The days of tying Fido to the lamppost might be waning. 

That's because unscrupulous owners are bogusly outfitting their pets in service vests and gear so they're welcomed into restaurants, stores and other places that normally prohibit animals. It's a practice that's dangerous, veterinarians say, and undermines the intent of the Americans with Disabilities Act, or ADA.

Dr. Brenda Johansen, a practitioner in Waukesha, Wis., relayed a recent encounter she and her children had with a dog wearing a service vest.

“I was at a Target and saw a service dog with a woman in a wheelchair coming our way," Johansen wrote on a message board the Veterinary Information Network (VIN), an online community for the profession. "My three kids love dogs, so as she approached, I told them to all hang on to the cart, and no one was allowed to touch the dog as it was working. As they approached, the dog lunged at us — not an aggressive lunge, just a ‘hey, pet me!’ lunge."

"If that was a service dog, I’ll eat my hat," she added.

For two decades, federal law has mandated that service dogs can accompany people with disabilities as they go about their everyday lives, even flying in the cabin of aircraft. According to the ADA, dogs qualify as service animals when the owner has a documented disability, the dog is trained to perform a task to alleviate that disability and the animal's presence in public does not alter the environment for others.

But there is no government certification for service dogs, and owners aren't required to carry proof of a service dog's training. Obtaining collars, vests and tags printed with "service dog" are sold by hundreds of online companies, no questions asked.

That lack of oversight, critics say, makes it easy for owners to fraudulently pass off their pets as service dogs. While such deceit might seem harmless, each time a phony service dog acts out in public, it chips away at a system that’s intended to aid the disabled. What's more, misidentifying a dog as a service animal can give the public a false sense of security about the canine's temperament and behavior. "When these untrained dogs are in places they shouldn't be, a lot of problems can occur," wrote Dr. Karen Gillum of Galloway, Ohio, in the VIN discussion.

Some veterinarians wonder how to determine whether service dogs are bona fide, especially when some practices offer them discounted medical care. Others question whether the veterinary profession in general should be involved in weeding out phony service animals.

Dr. Melissa Nixon, a disabled veterinarian who's been aided by three service dogs, doesn't think so.

"It’s not our problem to solve," she opined.

Nixon agrees that a lack of federal oversight of service-dog training leaves room for abuse. At the same time, it allows disabled people to easily obtain the working gear they need for their service animals, she said. 

Officials with the U.S. Department of Justice (DOJ), which administers the ADA, explain that service dog training isn't federally regulated so that owners can self-train their dogs to perform individualized and unique tasks. Putting a dog through a training school — whether it's to help people with vision impairments, seizure disorders or aiding those with mobility or psychiatric disabilities — can cost upwards of $20,000 and would price out much of the disabled population.

Another hurdle to overseeing the legitimacy of service dogs: An owner's medical records and dog training documents are private.

Still, a push remains to develop some regulation and oversight of service dogs. Dr. Skip Fix, a veterinarian in Houston, said he was "shocked" to see how many service dogs were on his recent flight to California. Some, he suspects, were imposters.

"I'm all for legitimate service dogs and feel they do help folks, but just like handicapped parking stickers for cars I think this is being abused," he wrote on VIN. "There does need to be some licensing body for them."

Dr. Greg Nutt in Canton, Ga., agrees: "How many people in the general population are capable of providing specialty training to their service dog? I doubt very many. Honestly, how many people even do basic obedience?"

Identifying a licensing body would be a problem, said Debbie Genereux, CVT and co-owner of Animal Diagnostic and Wellness Center in Temple Terrace, Fla.

Genereux, whose Pekingese is trained to compensate for her owner's hearing impairment, said she receives calls from owners inquiring how their pets can become service dogs simply so they can travel with them. That said, she doesn't see how a government agency could impose regulations on service animals without causing hardship for those who truly need them.

“There’s so many different types of services that are provided, and the training needs to be very different for all of those things ... I don’t think you could have a situation where there’s one entity to take care of all of it,” she said. “... To be firmer on these things, you’re going to infringe on the right of the (disabled) person."

When it comes to fake service dogs, Genereux believes it's best to just "let it go."

Nixon adds: “I don't personally know what the solution is to the fake service dogs, but limiting access to vests and other equipment for legitimate teams is not the answer."

Not everyone wants to look the other way. 

A group called Canine Companions for Independence (CCI) is petitioning the DOJ to ban the online sale of service dog products.

The organization, which breeds and trains service dogs, says the proliferation of imposters makes it difficult for those who really need service dogs to gain access to public facilities.

"... Some misguided people outfit their untrained family dogs with fraudulent assistance dog credentials to get them the same all-access pass," a CCI news release said. "When these dogs are in places they shouldn't be, a lot of problems can occur."

Nixon fears the unintended consequences of creating restrictions on service gear or a certification requirement.

“What I would hate to see happen is to create another whole level of regulatory hoops for the disabled to jump through,” Nixon said. “Any time we create something where the government says ‘you have to have a piece of paper,’ unethical people are going to step in and say, ‘How much could we charge for this?’

“My feeling ultimately is if a dog is behaving in public appropriately, let it be,” she added. “For that one bona fide disabled person to once again have the door slammed in their face because someone doesn’t think it looks like a service dog — that is what the ADA is trying to prevent.”