Jennifer Lopez's personal guard dog has been branded a "menace" for attacking a stewardess.

A report produced for a lawsuit against Jennifer and her husband Marc Anthony by flight attendant Lisa Wilson - who says she was attacked by the dog, Floyd, on a jet in 2006 - concluded that the animal "consistently endangered humans".

Dr. Karen Overall, a veterinarian with a Ph.D in zoology, produced the paper which claims the dog was a menace and its owners both knew it.

In the eight-page document, Karen wrote: "It is clear to me that Floyd, Mr. Anthony's personal protection dog, behaved inappropriately, aggressively and in a manner that consistently endangered humans."

The report was produced for the team representing Lisa, who claims the dog, a German Shepherd, headbutted her leg, causing her to fall and seriously injure her back.

Lawyer William Cafaro said: "The dog was obviously dangerous and we will prove at trial that it was only a matter of time before he hurt someone."

Joseph Varvaro, lawyer for Jennifer and Marc, responded in court papers saying he has hired his own animal behaviour expert to evaluate Floyd.