If no seat works, free cargo carriage or a later flight comes before a refusal. A refusal has to be individualized, breed-neutral, and put in writing.
The paperwork is two free government forms and nothing else.
Everything beyond that which you are being asked to buy is a product, not a requirement.
Sources: 14 CFR 382.3, 14 CFR 382.51, 14 CFR 382.73, 14 CFR 382.74, 14 CFR 382.75, 14 CFR 382.76, 14 CFR 382.77, 14 CFR 382.79, DOT Final Service Animal Rule, 85 FR 79774, DOT Service Animals guidance, Delta Air Lines, Trained Service Animals, Southwest Airlines, Traveling with a trained service dog.