The Real Rule: Secured Spots, Not a Headcount
AVMA’s transport policy doesn’t set a number of pets per vehicle. It sets a rule per animal: every pet needs its own secured, size-appropriate, ventilated enclosure, or a properly designed safety harness, sized so the animal can stand, turn around, and lie down. No sharing a crate. No riding loose. No tethering pets together as a stand-in for individual restraint.
Flip that rule around and it becomes a math problem instead of a headcount. The number of pets your car can evacuate isn’t “how many animals do we own,” it’s “how many secured spots does this specific vehicle’s cargo floor and seating actually have room for.” That’s the question the rest of this page works through with real numbers.
One Federal Agency Does Publish Numbers, and They Count Containers
USDA’s Animal and Plant Health Inspection Service administers the Animal Welfare Act regulations at 9 CFR part 3, and § 3.15 puts explicit ceilings on how many dogs or cats may ride in one primary enclosure. For a road trip, that is § 3.15(g)(1): “No more than four live dogs or cats, 8 weeks of age or older, that are of comparable size, may be transported in the same primary enclosure when shipped by surface vehicle (including ground and water transportation) or privately owned aircraft, and only if all other requirements of this section are met.” By air the ceiling on adult animals is far tighter, at § 3.15(f)(1): “No more than one live dog or cat, 6 months of age or older, may be transported in the same primary enclosure when shipped via air carrier.” That is paragraph (f)(1) only, and it is worth reading what follows it rather than stopping there: (f)(2) through (f)(4) set separate, looser allowances for puppies and kittens under six months, and (g)(2) does the same on the surface-vehicle side.
How these quotations were checked, and which route settled the characters. All four § 3.15 passages quoted on this page, (g)(1), (f)(1), (e)(1) and the section’s opening sentence, were compared on August 24, 2026 against the Government Publishing Office’s official CFR XML for this section, the January 1, 2025 annual edition of title 9, volume 1, and all four match it character for character. Cornell LII’s rendering of § 3.15 was read the same day as an independent second route and agrees word for word, but it cannot settle characters: LII’s markup leaves a doubled space in front of some of the defined terms it hyperlinks, three of the eleven in this section as we retrieved it, so its opening sentence carries two spaces before the words dog and cat where the CFR has one. eCFR’s own section page is the link we send you to, and it returned the full section text to our retrieval on that date when the request carried an ordinary browser user agent, and eCFR’s current text carries all four passages unchanged from the 2025 annual edition; a request eCFR flags as automated is answered instead by a page headed “Request Access”, which states that programmatic access to the site is limited to its developer APIs. So the character-level route behind these four quotations is GPO’s XML, not eCFR and not LII.
Read what those numbers are counting. Every figure in the section is stated per primary enclosure, never per vehicle, so even taken at face value they never add up to a headcount for your car. § 3.15 also states its own reach in its opening words: “Any person subject to the Animal Welfare regulations (9 CFR parts 1, 2, and 3) must not transport or deliver for transport in commerce a dog or cat unless the following requirements are met”. We are not offering a reading of how far that language goes, and none of this is legal advice. Read § 3.15 at eCFR and take any question about scope, applicability, or who is covered to APHIS rather than to us.
A ceiling is not a recommendation. § 3.15(g)(1) is the most animals a regulated shipper may put in one box, not a suggestion that four should travel in one, and the same section says so in its own space paragraph: § 3.15(e)(1) reads, “Primary enclosures used to transport live dogs and cats must be large enough to ensure that each animal contained in the primary enclosure has enough space to turn about normally while standing, to stand and sit erect, and to lie in a natural position.” That is a test each animal has to pass on its own, which is why a count and a footprint are different questions. Our own recommendation is unchanged: one secured, size-appropriate, ventilated enclosure per animal. Our companion page on whether two cats can share a carrier quotes § 3.15(d)(1) and four more APHIS transport sections in full and works the sharing question through for cats specifically. This page owns the other half, which is a footprint and anchor-point problem rather than a sharing one.
