But once home and placed with an adoptive family, medical bills are sure to stack up. Many of these retired dogs are more than 9 years old and are plagued with battlefield issues such as arthritis and even post-traumatic stress disorder. The Defense Department, Kandoll says, should allow military veterinarians to treat retired dogs.

A dog's medical history is made clear during the adoption process, according to the Defense Department.

"So they go into it eyes wide open," Proctor said. "If you buy that truck, how far do you want the American taxpayer to be on the hook for the truck's oil changes and tuneups for its life?"

A one-month supply of all the medication the dog needs is also given to the adopter to ensure that the adoptive family has enough time to procure veterinary care for the animal, according to Proctor.

The brave dog Lex that stayed by his handler's side until the end is now 11 years old. He is doing well but has PTSD and pieces of shrapnel that cause spinal complications, Rachel Lee said.

"To be able to reclassify them would be to also get them help in a better manner," Lee said. "To be able to have them looked at differently -- as a vet, as a soldier and to give them benefits."