The photos were a rare attempt at a cutesy moment from a secretive agency better known for much darker stories. The number of C.I.A. personnel killed in Afghanistan now rivals the number of agency operatives who died in the wars in Vietnam and Laos decades ago. The agency has pushed for extended powers to carry out covert drone strikes in active war zones. So even the course load for its bomb dogs is high-stakes and rigorous.

“A few weeks into training, Lulu began to show signs that she wasn’t interested in detecting explosive odors,” read a statement on the C.I.A. website. “Usually it lasts for a day, maybe two.”

Because dogs can detect about 19,000 explosive scents, the C.I.A.’s prospective bomb sniffers face a six-week, seven-days-a-week training course in which they learn to identify threats. The dogs then undergo one-on-one training for 10 weeks with their handlers.

A successful graduate learns how to detect explosives in cars and luggage. The 60-hour canine workweek — part of a career that typically lasts seven or eight years — can include shifts with the United States Park Police, local police departments and the Drug Enforcement Administration.

On Thursday, the C.I.A. (barely) relaxed its typically tight-lipped stance to relay a few words about its infamous dropout. Lulu, the agency wrote, was a year and a half old, came to the C.I.A. from Susquehanna Service Dogs, was the smallest of six dogs in her class and was being trained for the Fairfax County Police Department in Virginia.