“It was a bolt out of the blue,” Steph Croxford told H&H after finding out her former grand prix star Mr President has a serious heart murmur.

The 21-year-old was having a routine vet check on Monday (5 January) when it was discovered he had a grade five heart murmur — only one grade down from the most serious.

The charismatic gelding was officially retired from major competition at the National Dressage Championships in April 2013.

Since then Steph has still been riding him— and told H&H he was “feeling very well” — but now for safety reasons he has been permanently retired to the field.

“I’m sad and surprised, he had been going ridiculously well,” said Steph.

“He was feeling so good that we were considering popping him on the wagon alongside Mr Hyde [Steph’s top horse] and taking him to Myerscough to have some fun,” said Steph.

“He had really been lighting up and coming alive in training sessions, I could hardly hold him. It’s a shock, I can’t believe this has happened, you expect the wheels to come off first, like him going lame, but he’s fine in everything else.”

She added that the condition had come on very quickly, as Mr President last had his heart checked in September.

“It could correct itself, so I’ll have him checked in a couple of months, but he will now be living out in the field. The vet advised me not to ride him anymore, as he could go at any time and the last thing you want is to be trapped under a dead weight.

“He’s 21 and doesn’t owe us anything, and as I have two children I have to be sensible and can’t take that risk,” she said.

“Rimmer” as he is known, is now out in the field with his pal George for company.

“He’s a real mud monster, a complete hippo, and he thinks he’s in heaven at the moment,” she added. “I think it will hit him soon when he wants to come in and put his dressage diva shoes back on but he will adjust. He’s done everything for us and I just want him to have a happy retirement. I couldn’t contemplate putting him down, some horses with the condition live for several more years.”

Mr President has been a much-loved competitor over the years, with wins including the Saumur CDI grand prix freestyle in 2007.