Nations-wide in the US and Canada there are regional battles going on about the definition of "medical service dog." In some places, a tiny terrier or chihuahua that has been trained to alert an owner of serious medical conditions such as Type 1 or Childhood Diabetes are being denied accesses that by law they're permitted, under the public's misbegotten belief that only large dogs for the blind, deaf, or wheelchair-bound could be "authentic" service dogs.

And as for dogs for "mere" mental health conditions, well, there's already a huge prejudice against the mentally ill, and people can be very close-minded about the idea of a service dog having special privileges due to its owner's bipolar condition, anxiety or depression. Not every mentally ill person is the most pleasant person to start with, so add to that a recurringly disdainful attitude toward tiny dogs and you've a recipe for shopowners breaking the law and feeling justified.

Now and then one can just about side with the bad guys on this one. A clothing store owner in the Wallingford neighborhood of Seattle was tired of a mentally ill non-customer being in her store repeatedly. She'd like to have kicked the woman out even if she hadn't had an untrained corgie that lifted his leg and pissed on the goods that must afterwards be discarded, and she believed her sign on the window "We reserve the right to refuse service" was within her rights as a shop owner.

Citing the sign in the window , she kicked the woman and her pee-dog out of the store. The crazy woman promptly sued, won a cash judgement, then showed up with her unbathed pissy corgie on a regular basis just to prove she could.

Charles Esler's service chihuahua Tita (photographed above and at left by Jake Pehls) is another example, though I blame Tita's evil behavior on Charles being such an effing nutter. Just look at that snarling human face in the photograph. I'd much rather deal with his nasty dog than him.

But as an example of Tita's unacceptable actions, she once became fixated on a woman in Dolores Park and began yapping at her mercilessly. As the woman fled, first at a saunter, then at a steady clip, then running like hell, Tita chased her right out of the park. Esler said it was somehow the fault of the woman.

That's one of many incidents involving a crazy man with his untrained so-called service dog who is supposed to help him be less crazy but doesn't seem to do so. Esler always has an "excuse" for why it was someone else's fault Tita lunged, chased, and frequently bit people, including the Chronicle reporter who'd tried his best to keep clear of the nasty beast and got bit anyway.

The issue here should be training. "I want my vicious little monster with me at all times because I'm crazy" isn't good enough. Real training should be a necessity to qualify as a service dog. A chihuahua is most certainly capable of learning therapy or service behaviors and take its job very, very seriously. They're smart and highly responsive to training.

But you don't give a random untrained German shepherd to a blind person and declare it welcome in restaurants though it hasn't a clue how to lead the blind. If a crazy person is reflected in the behavior of his or her dog, and he or she is unwilling to focus long enough for some serious obedience training in order to get a service dog liscense, then that liscense should indeed be withheld, and no special privileges conferred to the dog.

But at present there is only tension between those who disdain the mentally ill and the law that gives them easily abused privileges. When in a liberal place like San Francisco one discovers that even snakes, chickens, unruly pitbulls, pet rats and an iquana named Skippy, have all been declared therapy animals in the mood-stablizer category. So it's at least understandable that questions might arise.

And that doesn't count the outright frauds who have printed out a service animal badge from somewhere like Dogster.com, laminated it, and boldly pretended they had legal access to every public place.

Sadly in this "all or nothing" universe, where the mentally ill are despised with or without a dog, the Department of Justice in 2008 began formulating federal legislation to amend the Americans with Disabilities Act so that "animals whose sole function is to provide emotional support, therapeutic benefits, or promote emotional well-being, are not service animals." So far this hasn't succeeded, but that it's being attempted is horrifying.

For the Justice Department had the entire issue wrong. This should not be about the difficulty of assessing whether a "mental" condition is a fraud or not to get special privileges for a dog. Rather a dog should just be disqualified if it is noisy, nippy, or uncontrollable. It's too bad this rational middleground is not even being considered. It sometimes seems as though neither the crazy people who need them nor the "sane" people who would legislate against them have a lick of sense.