The Smooth Fox Terrier's compact neck and athletic build make collar and harness selection an important decision that affects both comfort and control. A flat buckle collar or a quick-release clip collar in a width of three-quarters to one inch is appropriate for everyday identification and leash walking in well-trained dogs. The collar should fit snugly enough that you can slide two fingers between the collar and your dog's neck but not so loose that the terrier could back out of it during a moment of excitement.
For dogs that pull on leash — a common trait in prey-driven terriers — a front-clip harness is a superior walking tool. The front attachment point redirects the dog's forward momentum toward the handler, naturally discouraging pulling without applying pressure to the throat. Back-clip harnesses are more comfortable for well-mannered walkers but actually encourage pulling in dogs that have not been trained to walk politely, so choose based on your terrier's current behavior rather than future aspirations.
Leash length and material matter more than many owners realize. A six-foot leash made from nylon webbing or biothane provides the ideal balance between freedom and control for urban and suburban walking. Leather leashes are comfortable in the hand and develop a pleasant patina over time but require more maintenance. Retractable leashes are generally not recommended for Smooth Fox Terriers because the constant tension encourages pulling and the thin cord can cause rope burns or snap under sudden lunging.
For terriers with a strong prey drive that may lunge after squirrels or rabbits during walks, a martingale collar provides a limited-slip function that tightens slightly under tension without choking. This style is particularly useful for Smooth Fox Terriers, whose heads and necks are similar in circumference, making it easy for them to slip out of standard flat collars during a sudden bolt.