If your student chooses to not dissect an animal and is given a hard time, explain to the teacher that you know the state policy. For example in Massachusetts the 2005 State Board of Education Policy gives anyone the right to refuse to cut up animals. In fact Massachusetts residents can mention the following policy:
“All public schools that offer dissection as a learning activity should, upon written request by a student’s parent or guardian, permit a student who chooses not to participate in dissection to demonstrate competency through an alternative method.” [2005 MA State Board of Education Policy]
Look up the policy where you live and have it ready to go to avoid being intimidated.