OCEANSIDE -- Stacy Steel, arrested Monday by federal authorities for allegedly obtaining controlled substances by fraud while working as executive director of the North County Humane Society, told investigators she got the drugs for her dog, according to the Drug Enforcement Administration.

Steel allegedly obtained 3,600 tablets of the prescription Vicodin over a five-month period -- from October 2005 to February 2006 -- special agent Dan Simmons of the Drug Enforcement Agency said Tuesday. As executive director, Steel allegedly directed others at the Humane Society to order the drugs, Simmons said.

Simmons said Steel is suspected of obtaining the 36 bottles of Vicodin pills by deceit, ostensibly for her dog.

The claim puzzles Jennifer Stewart, a veterinarian who served as interim director at the North County Humane Society between 2001 and 2003, and whose drug registration number was allegedly used without her knowledge to order some of the drugs.

"I can't imagine she would be using (Vicodin) for her dog," Stewart said, "and I don't know why she would be self-medicating her dog without the care of a licensed veterinarian."

The 38-year-old Steel will be arraigned on April 17 in San Diego Superior Court. The district attorney's office declined to comment on the case until after the arraignment.

Steel resigned from her $95,000 post as executive director of the Oceanside animal shelter March 25 in the midst of the DEA's two-month investigation.

Stewart said Vicodin, a prescription pain reliever, is not typically used in veterinary offices. A similar drug, Hycodan, is more commonly used by veterinarians as a cough suppressant, she said.

Vicodin might be used as a post-surgery pain reliever for animals, Stewart said. She said, however, that most veterinarians would simply write a prescription for Vicodin to be filled at a pharmacy.

Steel declined from outside her Encinitas home on Wednesday to answer any questions regarding her resignation, arrest or the drugs. She referred all questions to her attorney, Peter Liss.

"We plan on having this case heard in a court of law and nowhere else," Liss said Wednesday.

Stewart told the North County Times on Tuesday that the DEA asked her in February if she had given anyone at the Humane Society permission to order drugs using her drug registration number. The number is issued by the drug agency to doctors, veterinarians and others who dispense controlled substances, and is used to order controlled substances from drug distributors and manufacturers. Those drugs are then the legal responsibility of the veterinarian assigned that number.

Stewart said she told investigators that she had revoked permission for the Humane Society to use her registration number when she left the North County organization in 2003.

Stewart said she knows of at least one other veterinarian whose agency registration number was used without permission by the Humane Society. Neither the DEA nor the North County organization would confirm that assertion.

City News Service contributed to this story. Contact staff writer Philip K. Ireland at (760) 901-4043 or pireland@nctimes.com.