 The biophilia hypothesis suggests that if we see animals at rest or in a peaceful state, this may signal to us safety, security and feelings of well-being which in turn may trigger a state where personal change and healing are possible.Six neurotransmitters that influence mood have been documented to release after a 15-minute or more interaction with animals.Mirror neuron activity and disease-perception through olfactory (smelling) ability in dogs may also play important roles in helping dogs connect with humans during therapeutic encounters.