Jonny Hilberath, the German team manager, said the condition of the rider has deteriorated, forcing him to pull out of the Games.
The withdrawal represents a severe setback for the country which is expecting a tough challenge in London from the likes of Great Britain and the Netherlands.
Germany have also been dealt a blow in showjumping, with Ludger Beerbaum forced to pull out.
His absence was felt at the Nations Cup in Aachen, where the Mannschaft finished in second place behind France, who unexpectedly got back on the victory trail.
The Germans suffered from a lack of consistency at the event and while Marcus Ehning with Plot Blue and Christian Ahlmann on Codex One fulfilled the terms of their contract by clearing on both rounds, Janne-Frederike Meyer with Cellagon Lambrasco and Marco Kutscher on Cornet Obolensky made an unusual number of mistakes, to the point that Kutscher ended up with a score of 32 points.