Corporal Jeff DeYoung was reunited with his black Labrador retriever named Cena on Thursday, June 5th, after being apart for four years. Cena had been DeYoung's bomb-sniffing dog and partner in Afghanistan in 2009.

According to the New York Daily News, Cena is a skilled canine that can sniff out 300 different kinds of explosives and 1000 different scents.

Talented dogs like Cena play an important role in the safety of our soldiers, both physically and mentally. Soldiers often build a special bond with their dogs, relying on them not just to find bombs and for physical protection, but also for comfort and companionship as in everyday life.

"My main goal was to protect him," DeYoung told ABC news. "I remember we would get into firefights and having to cover myself on top of him so he wouldn't get harm[ed]. It was all about him."

When DeYoung left the military in 2010, Cena stayed behind to continue serving the country. DeYoung went on to get married and start a family but throughout his life after service, he always had Cena in the back of his mind. After four long years, he went through Mission K9 Rescue to adopt his friend. The heroic canine had served six years in the military and had a hip problem that prevented continued service.

Canines that serve next to their soldiers find a special place, not only in their soldier's heart, but also with the hearts of the soldier's family.

Salvador and Sandra Diaz lost their son Staff Sgt. Christopher Diaz in September of 2011, but have recently been approved to adopt his Belgian malinois, Dino.

Initially, their request to adopt the dog was denied, because he was a young dog that could still work for the Marines. However, a special law allows grieving families in unique situations to adopt a working military dog. Under this law, Dino was allowed to become part of the Diaz family.

Salvador Diaz was the one who put in the request to adopt Dino and had planned on adding him to the family. While adopting Dino does not fill the void that Diaz's death has left in the lives of his family, it will provide a connection to him.

"We know that he's not going to replace Christopher but what he'll do is give us a little something that Christopher loved, and that was the Marine Corps and that was Dino," he told KGTV-TV.