ELMONT, N.Y. -- Exogenous, the 3-year-old filly who suffered severe head trauma when she fell during the post parade of last Saturday's Breeders' Cup Distaff at Belmont Park, was euthanized early Friday morning after she was overcome by swelling of the brain.

	Exogenous won four of seven starts this year including the Grade 1 Gazelle Handicap and the Grade 1 Beldame.

At around 3 a.m. Tuesday, Exogenous lay down in her stall and was never able to get back up. She began to suffer seizures, according to Dr. Nancy Brennan, who treated the filly along with several other Belmont veterinarians.

"She had violent episodes of seizure activity and she was still unable to stand," Brennan said. "We decided in the best interests of the filly being down for more than 48 hours, this morning at 3:50, to euthanize her. The champion that she was, her desire to live was great just to survive the Saturday incident this long."

Brennan said the official diagnosis was head trauma with secondary hemorrhaging of the brain. Brennan said blood tests taken from Exogenous showed signs of an infection. Brennan said that Exogenous also was suffering from colic on Thursday night, which she passed around 9.p.m.

Exogenous was to be sent to New Bolton Center in Pennsylvania for a necropsy.

Exogenous, a daughter of Unbridled, won four of seven starts this year including the Grade 1 Gazelle Handicap and the Grade 1 Beldame - where she beat older horses - to put her in contention for a divisional championship. Exogenous finished second in the Alabama and Coaching Club American Oaks and third in the Mother Goose. For her career, Exogenous had a 5-4-1 record from 12 starts and earned $945,560 for owner and breeder Vernon Heath of Centaur Farms.

"I think she's a champion, naturally," said Randy Schulhofer, son of and assistant to trainer Scotty Schulhofer. "She danced a lot of dances, she showed up every time. She was getting better as she got a little older. The way [the Distaff] came out the other day, I think she's head of the class. It was a bad day for us and for racing. You hate to lose the stars."