DALLAS -- The saying goes 'a dog is a man's best friend,' but photos posted on social media prove dogs are loyal to each other too.
Photos posted on Facebook show a Great Pyrenees standing guard over the body of his lifelong canine companion, a 1-year-old Shepherd mix named Marley.
Marley died after being hit by a car near the Dallas-Ft. Worth National Cemetery.
KDAF reports that the Great Pyrenees was spotted by a driver who took the photos, contacted animal activists and waited until help could arrive.
The photos soon went viral.
"He just sat there very stoic and looked off into the distance for quite a long time," said Teresa Cleek, manager of Dallas Animal Services, of the large dog.
Animal rescuers picked up the Great Pyrenees dog and began to look for his owners.
KXAS reports that Brian, the Pyrenees, and Marley had disappeared from the family home Sunday when someone left the garage door open.
The family was grateful for the support of rescuers.
The city of Dallas issued a news release saying the photos have created a wave of support "reminding people that dogs have the capability to love too."
CNN contributed to this report.