It never fails: while out on my rounds, the dog that I'm with brings a smile to the face of a passerby as we're making our way down the sidewalk. It’s almost a natural reaction.

Science has shown that a lot of other good things happen, too, when we are in the presence of a pet.

I’ve written about several therapy dogs that can be frequently be seen locally in schools, inpatient mental health facilities and in crisis intervention — and even nursing homes.

Trained therapy dogs are used to help kids in their reading, and in several settings, this is a common sight in and around Ann Arbor.

Horses are part of the routine for those that attend Therapeutic Riding, Inc.

I can certainly attest to the feeling that comes over me when my own pets, or those that I spend time with each day greet me: a joyful and relaxed energy just washes over me.

Animals really have a way of knocking down barriers, reducing stress and enabling us humans to open up in ways that might seem impossible otherwise.

So, imagine being called to responsibilities thousands of miles from home, away from loved ones, as members of our armed forces are right now. For many of them, it is their first deployment, and that can be especially rough.

Staff Sergeant Holly Torsch, who is from Howell, Michigan, is part of the 310th Expeditionary Sustainment Command stationed at the Joint Base Balad in Iraq. She understands that difficulty.

Torsch had an idea after seeing Sergeant First Class Zack — a 17-month-old Labrador/Golden Retriever mix, (yes, Zack is a ranking officer in the army), and his handler, Sergeant Brian Christman: invite them to come and boost the morale of the soldiers.

Christman, an occupational therapy assistant, and Zack, are members of the 98th Medical Combat Stress Control Detachment deployed from Joint Base Lewis-McChord, Wash.

The very act of interacting with a dog, especially one as playful and expressive as Zack, can make it easier for soldiers to open up and talk about any mental strain that they might be experiencing.

“We have a lot of people that are first-time deployed, so they are missing newborns, they are missing births; they are missing their family and their regular routine that they have,” said Torsch.

Many soldiers lose their reluctance to hang out a little longer and chat when Zack so naturally invites them to shower him with attention.

Really, who could say no to that?

“The combat stress classes, anger management, stress management, from tobacco cessation to warrior resiliency training —  basically what we do is provide soldiers with the tools through classes or prevention to help them get through their deployments, and help them get through the things they deal with here,” said Christman.

“I want people to understand that we are here for them, and we will work as hard as we need to, to do whatever they need.”

America’s VetDogs donated Zack to the army.

“It takes your mind off of being in a war zone and being in Iraq and away from your family, it kind of lets you play and relax a little bit,” said Torsch.

In the following video, you can listen to an interview with Torsch and Christman, and watch Zack work his puppy magic:

An error regarding the organizations to which America's VetDogs donates canines has been corrected.

Lorrie Shaw is lead pets blogger for AnnArbor.com and owner of Professional Pet Sitting. Shoot her an email, contact her at 734-904-7279 or follow her adventures on Twitter.