A child has been injured after being attacked by an emotional support dog on a Southwest Airlines flight in Phoenix.

The American airline announced yesterday that the dog's teeth 'scraped a child's forehead' when the young girl approached it on the flight to Portland, Oregon.

The girl, who is believed to be 6-years-old, is said to have screamed and cried, prompting paramedics to administer a health check before allowing the flight to take off.

Pictured, the dog who bit a little girl on a Southwest Airlines flight. This photo was taken by another passenger who believes dogs should not be allowed on planes

A Southwest spokesperson said the dog was in the plane's first row of seats with its owner, who said he had warned the girl not to approach the dog.

Police interviewed both the girl's family and the dog's owner, which resulted in the dog and its owner taking a later flight, Southwest said.

The incident is the latest in a long string of emotional-support animals not being allowed to fly on planes, an issue that has sprung debate on whether airlines should consider new restrictions.

Unlike service animals such as guide dogs, support animals need no training and tend to be used for mental health reasons rather than physical aliments.

Southwest - and most airlines - require passengers to provide a note from a doctor or mental health professional detailing why they need their animal with them to travel.

Southwest Airlines says a child was hurt by an emotional support dog aboard its flight traveling from Phoenix to Portland on Wednesday

Delta and United Airlines will soon require more paperwork and assurances from owners of support animals.

Both airlines said that they had seen a sharp rise in the number of support animals in the last year or so.

Last June, for example, a 70-pound dog flying on Delta as a support animal bit a passenger in the face severely enough that the man required hospital care.

Delta had planned to require owners of both service and support animals to submit health forms filled out by a veterinarian at least 48-hours before a flight.

But Delta softened the provision for service dogs after running into opposition from advocacy groups for the disabled who argued that the 48-hour requirement would make it impossible to catch last-minute or emergency flights.

Delta said it won't require customers to submit veterinarians' forms in advance for trained service animals but might 'in some cases' ask those customers to show their animal's vaccination records.

Fowl play: This is Dexter the peacock, whose owner, a Brooklyn artist, attempted to take him on board a United Airlines flight as an emotional support animal - but was denied

Earlier this month United followed similar suit requiring passengers to confirm that their animal is trained and has all its vaccinations, after a peacock named Dexter was not allowed aboard a flight from New York to Los Angeles.

Dexter's owner argued that she had a right to bring him on board as her emotional support animal.

The airline, in turn, said that it had witnessed a 75 per cent year-over-year increase in customers bringing emotional support animals on board, which was leading to a significant increase in on board incidents involving animals.

MailOnline reported how airlines are convinced that some emotional support animals are abusing the rules - especially when most passengers often have to pay $125 (£90) or more each way to bring a small pet on board.

None of the new rules for support animals would apply to pets small enough to fit in carriers that go under airplane seats.

There is no charge for service and support animals.

Southwest said they had started reviewing its support animal policy before the event, which happened on Wednesday.