Cargo Dimensions, Sourced Per Vehicle Type
Manufacturer-published cargo dimensions vary a lot by body style, and the differences matter more than most owners expect. Here are three representative vehicles, one per body style, with dimensions pulled from manufacturer specifications:
| Vehicle |
Body style |
Cargo area (seats up) |
Seating capacity |
| Toyota Camry |
Sedan |
Trunk volume: 15.1 cu ft; opening height roughly 18“ (see note below on opening width) |
5 passengers |
| Honda CR-V (6th gen, 2023-2026) |
Compact SUV |
Cargo floor behind 2nd row: 36“L x 44”W at the floor’s widest point; 39.3 cu ft (gas) / 36.3 cu ft (hybrid) |
5 passengers |
| Honda Odyssey |
Minivan |
Behind 3rd row: 32.8 cu ft (Standard cabin) to 38.6 cu ft (Max cabin); behind 2nd row: 86.6 cu ft (Standard cabin) to 91.0 cu ft (Max cabin) |
Up to 8 passengers |
A few things jump out, and one gap is worth being upfront about. We could not verify a reliable trunk opening width for the Camry: Toyota’s own spec pages blocked automated access during this research pass, and the secondary sources that do publish a number disagree with each other by as much as 30 inches (readings ranged from roughly 32“ to 60“ depending on what’s being measured, tail-light-to-tail-light versus wheel-well-to-wheel-well versus the sheet-metal opening itself), so we’re not printing one. What is consistently corroborated across the sources we could check is opening height, roughly 18 inches, and that figure alone turns out to matter more than width for the crates below. The CR-V’s cargo floor is quoted at 44 inches wide, but that’s the floor’s widest point, not the narrower gap between the rear wheel wells that actually constrains a crate’s footprint; our own vehicle-loading guide flags this exact distinction, so treat that 44“ figure as an upper bound, not a guaranteed clearance. We could not find manufacturer-published length and width figures for the Odyssey’s cargo area either, only cubic-foot volume that varies by Standard-cabin versus Max-cabin trim; measure your own Odyssey’s cargo floor before assuming the volume translates to the footprint you need.
Worked Example: 2 Dogs (25 lb, 60 lb) + 2 Cats (9 lb, 12 lb)
Using the same household composition as our go-bag math worked examples, here’s what secured enclosures for this household actually require, sized against Gunner’s own weight guide and CPS-tested carrier specs. One flag before the math: this page assumes CPS-crash-tested Gunner G1 crates for the dogs and Diggs Passenger Carriers for the cats specifically. The go-bag-math page’s gear picks for this same household include the Diggs Revol collapsible crate for the dogs instead, which is not CPS crash-tested, Diggs’ only CPS-certified product is the Passenger Carrier used here for the cats, so the footprint and height numbers below won’t carry over if you’re using Revol crates.
| Animal |
Enclosure |
Footprint |
Height (without / with handles) |
Empty weight |
| Dog #1 (25 lb) |
Gunner G1 Small (up to ~30 lb) |
24.5“L x 18.625”W |
19“H / 20.5”H |
27 lb |
| Dog #2 (60 lb) |
Gunner G1 Intermediate (up to ~70 lb) |
34“L x 23”W |
28.5“H / 30”H |
48 lb |
| Cat #1 (9 lb) |
Diggs Passenger Carrier (up to 18 lb) |
20“L x 10.8”W |
11.5“H |
4.5 lb |
| Cat #2 (12 lb) |
Diggs Passenger Carrier (up to 18 lb) |
20“L x 10.8”W |
11.5“H |
4.5 lb |
Height rules out the Camry’s trunk before width even matters. Both G1 crates in this pairing, 19“ and 28.5“ tall without handles, are taller than the Camry’s roughly 18-inch trunk opening, so neither one can physically pass through it. The two Diggs carriers, at 11.5“ tall, do clear that opening height.
Side by side, the two dog crates need roughly 41.6 inches of bare floor width (18.625“ + 23“). Leaving a few inches of slack per side for anchor straps and door swing pushes that toward the high 40s in inches; we’re estimating that margin ourselves, since the vehicle-loading guide describes the slack qualitatively rather than with an exact figure. For the Camry that width number ends up moot, since the opening height already rules the crates out.
Sedan (Camry): the trunk is out for either dog crate, full stop, since neither clears the roughly 18-inch opening regardless of floor width. Both cat carriers could clear the opening height-wise, but we couldn’t verify a reliable opening-width figure for this vehicle (see the note above), so we’re not promising they’ll fit either; measure your own trunk opening before counting on it. Realistically, plan on both dog crates riding belted on the back seat, using up two seatbelts, with the Camry’s trunk reserved for the cat carriers and other cargo.
