The Berwickshire handler made the decision after an MRI scan revealed the extent of the damage to the horse’s suspensory ligament, having been thoroughly examined by vets at Newmarket, scuppering hopes the 10-year-old might be able to resume his career next season.
“Basically, there is enough scar tissue in the suspensory ligament to feel it won’t stand hard training,” Thomson said.
“We’ve given it every chance to find out exactly what is going on and that is unfortunately the sad outcome, which we probably did expect.”
Seeyouatmidnight put Thomson’s Greenlaw stable on the map, right from winning his first start at 66-1 at Hexham in December 2013 to many highlights, including victories in the Rendlesham Hurdle at Haydock, the Dipper Chase at Cheltenham and beating Bristol De Mai in the Colin Parker Memorial Intermediate Chase at Carlisle.
Third in the Scottish National in 2016, his final race came in the Randox Health Grand National at Aintree in April, finishing 11th.
Thomson reflected on the impact Seeyouatmidnight has had on his career.
“He’s been an absolute star for us from when we started out,” he said of the gelding, who was bought to run in the colours of Patricia Thompson of Cheveley Park Stud before his Aintree bid.
“It was five years ago last week that he won at Hexham, beating Regal Encore. That went hand in hand with the start of our training success, because Seldom Inn won the bumper at Newcastle the next day. It just snowballed from there.”
He added: “He’ll stay with us. Hopefully he’ll be able to hunt and things. It’s not as though he’s just going to end his days in a field.
“He’ll still be fit enough to have another career. He’s just not going to stand the strain of getting him ready to race.”
Seeyouatmidnight won seven of his 17 starts and £141,000 in prize money.