The 11-year-old was last seen at the Aintree Grand National meeting in April, finishing fourth behind stablemate L'Ami Serge.
Owned by JP McManus, he won two Grade One races, claiming the Fighting Fifth Hurdle and Christmas Hurdle in 2013, and won nine of his 25 starts under rules.
Henderson said in his Unibet blog: "It is with great sadness that I have to announce we have decided to retire dear old My Tent Or Yours.
"He has been a really special friend to all of us here at Seven Barrows, and Corky (Browne) absolutely adored him, but his old joints were starting to get a little bit rickety and when he's galloped around for so many years like he has, the wear and tear starts to show, so he deserves an honourable retirement.
"Luckily nobody retires horses better than JP and he can now join all his old friends like Binocular and the rest of the pensioners at Martinstown where he will be looked after like nothing else on earth - of which he deserves every bit of it."
"People have said he is the best horse never to have won a Unibet Champion Hurdle and I think they're right - he was second in three and second in a Supreme which must be a record itself to finish placed in four Grade Ones at consecutive Cheltenham Festivals.
"As well as that he won a Grade One Christmas Hurdle and a Grade One Fighting Fifth, but he really had his day in the sun when winning the Unibet International Hurdle last December.
"That was a fantastic performance and the appreciation he received from the crowd was quite remarkable and it was a day I'll never forget.
"If he'd had brakes he'd have been a fantastic chaser, you just couldn't do it with him because he was so strong, but he was a smashing fellow and was with us for seven years.
"Everybody loved him it now is the time to draw stumps. He had a good innings, retires in one piece, and I have no doubt he'll enjoy a long a happy future at Martinstown.
"Thank for all the great times, Tent, you'll be sadly missed."
Published 14:50 09/12/18