The McNab Dog is bred for its working ability and is not recognized by the American Kennel Club (AKC). For this reason, the appearance of the McNab can vary considerably. The dog is medium sized with females standing 16-21 inches at the shoulder and weighing 30-50 pounds and males standing 18-25 inches at the shoulder and weighing 35-65 pounds. The dogs have a variety of ear sets from pricked ears to floppy ears and everything in between. Most McNabs are black or brown with white feet, white collars, white facial strips and white tipped tails, but tricolor McNabs are well known as well as mostly black McNabs. Some McNabs sport random white patches on their bodies and faces. Their eyes are set well apart, almond shaped, and brown, hazel, or copper colored with occasional marble flecked or powder blue eyes. The McNab coat is close, dense and weather resistant. They can have a slick single short coat, a short double coat, or a medium length single coat, but their fur is never long. One of the distinctive features of the McNab is their catlike feet which contribute to their agility.

The McNabs reputation as an indefatigable “all-weather” dog is also opening up a new avenue of work for the dog: Search and Rescue. Currently McNabs are working as evidence search dogs, cadaver dogs, archaeology dogs, and area search dogs for missing persons. Where many other breeds have to be pulled off the search because the dog is tiring, the only limitation for the McNab is the energy of its handler.