Trainer King T. Leatherbury has been fined $400 by Maryland stewards and the state's horse identifier, James Rowan, was suspended for five days over the incident in which the horse Large As Life ran twice last summer at Pimlico as Dare To Command.

Both horses were trained by Leatherbury, the leading trainer in the country last year and a power in Maryland racing. The horses were owned by W. S. (Sandy) Sanders of Wilmington, Del.

The stewards, in a statement yesterday, said the improper identification of the two horses was the result of "human error" and "at no time was there any intent of fraud by anyone involved."

Large As Life, an unspectacular chestnut, finished out of the money twice (by 22 and 30 lengths) when bettors thought they were backing Dare To Command, a chestnut with $143,000 in earnings, The first time out, "Dare To Command' was 7 to 2; the second time 29 to 1.

Citing an investigation by William Ramsey of the Thoroughbred Racing Protective Bureau, the stewards said Large As Life raced as Dare To Command on May 27, 1978, and June 24, 1978.

"The true identity of the horse Large As Life was not discovered from the time he was apparently improperly identified while in Kentucky until such time as blood tests and other means of identification by the Jockey Club revealed that the real Dare To Command was in Florida on the dates he was supposed to be at Pimlico in 1978," the stewards' statement said.