In this April 1, 2017, file photo, a service dog named Orlando rests on the foot of its trainer, John Reddan, of Warwick, N.Y., while sitting inside a plane at Newark Liberty International Airport.

The public has some strong opinions about the surge in emotional support animals on board airplanes.

The U.S. Department of Transportation has received about 950 comments about the increase in emotional and psychiatric support animals in airplane cabins since it put out its request for public comment five days ago.

The agency is considering changing its rules for bringing such animals on board. These animals can fly free of charge and without a carrier under the 1986 Air Carrier Access Act.

But airlines, including Delta, United and American this year have tightened restrictions on such support animals, asking passengers to provide signed documents that state the animal can behave, after passengers and crew complained about allergies and soiled cabins, and raised concerns about travelers getting certification fraudulently. A passenger last year was mauled on a Delta flight by a passenger's emotional support dog.

The DOT last week said it would not punish airlines for issuing "reasonable" restrictions on the movements of such animals around the cabin.

"What about passengers who suffer from allergies to animals on board flights? Will airlines be providing separate flights for those passengers? Or, will there be designated flights for those who must travel with their service animals?" asked commenter Shirley K.

Richard Deal urged regulators to only permit service animals for the blind.

"If flying does not work for you then drive or walk. Enough is enough," Deal said.