Our 8 year old, 70 lb. female boxer is aggressive to non family members. Vet trips, clipping nails, etc. has become nearly impossible. Her vet said that in order to continue care, Maddy needs to be muzzled during visits. Is it possible to find a good fitting and comfortable muzzle for Maddy, that she will not be able to take off? We previously bought a Baskerville Muzzle and she quickly got it off.