The Airedale is the largest of the terriers, developed in the mid-1800s in Yorkshire's Aire Valley from old black-and-tan terriers and the Otterhound. It hunted rats and otters, swam well, and later served as a messenger dog in World War I. Adults usually weigh 45 to 70 pounds and stand 22 to 24 inches, with a wiry black-and-tan coat, a bearded face and folded ears.
Many Airedales are clever, confident and playful, with a stubborn streak. They bond closely with their families but bore easily, so varied training and daily exercise matter. The coat sheds little but needs regular brushing and professional clipping or hand-stripping. In Philly, that means fitting a big, athletic dog into rowhouse stairs and busy sidewalks. A chase instinct toward squirrels and cats is common, though dogs vary.