WASHINGTON — It seemed, in retrospect, a bit of a low point — a medium-size dog racing through an airplane at 30,000 feet, spraying diarrhea toward passengers throughout the cabin.
But according to some transportation officials, it was an increasingly typical scene that has stemmed from the growing use of comfort animals on airplanes — a situation that some injured veterans say is making life harder on them.
The airline industry, which has been working to curb the number of comfort animals onboard, has recently found an ally among the nation’s war wounded. Some veterans and service dog organizations say the overuse of untrained dogs, pigs, rodents and amphibians — and, at least once, a small sloth — as emotional support companions has made it difficult for veterans to get acceptance for their properly trained service animals on airplanes and beyond.
“Fortunately and unfortunately, due to this extended war we’ve been having, service dogs have come to the fore to show the amazing benefits they provide medically,” said Jason Haag, a retired Marine captain who runs an organization that matches service dogs to veterans of the post-Sept. 11 wars.
Mr. Haag said he was barred from a flight with his dog because airline workers did not believe it was a legitimate service animal. He said that ill-behaved emotional support animals, which have not undergone the rigorous training that service dogs receive, “make it harder for us to gain access” with dogs when a veteran may not have visible disabilities.
“My dog is specifically task-trained to help with flashbacks,” Mr. Haag said. “I do not have any physical injuries that you can see. It does make it more difficult to say what is my dog is for.”
Over 80 veterans and disability groups recently wrote to Elaine Chao, the secretary of transportation, seeking new rules that would require that emotional support animals be trained if allowed on planes. A number of websites offer “certification” for emotional support animals, for a fee. States and some businesses have begun to fight the proliferation of their use.
Mr. Haag and other groups that train service animals for veterans have become advocates for changes to the law for taking animals on planes, and would like to see local or federal regulations that make animal certification a requirement for public spaces.
“There needs to be standards to hold people accountable,” said Lori Stevens, the founder of Patriot Paws, which works with Texas prisoners to train service dogs for veterans.
One small dog bit a service dog that was lying under a seat at the gate, causing that dog to be spooked and taken out of commission for its veteran owner, she said. Other veterans have drawn unfriendly looks when they take their dogs into public places.
“We have someone who has had 21 brain surgeries, but if you look at him, you can’t see he has a mobile disability,” she said.
Some airlines are sympathetic to the concerns of veterans, and have adapted individual policies to make it harder for those suspected of looking for free rides for their animals.
“Over the last three years, there has been an explosion of emotional support animals, which seems to have coincided with websites that tell people how to get their pets on board and not have to pay for it,” said Sara Nelson, the international president of the Association of Flight Attendants. “We have been very familiar with service animals for a very long time. Those animals are some of the best passengers we have ever had.”
But untrained dogs, like the one with digestive issues, have sullied too many flights.
A few months ago, Ms. Nelson said, a flight attendant needed stitches after being bitten by a dog that was menacing another passenger. A pit bull in a comfort vest rested himself across a row of first-class seats. A duck and a hedgehog made for some miserable middle seating.
“For a while there it looked like we were operating Noah’s Ark,” she said.
The Transportation Department is expected to revise its regulations this year to clarify the definition of a service animal, aimed at reducing the use of support animals on planes. Since 2016, the number of behavior-related service animal problems, “including urinating, defecating or biting,” has increased 84 percent, according to one airline that reports to the agency.
“Initially, when we started cracking down on abuse of emotional services animals, there was a backlash from the disability community and veteran groups,” Ms. Nelson said. “But those groups have come around because their members have been subjected to discriminatory behavior.
“We want clear guidance from the Department of Transportation,” she added. “We need to be matching species that are able to fulfill those service functions and that’s not a peacocks and that’s probably not a sloth.”