Finding a collar that fits a St. Bernard properly requires measuring the neck circumference and adding two inches for comfort — most adult males need collars in the 24- to 30-inch range. Flat buckle collars made from heavy-duty nylon webbing or thick leather are the standard choice for everyday identification and tag carrying. The hardware is as important as the strap itself: cast metal buckles and welded D-rings hold up far better than stamped or riveted hardware, which can deform or pull apart under the force generated when a 160-pound dog lunges unexpectedly. Martingale collars provide a controlled tightening action that prevents escape without the choking risk of a slip collar, making them an excellent option for St. Bernards whose thick necks and heavy fur can allow standard flat collars to slip over the head.
Harnesses are strongly recommended for St. Bernards, particularly during walks. A front-clip harness redirects pulling force toward the handler rather than allowing the dog to lean into its full body weight, which makes walks manageable even for owners who are significantly smaller than their dog. Back-clip harnesses are more comfortable for the dog but provide less pulling control and can actually encourage pulling behavior in a breed strong enough to tow a person off their feet. Dual-clip harnesses that offer both front and back attachment points provide the most versatility and allow the handler to switch configurations based on the walking situation.
Leashes for St. Bernards should be six feet long, made from heavy-duty nylon, biothane, or thick leather, and equipped with a sturdy swivel bolt snap rated for at least 200 pounds. Retractable leashes are a poor choice for giant breeds — the thin cord or tape cannot withstand the force of a sudden lunge, the braking mechanisms are unreliable at high loads, and the extended length removes the handler's ability to control the dog in close-proximity situations like passing other dogs or pedestrians. A standard six-foot leash with a padded handle provides the control and reliability that walking a giant breed demands.
For training purposes, a traffic lead — a short, 18- to 24-inch leash — can be useful for close-quarters control in busy environments, veterinary waiting rooms, or crowded outdoor events. Some owners attach a traffic handle directly to the harness for quick grabs when the dog needs immediate redirection. Whatever leash configuration is used, the connection points between leash, collar, and harness should be inspected regularly for wear, and any fraying, cracking, or hardware deformation should trigger immediate replacement.