What everyone is saying making sense, one way or another, but personally I am opposed to dissection of cats, I think at least the students should have a say as to whether they wish to participate in this procedure, for me I would be out of there smartly.

Whereas it might be ok for vet students to do this, I think there is a purpose there, but with students in a high school classroom, I fail to see how much they will benefit from doing this. Just MHO.