Tucked in a corner of the city's sprawling airport, the lounge covers 3,750 square metres, the size of a professional football pitch, and is one of four European hubs for getting your pet from Shanghai to Chicago.
For some, Frankfurt is the final destination however, and "it is always rewarding for us when owners pick up their animals after a long separation," director Alex Heitmann told AFP.
Heitmann, who grew up on a farm, also noted the trust placed by owners in the centre and in Lufthansa, the airline that runs it.
That was clearly the case when Goldfever, the mount of Olympic gold medalist Ludger Beerbaum, flew in at 1 am from a horse show in Sao Paolo.
Goldfever travels with a personal groom, but like all animals at the center, was inspected by one of the 25 vets that work for the German border authority.
Another 60 airline staff also tend to furry travellers – feeding, watering, walking and cleaning up after them.
Lufthansa did not say exactly how much the facility cost, but spokesman Nils Haupt put the sum in double digit millions of euros.
It has separate import and export wings, and a range of cages, stalls and boxes to accommodate the menagerie that has tramped, slithered and swum through since it opened in February.
"Incoming mice", blared a loudspeaker during a visit to the site. Lufthansa, which accounts for around 70 percent of all animal traffic, said it transports 14,000 dogs and cats, 1,500 horses, two million baby chicks and about 4,000 tonnes of tropical fish per year.
Not to mention the masses of Chinese Lugworms that European fishermen are hooked on, the 13 wolves that dropped by on their round trip from Calgary to Siberia, the hippopotamuses that schlepped from Tel Aviv to Manila, or the Red River Hog.
Also known as African Bush Pigs, one flew from Los Angeles to Poland as part of a zoo breeding programme that is a major reason why animals take to the skies.
Another is that some pet owners cannot leave their best friends behind.
Two golden retrievers, a German shepherd from which visitors were warned to keep their distance, and a scared mutt heading to Vienna from Johannesburg were waiting more or less patiently to change planes at Frankfurt.
At around €600 ($800), a round trip dog ticket to New York is not much more than many passengers pay, and includes petting and a medical checkup that even business class does not offer.
Climate controlled chambers range from 15-26 degrees Celsius, so sea lions, baby chicks, reptiles and goldfish avoid thermal shock.
Black lights let vets check on tropical fish without blinding them, while the centre's soft-surfaced cement floor is a nice touch for those whose hooves are killing them.
Animals do have to deal with jet lag however because "they have a day/night rhythm like humans," Heitmann said.
Horses ride standing up in boxes, while zebras have special cages, he noted, and depending on their size are either loaded into the aircraft's belly or get an upgrade to the main deck.
The most tenderly looked after so far were a koala couple that flew from Edinburgh to Salzburg via Frankfurt.
Because handlers must always be present, their cages were strapped in the last row of economy class behind plants to keep curious fellow travellers from spoiling their flight.
Issued boarding cards bearing the names Mr. and Mrs. Koala, their connecting planes were rolled side by side, sparing them even the hike through Frankfurt's maze of terminals.