Compact SUV (CR-V, 44“ wide cargo floor at its widest point): unlike the Camry, the CR-V’s liftgate opens the full cargo height, so there’s no separate opening-height constraint the way a boxed trunk has, and the 28.5-inch-tall Intermediate crate clears the roughly 36-inch cargo height with room to spare. Width is the real question here, and the raw 44-inch figure overstates it: that number is the floor’s widest point, not the narrower gap between the rear wheel wells that actually constrains a crate’s footprint. Treat a side-by-side fit for these two crates as plausible but unconfirmed until you measure your own CR-V’s wheel-well width; the two cat carriers likely won’t have floor space left over and would ride on a folded or belted rear seat instead.
Minivan (Odyssey): With the third row folded, cargo volume jumps to 86.6-91.0 cu ft depending on Standard versus Max cabin trim, comfortably enough for both dog crates plus both cat carriers with room to spare, and the up-to-8 seating capacity means a family doesn’t have to fold every seat to make it work. This is the clearest case here for why a minivan’s edge over an SUV is cargo-floor math: the same crates that can’t clear a sedan’s trunk opening fit here without a second thought.
The honest takeaway: the same two dog crates that can’t ride in a sedan’s trunk at all fit in a minivan with room left over, while a compact SUV sits in an unresolved middle ground that depends on your specific vehicle’s wheel-well width. Vehicle body style is a real variable in an evacuation plan, and if a sedan is what you have, that’s exactly the kind of gap the “when one car isn’t enough” section below is built to catch.
Stacking Rules: Hard Crates Can, Soft Carriers Cannot
When side-by-side floor space runs out, stacking is the next option, but only for certain crate types, and only done correctly.
Hard, rotomolded crates can be stacked. Gunner Kennels’ own help center answer confirms it: “Yes, you can stack our crates by removing the carry handle(s) of the bottom resting G1™ crate.” Gunner adds a caveat in the same answer: “However, please note that these crates were designed specifically for durability, and not created to be broken down easily.” That cuts both ways: it’s part of why the shell is rigid enough to stack safely, and it means stacking two of them is a real lift, not a quick mid-evacuation rearrange.
Where that quotation comes from, and why the link is an archive. Gunner has removed the help-center article we originally cited. As of August 24, 2026 help.gunner.com does not serve it: an HTTPS request fails at the TLS handshake, a plain HTTP request returns a Cloudflare 409 with the body error code: 1001, and the host’s DNS points at a Zendesk mapping. We checked gunner.com’s own live product, sizing-guide and FAQ pages first, and none of them answers the stacking question, so there is no live page to move the citation to. The wording above is quoted from the Internet Archive capture of December 4, 2024, which we retrieved and confirmed twice, once by fetching the capture and once through the Archive’s availability API. The substance is Gunner’s, the link is an archive, and that is the whole of what we can show you.
Soft-sided carriers cannot be stacked, full stop. A soft carrier like the Diggs Passenger Carrier or the PawsInCar Expandable Carrier is built from lightweight, flexible material with no structural strength to bear another crate’s weight, and nothing belongs underneath one either, since its own floor isn’t rigid enough to hold a stacked load without crushing down onto the animal inside.
What that means for a mixed dog-and-cat household: dog crates are where stacking can free up floor space if you’re using hard, CPS-rated kennels; cat carriers need their own flat, unstacked spot, whether that’s a cleared section of cargo floor or a securely belted back seat.
The Seatbelt and Anchor-Point Constraint Nobody Mentions
Every crate or carrier that rides on a seat instead of the cargo floor uses up a seatbelt. Every crate anchored in the cargo area uses up a tie-down point, and vehicles don’t publish a standard number of cargo tie-downs the way they publish seating capacity, so check your own vehicle for that figure.
Seating capacity is the more consistent number, and it’s a real ceiling: a Camry or CR-V seats 5, an Odyssey up to 8 depending on trim. A family of four evacuating with four pets, two of which need belted back-seat carriers, is already at 6 belts needed in a 5-seat sedan or SUV. The math only works by putting more pets in the cargo area (subject to the footprint limits above) or moving to a higher-capacity vehicle.
This is the constraint that turns “we have room in the trunk” into “we don’t actually have enough secured positions.” Cargo floor space and seatbelt count are two separate ceilings, and a household can hit either one first depending on how many people versus how many pets are riding.
Barrier vs. Crate: Why a Divider Alone Doesn’t Solve This
A cargo barrier or pet divider is common in SUVs and wagons, and it’s tempting to treat it as the multi-pet answer: keep everyone contained to the back, done. It isn’t, under AVMA’s actual rule.
