Among many great qualities, a keen sense of smell helps make the dog an exceptional partner. Dogs are said to have ten to twenty times the number of receptors in their nose, compared to humans. This superior sense of smell makes them superior at certain tasks. Their athletic ability, strong bite, and agility make them superior at others. A dog is able to use all of their senses to detect people up to 1000 meters away. Partnered with a human handler, they can make a great team.

Some dogs are better at certain tasks than others. German shepherds, Dutch shepherds, and Belgian Malinois are the most common breeds you'll find. These breeds are smart, loyal, athletic, and can also be aggressive. For detection dogs, various retriever breeds are preferred.

Below are brief descriptions of just some of the roles that dogs can fill within military and police units.

Apprehension: Sometimes, apprehension dogs are in harms way by chasing down armed suspects. These dogs are trained to bite and hold dangerous suspects until they can be properly restrained.

Drug Detection: These dogs are trained to sniff out illegal narcotics. You will often see them in locations like airports, border crossings, and called to search vehicles suspected of hiding drugs.

Explosive detection: You will often see these K-9s in places where large crowds gather. These dogs can detect even trace amounts of explosive odors in the air.

Sentry: Sentry dogs are trained to warn of any strange people in the area. These dogs are often used for guarding vital installations. They can be especially valuable working in the dark, when visibility is low.

Patrol: Patrol dogs are trained similarly to sentry dogs, but there is one main difference. They are often trained to work in silence, to detect snipers and ambushes from enemy forces. Only dogs with both superior intelligence and a quiet disposition can be selected for this specialty.

Search and rescue: You will often see these dogs searching for missing or lost people. When a hiker goes missing in the woods, you will see these dogs in action. These dogs can also be trained to search for human remains.

Casualty: Casualty dogs are utilized to search for and report casualties in obscure areas. They are valuable when the time it takes to locate an injured person can mean life and death.

Arson: These dogs can also be known as accelerant detection dogs. Their job is to smell for traces of liquid accelerants that may have been used to start a fire. This information can be valuable in finding the source of a fire.