Champion trainer Paul Nicholls has revealed he is concerned about the health of some of his horses ahead of the Cheltenham Festival. 

Nicholls has cancelled a planned media day on Wednesday for the festival, which starts on 13 March.

"It is fairly obvious we had a moderate weekend. We have several horses coughing," Nicholls said.

Dual Cheltenham Gold Cup winner Kauto Star is not thought to be affected, said owner Clive Smith.

Somerset trainer Nicholls said: "It is my duty to leave no stone unturned now as we prepare for the last three weeks before the festival."

Hurdler Zarkandar, who earned a narrow success at Newbury, was the only winner from 31 Nicholls runners on Friday and Saturday.

Nicholls boasts a formidable squad for the festival and is seeking to make history on two fronts.

Big Buck's is being aimed at a fourth consecutive World Hurdle and 16th straight victory, while veteran Kauto Star looks to regain the Gold Cup having won in 2007 and 2009.

"I talked to Paul on Sunday night and everything is fine with Kauto Star as far as we know," said Smith.

"Obviously Paul's got an outbreak and one or two of his horses have got it, but hopefully it won't affect Kauto Star."