Sgt. Korbein Schultz had initially pleaded not guilty to charges including conspiring to obtain and disclose military defense information and bribery.
Retired Adm. Robert Burke was indicted last month.
VA would see a 10% boost in funding under a plan advanced by Republican appropriators on Tuesday, but Democrats oppose other parts of the bill.
The Department of Veterans Affairs is slated to largely end testing on dogs, cats and nonhuman primates within the next two years.
