Not sure how enforced these are but here is the VA code governing students. Your correct not very specific, but if you call the board they are very nice and can give you details.
18VAC150-20-130. Requirements for practical training in a preceptorship.
A. The practical training and employment of qualified students of veterinary medicine or veterinary technology shall be governed and controlled as follows:
1. No student shall be qualified to receive practical training unless such student shall be duly enrolled and in good standing in a veterinary college or school or veterinary technology program accredited or approved by the AVMA and in the final year of his training or after completion of an equivalent number of hours as approved by the board. The student shall be engaged in a preceptorship as defined by the board and authorized by his college or school.
2. A veterinary preceptee may perform duties that constitute the practice of veterinary medicine under the on-premises supervision of a licensed veterinarian.
3. A veterinary technician preceptee may perform duties that constitute the practice of veterinary technology under the on-premises supervision of a licensed veterinarian or licensed veterinary technician.
B. Prior to allowing a preceptee in veterinary medicine to perform surgery on a patient unassisted by a licensed veterinarian, a licensed veterinarian shall receive written approval from the client.
http://www.dhp.virginia.gov/vet/leg/Vet%20Med%2011-29-07.doc