Grand National Meeting
- Venue: Aintree Racecourse
- Date: 4-6 April 2013
- First race: Thur 4 April 14:00
- Last race: Sat 6 April 17:40
- The Grand National: Sat 6 April 16:15
Coverage: Commentary on BBC Radio 5 live or 5 live sports extra (also available online and on mobile devices). Daily live text commentary on BBC Sport website
Irish Grand National winner Lion Na Bearnai is an injury doubt for the Grand National at Aintree on 6 April.
Trainer Tom Gibney said: "He's not fully fit and it hasn't been perfect. He's a very fit horse naturally, but I'd say now it's 50-50 for Aintree."
Albertas Run, The Package and Alfie Sherrin are among 16 horses withdrawn at the latest declaration stage.
Roi Du Mee, Midnight Chase, Calgary Bay and Planet Of Sound are others not now being considered for this year's race.
Recent Grand National winners
2012: Neptune Collonges
2010: Don't Push It
2009: Mon Mome
2008: Comply or Die
Lion Na Bearnai was a 33-1 winner by four-and-a-half lengths in the
Irish National at Fairyhouse last April
but has been beset by health problems since.
He has run only once subsequently - in the Hennessy at Newbury on 1 December - when he was unable to complete the race.
"He's good, he's still heading for Aintree just about, but things have not gone to plan and he's missed a lot of time," Gibney explained.
"He's done a couple of bits of work recently and is coming together, but whether we get there I don't know.
"We thought he was OK for the Hennessy but it turned out he wasn't so then he needed more time off.
"Then he had trouble with a hind leg, it gives him trouble once a year every year, it's a weak spot. That was before the Bobbyjo which was supposed to be his prep race and then there was a bit of ringworm in the yard. He's had everything bar the plague."
Irish trainer Colm Murphy decided against running
2011 Champion Chase winner Quito De La Roque
in the big race but is still likely to take the horse to Merseyside.
"The weights are going to go up and he would end up with nearly top-weight, so he'll probably run in the (Betfred) Bowl on the Thursday of Aintree instead," Murphy said.