COLLEGE STATION, Texas (AP) _ Veterinarians are hoping that Texas USA, the state's Sesquicentennial mascot bull, won't have to be put to sleep because of a broken back he suffered last week.

The 1,524-pound animal, which has a Texas-shaped mark on its forehead, was reported missing Wednesday on a ranch about 60 miles northwest of Fort Worth, where he had been kept. He was found on the ranch Saturday, injured and unable to walk.

The bull, with horns that measure more than five feet from tip to tip, was moved to the Texas A&M large animal clinic for treatment.

Dr. Jan Cornick, a veterinarian at the clinic, said the animal had fractured his back and was unable to walk because his hind legs were paralyzed.

''We're just keeping him on supportive therapy and making sure he is eating and drinking,'' she said.

The bull was to undergo X-rays on his back today that will determine whether he would have to be put to sleep, she said.

''He is a very much-loved animal, and we certainly won't jump to that unless it becomes our only alternative,'' Ms. Cornick said.

She said the bull, on loan from a Nebraska woman in honor of the Texas Sesquicentennial, may have fallen or been involved in a fight or may have been injured during breeding.

''He really isn't in any pain,'' Ms. Cornick said. ''He's very bright and alert. All his vital signs are normal - his heart rate and breathing rate. But it's just too early for us to tell.''

''He's a tough cookie,'' she said.