Sadly no. We get many requests of this nature, particularly at the beginning of a new school term.
Unfortunately, due to insurance restrictions, we are unable to permit volunteers to use their dog in the course of their employment. You would therefore not be able to use your own dog during the course of your teaching/sessions.
As a volunteer your primary responsibility is to that of your dog and you are unable to do this if you are running a class or therapy session. If there was an emergency and the school had to be evacuated, as a volunteer you would be responsible for the dog but as a teacher you are responsible for the children and therefore the welfare of either would be compromised.