“As is required by the U.S. Department of Agriculture to progress from conditional licensure to full licensure, Aratana has initiated the extended field study for its Canine Osteosarcoma Vaccine, Live Listeria Vector (AT-014) at approximately two dozen veterinary oncology practice groups across the United States and study sites have started enrolling dogs.”
So... A field study was required to gain conditional approval and a further field study is now required to move from a conditional license with 24 sites to full licensure. Requiring an indeterminate number of field studies is obviously the USDA’s way of slow walking full approval so they can delay making a decision or taking a position for as long as possible. Bureaucrats doing what bureaucrats do best.