AVMA’s policy calls for each animal to have its own secured, ventilated enclosure or a properly designed harness. A barrier doesn’t do either for an individual animal; it keeps a loose pet (or several) confined to one section of the vehicle, but it doesn’t secure any one of them against sliding, colliding with each other, or being thrown forward in a stop the way a crash-tested crate or harness does. Two dogs loose behind a barrier can still collide with each other on impact, exactly the scenario AVMA’s “no sharing, no riding loose” rule exists to prevent.
Where a barrier does help: as a backup layer behind an already-secured crate, keeping a crate that shifts slightly from sliding forward into the back seat. It’s a supplement to anchoring, not a substitute for the crate or harness itself.
Heat and Airflow in a Packed Car
A cargo area with four crates and carriers wedged in has less airflow around each enclosure than one crate riding alone, and it’s genuinely easier to lose sight of a pet showing early heat-stress signs when the load is packed tight. That’s a real multi-pet consideration, but the underlying heat math doesn’t change with pet count.
Per AVMA and NHTSA’s own heatstroke-prevention data, a parked vehicle’s interior temperature can climb roughly 20°F in the first 10 minutes and 40°F or more within an hour, whole cabin and cargo area alike, packed or empty. No pet should ever be left unattended in a parked vehicle at any outdoor temperature.
With a full load, build in an airflow check as part of your loading order: don’t wedge a crate flush against the vehicle’s interior wall on all sides if you can avoid it, and if you’re stopping for any length of time on a warm day, that’s the moment to actually open a door and check each animal, not just glance through a window.
When One Car Genuinely Isn’t Enough
We did not find a published formula for this in any source we checked, and we’re not going to invent one. But the worked example above points to three honest, checkable triggers:
- Your required crate and carrier footprints don’t fit the cargo floor with clearance for straps and door swing, the way the sedan example above came up short on two dog crates alone.
- Securing every animal would use more seatbelts or cargo tie-down points than your vehicle has, once you also account for every human who needs a belted seat.
- You can’t anchor every enclosure against movement. An unanchored crate, even a 5-star CPS-rated one, isn’t performing anywhere near its tested configuration if it’s free to slide.
If any of those three come up short, that’s the signal for a two-trip plan or a second vehicle, not a reason to let a pet ride loose or double up in a crate built for one. At that point the harder question isn’t math anymore, it’s which pet and which supplies move first. Our triage guide for which pet evacuates first walks through that decision, and our multi-pet go-bag math covers scaling supplies once you know how many animals are riding in which trip.
Vet-Wins Reminders
- A pet with a health condition that makes crate confinement difficult (severe anxiety, certain orthopedic issues, brachycephalic breathing difficulty in a snug enclosure) is a conversation for your veterinarian before an emergency forces the decision, not something to solve with this page’s general math alone.
- Heatstroke signs during transport (heavy panting, drooling, weakness, collapse, seizures) mean stop and get to a veterinarian immediately.
- For suspected poisoning or toxic exposure during a stop, the ASPCA Animal Poison Control Center is available 24/7 at (888) 426-4435 (a consultation fee may apply per the ASPCA’s own page).
How We Chose
The vehicle dimensions above come from manufacturer specifications as compiled by dealer research pages, cited individually to the specific page that actually states each figure, since the manufacturers’ own spec pages blocked direct automated access during this research pass. Where a figure (like the Odyssey’s cargo-area length and width, or the Camry’s trunk opening width) wasn’t published anywhere we could find, or where the secondary sources we could check disagreed sharply with each other, we said so rather than picking one number and presenting it as settled. Crate and carrier specs come from Center for Pet Safety’s certified-product pages, verified individually for each Gunner G1 size rather than assumed from the Intermediate listing alone, plus manufacturer or retailer listings that actually state the dimension or weight figure used, not just a page covering the same product in general. We did not test any of these products or physically load any of these vehicles ourselves, and we say so plainly. Full methodology at /review-methodology.
Once you know how many secured spots your vehicle has, two tools turn that into a plan: the pet emergency supply calculator sizes food, water, and medication to the animals you’re moving, and the pet carrier finder matches a crash-tested crate or carrier to each animal’s weight before you buy. For the anchoring mechanics and full crate shortlist, see vehicle loading and restraints for multiple pets; this page owns the planning math, that page owns the gear.