A rash of breakdowns at Philadelphia Park this year has officials looking for an explanation.Thirteen Thoroughbreds have been euthanized as the result of suffering racing or training injuries in the past two months, Craig Goldblatt, chief state veterinarian at the track, told The Philadelphia Inquirer Feb. 27."The number of breakdowns is up tremendously, and it's a real problem, a major concern," Goldblatt told the newspaper. "It's a problem, too, in that they're falling down. Five of the incidents resulted in spills and caused harm to several jockeys."The vet said he believed that the track surface was primarily responsible for the spills. "Other tracks have had the same weather but they've had fewer breakdowns."Roy Smith, track superintendent at the Bensalem track, said that was too simple."It's winter racing, you have a different racetrack every day," He told The Inquirer. "The temperature has been eight degrees below normal, and we've had some bad transitions due to extreme conditions," Smith said.Smith noted that bad weather also affects training patterns and suggested that many starters were not as fit as desired as a result.Ben Nolt Jr., executive secretary of the Pennsylvania Racing Commission, said officials in his department need three days of dry weather so they can peel back the track's surface and examine the foundation. An international track consultant is expected next week to inspect and make recommendations as well.