We already knew dogs did double duty as friends and heroes, but it's always nice to get a reminder.

Purina's Better With Pets Summit on Tuesday featured an exhibit from America's VetDogs focusing on the service canines assigned to assist American veterans.

VetDogs provides trained service animals for veterans with low hearing and deafness, low vision and blindness, physical disabilities and post-traumatic stress disorder (PTSD). The organization also provides dogs for use in military hospitals and VA recovery programs.

At the summit, several service dogs demonstrated a few of their helpful skills, including nightmare interruption — a procedure in which the service dog pulls bed covers off the sleeping veteran if it detects that he or she is having a nightmare.

A service dog from America's VetDogs demonstrates nightmare interruption at Purina's Better With Pets Summit on November 3, 2015.

A service dog from America's VetDogs demonstrates nightmare interruption at Purina's Better with Pets Summit on November 3, 2015.

Dogs are also trained in item retrieval.

A service dog from America's VetDogs demonstrates item retrieval at Purina's Better With Pets Summit on November 3, 2015.

U.S. Army veteran Kent Phyfe, who served in the military for 15 years, received his service dog, Mike, after a recommendation from his VA doctors. Mike assists with, among other tasks, nightmare interruption and pushing buttons — including a 911 button in times of emergency.

Phyfe also has neurocardiogenic syncope, a condition that can cause him to faint without warning. Mike is trained to activate a loud, high-pitched alarm should Phyfe pass out.

"He is such a large dog — his bark is so loud that it's not a good thing. It might scare people off," Phyfe said in a VetDogs video. "So he pulls an alert."

VetDogs reps were pleased with the reaction to Tuesday's Better With Pets demonstrations. "I believe everyone who stopped by the VetDogs service dogs demonstrations left with a greater understanding of the work that goes into training service dogs, the variety of tasks these dogs are trained to do to mitigate veterans' disabilities and the strong bond between veteran and dog," communications manager Bill Krol told Mashable.

"We were very excited to demonstrate how amazing service dogs are," he said.