By Amy E. Feldman

PHILADELPHIA (CBS) - Emotional support sounds like something your girlfriend talks about. Guess what? So does the law.

Actress Kristin Chenowith got into a tussle with American Airlines recently when the airline gave her grief about bringing her dog onto the airplane. Ms. Chenowith brings her dog with her as he is a support animal and so she has a legal right to take him with her.

I don’t see her wearing any dark sunglasses or using a white cane. How could her dog be a support animal?

While Seeing Eye and other service dogs have long been exempted from regulations that prevent dogs in certain places, like restaurants and offices, people are now pushing the legal limits of the definition of “service” dogs. Restaurants, apartment houses, and other businesses may now be legally required to allow dogs who help not only those with physical disabilities, but also those who claim they require dogs for “emotional” support.

The Department of Transportation has stated that support animals must be allowed on planes – even animals who aid people with emotional problems like depression or anxiety. Every dog lover claims that their pet brings emotional support; while the definition of ‘support’ animal is still hazy, for the most part a doctor must have certified that a patient is keeping the pet for health reasons – but you can expect to see more dogs like Ms. Chenowith’s on airplanes, even if they aren’t flying American Airlines.