Two dogs met in a Detroit Lakes Wal-Mart.
One paced calmly beside Linda Wiedewitsch, a retired police officer who now trains assistance dogs for veterans with post-traumatic stress disorder.
"Can my dog meet your dog?" the other shopper asked. "No, sir," she said. "This is a service dog."
"Well, this is a service dog, too," the other shopper said, as his puppy squirmed and yapped through the muzzle it was wearing.
"No, sir," she said. "It's not."
More service dogs are being trained to help people with a wider range of disabilities than ever before. They can tell with one sniff whether someone with diabetes is having trouble with their blood sugar, or if a child with a life-threatening allergy is about to bite into something dangerous. They can pull wheelchairs, wake veterans from their night terrors, or remind their elderly owners to take their medication.
Many of these conditions are invisible, unlike the dogs in their bright service vests. That can create confusion for businesses unsure of the line between their "No Dogs Allowed" policies and the laws that protect the rights of people with service dogs.
Adding to the confusion, anyone can go online and buy a service dog vest for their pet. That, advocates say, is making it even harder for people with trained service dogs to convince sometimes-skeptical businesses that their dogs are there to do a real job.