Service dogs can be life-changing and lifesaving for humans

'A service dog can smell differences in our chemistry, when we're stressed or sick'

Originally Published: 13 MAY 21 05:06 ET Updated: 14 MAY 21 10:23 ET By Shauna Springer, CNN Editor's note: Shauna 'Doc' Springer is a leading experts on psychological trauma, suicide prevention and close relationships. She is the author of…