Harnesses, Collars and Leads: Fit Before Features

A flat collar is fine for carrying identification and for a dog that walks on a loose lead. It is a poor place to absorb repeated pulling: the neck contains the trachea, thyroid, major blood vessels and nerve supply, and pressure there has been associated with measurable effects including raised intraocular pressure, which matters greatly for breeds prone to glaucoma.

For any dog that pulls, that lunges, or that has an airway or spinal condition, a well-fitted harness moves the load to the chest where the dog can tolerate it. Flat-faced breeds, toy breeds prone to collapsing trachea, and dogs recovering from neck or back surgery are the clearest candidates.

Most poor harnesses fail in the same two ways: a strap running horizontally across the front of the shoulders, restricting the reach of the forelimb, or a girth strap sitting too far forward into the armpit, causing rubbing.

The front strap should sit below the point of the shoulder, not across it, leaving the shoulder blades free to rotate

You should fit two flat fingers under every strap, with no more slack than that

The girth strap should sit a hand's width behind the elbow, not against it

Watch the dog trot from the side: stride length should look unchanged with the harness on

Check fit monthly on a growing dog, and after any weight change

Check the skin under the straps weekly during the first month. Hair breakage, redness or a damp smell under the girth strap means rubbing has already started, and a different shape rather than a tighter fit is usually the answer.

A back clip is comfortable and suits dogs that already walk well but offers little steering. A front clip redirects a pulling dog towards you and is a useful management tool while loose-lead walking is trained, though a poorly fitted one can interfere with the shoulder. A harness with both, used with a double-ended lead, gives the most control with the least pressure.

For strong dogs, prioritise construction over gadgets: wide padded straps, metal rather than plastic hardware at load points, and stitching you can inspect. No harness is rated as a car restraint unless it has been crash-tested for that purpose; a walking harness is not a seatbelt.

Many dogs freeze, paw at the straps or refuse to walk the first time a harness goes on. Let the dog sniff it, feed treats as it goes over the head, and build up wearing time indoors before the first walk. A dog that learns the harness predicts good things will stand still to be dressed; one that has it wrestled on will start dodging.

If your dog already hates the current harness, changing the style often helps more than persevering — a step-in design avoids anything going over the head, which head-shy dogs find far more acceptable.

Choke chains, prong collars and electronic collars reduce pulling by making it unpleasant. They can appear to work quickly, which is why they persist, but they are associated with increased stress responses and risk of injury, they are restricted or banned in a number of jurisdictions, and they do nothing to teach the dog what to do instead.

Pulling is usually a reinforcement problem: pulling has always moved the dog forward. Changing that contingency — stopping when the lead tightens, rewarding position, using a long line in open spaces — addresses the cause.

A fixed lead of 1.8-2 m gives control with some freedom; retractable leads teach constant tension and cause injuries to hands and dogs when dropped. Cats walked outdoors need a purpose-made escape-resistant harness with a wide chest panel, introduced gradually indoors over weeks, and should never be attached to a collar.