Obstructive Airway Signs in Bernese Mountain Dogs: The Real Differential

The larynx sits at the top of the windpipe and works like a pair of doors. Muscles pull them open on every breath in and let them relax closed for swallowing and for voice. Those muscles are driven by a long nerve that runs down the neck and back up again, and in older large-breed dogs that nerve can gradually fail. When it does, the doors stop opening properly. Air has to squeeze past them, which produces the harsh inspiratory rasp, and because the same structures produce sound, the bark changes.

Heat is what turns a manageable narrowing into a crisis. A hot dog needs to move a great deal of air to cool itself, and it cannot. It pants harder, the tissues at the larynx swell from the effort and turbulence, the opening narrows further, and the dog panics. That cycle can escalate within minutes. A Bernese, already poorly equipped for heat because of a dense double coat and a 70 to 115 pound body, has less margin than most breeds before it starts.

The signs to know are a loud, harsh noise on the way in rather than on the way out, a hoarse or altered bark, gagging or coughing after drinking, exercise intolerance that has appeared over months, and in a crisis a dog with an extended neck, wide-open mouth, blue or grey gums and obvious panic. That last picture is an emergency at any hour.

Other causes exist and need excluding: a mass in the throat or chest, tracheal disease, or a foreign body. That is why the assessment involves examining the larynx directly under light sedation rather than reasoning from the noise alone.