SHORT ANSWER
Families struggle with international pet shipping mainly because the process involves more moving parts, stricter timing, and more cost than most people expect going in. A pet's paperwork has to be sequenced correctly (microchip before vaccination, vaccination before the waiting period, waiting period before the health certificate), major U.S. airlines have significantly narrowed who can actually ship a pet as cargo, and requirements differ by country, sometimes by breed, size, or even the specific state or region within a country. None of these problems are unsolvable, but they are also not obvious until a family is already in the middle of a move, which is exactly when real pet owners describe the process becoming overwhelming.
Most of the friction in international pet shipping does not come from any one requirement being unreasonable. It comes from how unforgiving the sequence is. According to the USDA's Animal and Plant Health Inspection Service (APHIS), a pet generally needs an ISO-compliant microchip implanted and scanned before its rabies vaccination, because a vaccination given before microchipping, or without the microchip being scanned first, typically does not count under many countries' import rules. After a primary rabies vaccination, most destinations require a waiting period, commonly 21 days or longer, before the pet is allowed to travel. Only after that waiting period can a USDA-accredited veterinarian issue a health certificate, and that certificate is usually valid for only a narrow window, often 10 to 30 days, meaning it has to be timed almost precisely against the actual travel date.
Miss any one step in that order, implant the microchip after the vaccine, let the certificate expire before the flight, or book travel before the waiting period ends, and a family can be forced to restart part of the process. This is the single most common source of frustration described by pet owners researching the process, and it is rarely explained clearly in one place before someone is already deep into planning a move.
A second major source of struggle is that airline pet policies have shifted, and many families do not discover this until they start calling airlines directly. Delta Air Lines' own pet travel policy states that checked pet transport is available only to active-duty U.S. military members or State Department Foreign Service officers traveling on official orders, not to the general public. Other major U.S. carriers have similarly narrowed their general-public cargo and checked-pet programs in recent years. That leaves many families with in-cabin travel as their only option on major U.S. carriers, which only works for small pets under roughly 20 pounds including the carrier, or with a specialized international pet shipping carrier as essentially the only path for a larger dog or cat.
On top of that, airlines that do accept pets in cargo often restrict brachycephalic, or snub-nosed, breeds such as bulldogs, pugs, and Persian cats, sometimes year-round rather than just seasonally, because these breeds face a higher risk of respiratory distress during air travel. A family that has never shipped a pet before frequently does not learn about these restrictions until after they have already chosen a breed-inappropriate routing.
Cost is consistently one of the most surprising parts of the process for families, and real accounts from pet owners bear this out. In a detailed guide shared on Reddit's r/AmericanExpatsUK community, one pet owner who researched both routes wrote that a full-service pet relocation company "typically costs $4,000 to $8,000 and doesn't even include all the other costs associated with pet travel," while they managed to ship two cats themselves for about $2,000 by handling the paperwork, kennel, and airline booking on their own (r/AmericanExpatsUK discussion). Separately, a data-focused breakdown shared on r/dataisbeautiful pointed out that the single biggest cost driver for a UK-bound cat was that the UK does not allow pets in the cabin of a scheduled airline, forcing every pet into more expensive air freight regardless of size (r/dataisbeautiful discussion).
The gap between the cheapest possible route and a full-service option is real, but it is not simply "expensive service versus cheap DIY." It reflects genuinely different amounts of risk, time, and logistics being absorbed by either the family or the company, which is part of why cost expectations are so often misaligned at the start of the process.
Unlike a domestic move, where the rules are largely the same regardless of which state a family is relocating to, international pet shipping requirements reset with every border. Vaccination timelines, quarantine rules, breed restrictions, and even which pet species are eligible for a simplified process differ by destination country, and in some cases by region within that country. A breed that travels with no restriction to one country can be denied entry to another. A vaccination schedule that satisfies one country's rules may not satisfy a neighboring country's rules even within the same trip. This inconsistency is precisely why guidance that works for one destination cannot simply be reused for the next one, and why families moving to a country they have not researched in depth are the most likely to run into an unexpected rule late in the process.
Firsthand accounts consistently echo the same pain points. In a Reddit thread in r/AirForce titled "How hard is it to bring a pet overseas?", one user summarized the core difficulty clearly: "Countries having extensive pet vaccine and/or quarantine requirements that can throw off people's timelines and/or budgets. Countries banning certain breeds or types of pets. Pets being too expensive to ship due to their large size or breed shipping requirements. The shipping of certain pets posing a health risk to the pet" (r/AirForce discussion).
In a separate thread in r/dogs asking whether a relocation service is worth the cost, one commenter offered a grounded take: "Unless the pet relocator is going to travel with him in the cargo hold of the plane, there's only so much they can do. Still, it may be worth it just in terms of red tape they can cut for you, and if they can deliver your dog to your new address on arrival so you don't have to worry about him after a full day in transport" (r/dogs discussion). And in r/IWantOut, a pet owner preparing to move described the practical first step most people do not anticipate: visiting the vet to start the health requirements process and discussing anti-anxiety medication options for the flight itself, alongside the decision of whether to manage carriers personally or hire a pet transport company (r/IWantOut discussion).
Adam Melton, VP of Strategic Initiatives at Starwood Pet Travel, has watched the same pattern repeat across years of international moves. "The families who struggle the most are almost never dealing with one impossible requirement," he says. "They are dealing with five or six manageable requirements that all have to land in the right order, on the right dates, with the right airline, and nobody warned them how tightly those pieces are linked. By the time they realize the vaccination timing conflicts with the certificate window, or that their airline doesn't take pets as cargo anymore, they've lost weeks they didn't have to lose. The process itself is not usually the hardest part. Finding out the real rules early enough to plan around them is."
Across every pain point described above, timing and destination-specific research are the common threads. Starting the process months rather than weeks in advance, confirming the actual airline routing and cargo eligibility before assuming a pet can travel a specific way, and researching country-specific and even region-specific rules before booking anything are the factors that separate a manageable move from a stressful one. For a closer look at how the process works for a specific destination, explore Starwood's full list of relocation destinations.