Physical and mobility assistance dogs are by very definition larger dogs who can brace or even lift a person who may have physical limitations including handlers with MS, CP, CRPS, vertigo and many other conditions.
These dogs may provide physical balance and support, which if distracted by a well-meaning bystander can cause the dog to turn his head and knock over or throw his handler off balance.
Some dogs may be a bit smaller if they sit in a wheelchair with their handler and need to assist with fine motor skills. So not all service dogs are 70lb retrievers. There are in fact many breeds and combinations of breeds that make excellent service dog.
Some unusual breeds include Rhodesian Ridgebacks and Cavs, which can serve as excellent emotional support and companion dogs for someone with an anxiety disorder or condition. Great Danes and mixes can be wonderful for mobility and balance dogs. Even three-legged dogs can be wonderful as emotional support dogs or used for other purposes including scent work, such as a diabetic alert dogs.
Regardless of the type of breed, EVERY SERVICE DOG MUST BE PERFECTLY WELL-BEHAVED AND HOUSEBROKEN. Any dog who appears to be a danger to itself or to others, or who appears to be aggressive in any way to the general public should be reported to the management at the facility in which the dog is located. Real service dogs will typically be exceptionally well-behaved to the point that you probably won’t even notice that they are at the restaurant or public place. An out of control dog is almost always a counterfeit service dog.
Unfortunately, some people think they are immune from the law and from moral and social conscience. They will bring an ill-behaved pet, with a fake vest and ID, to a hotel, onto a plane, into a shopping mall or other pet prohibited location. There’s currently legislation being written to punish these imposters with high fines, community service hours and even jail time.
Most people with legitimate needs and legitimate service dogs would much prefer to blend into the crowd then to always be questioned, watched and noticed. Although in many states it is not yet a crime, the legitimate service dog community eagerly awaits the day that all “service dogs” are legitimate, properly trained and helping their handlers in times of need.