The Associated Press reports that the dogs and their handlers, provided by a private Dutch foundation that regularly assists police, will be on the Caribbean island through the end of this week.
The cadaver dogs worked for several hours Tuesday, according to AP, but the search, which focused on the southeastern section of the island, turned up empty.
Cadaver dogs are generally used in place of standard search and rescue dogs when a dead body is the expected outcome of a search.
Gardner, of Frederick, was reported missing Aug. 2 by Gary Giordano, of Gaithersburg, with whom she had been traveling. Giordano told police that Gardner was swept out to sea and drowned while the two were snorkeling off the southern tip of the island.
Giordano was jailed shortly after reporting Gardner missing and remains the only suspect in her presumed death.