Dog Training- 2 People Team. What Is The Assistant Called?

I'm writing fiction. One person needs to hold the dog until he is called by his trainer. What is the correct name of that second person? A ...

Trying To Raise Money For An Assistant Dog Training Facility/rescue Organization.any Ideas.?

My father currently trains assistant dogs for the physically disabled out of his home for free. We are in desperate need of a facility- so I am looking for ideas ...