By Christie Long
Last week I was getting ready to anesthetize a really nice little dog for what I thought would be a routine dental cleaning. My technicians were placing an intravenous catheter in the dog’s front leg and I was several feet away, working with another patient when they called out to me to come listen to the noise my dental patient was making.
I got there just in time to hear a sound that can only be described as a cross between a “hack" and a “honk". Shortly thereafter her gums and tongue turned a troubling shade of purple, which indicates a low oxygen state. We began providing her with supplemental oxygen, which she gratefully accepted, and rewarded us by quickly returning to a healthy shade of pink.
I called my patient’s owner and suggested that we postpone the dental cleaning in favor of perhaps learning why this dog experienced a sudden respiratory crisis.
X-rays of her lungs showed a very obvious and very severe narrowing of her trachea, starting at the point where the trachea leaves the neck and enters the chest. This is a condition known as tracheal collapse, and it turns out it’s a problem a lot of dogs have, especially little ones. Owners often report that their dogs cough or gag when pressure is applied to the neck, like when the dog pulls at the leash.
Most of us can appreciate that the trachea is a long tube, and its function is to carry air that is breathed in from the outside of the body into the lungs. The trachea contains rings made of cartilage; their purpose is to hold the hollow tube open so that air can pass through it unimpeded. When the cartilage is weak, the tube flattens and does a poor job of conducting air, usually temporarily. This is tracheal collapse, and it can happen anywhere along the trachea, but most commonly it occurs where I saw it in my patient.
Dogs with tracheal collapse are born with this weakened cartilage, but the problems associated with it are usually not apparent until later in life. Things that can complicate tracheal collapse include obesity, general anesthesia involving placement of a tracheal tube, respiratory infections, inhaled irritants, and heart enlargement. Often correcting the complicating factor can greatly improve the symptoms.
In the case of my patient she has already started a weight loss program. For some patients medications such as cough suppressants or broncho-dilators may be necessary.
When tracheal collapse is severe, patients can suffer a serious respiratory crisis requiring emergency treatment. Surgery may even be necessary to place a rigid tube into the interior of the trachea to prevent collapse.
It has been suggested that dogs with collapsing trachea have liver disease at an alarmingly high rate, likely thought to be brought on by a constant low-oxygen state. Because of this, it is recommended that dogs with tracheal collapse undergo liver function tests.
Christie Long is a veterinarian at the VCA Animal Hospital in Fort Collins, CO. Long left her job in software sales in 2000 to travel for 13 months. Along the way, she was touched by the plight of the animals she saw and somewhere in the Nepalese Himalayas she vowed to return to school to become a veterinarian. While she often finds end-of-life situations heart-wrenching, she considers herself blessed to be called upon as a trusted adviser to families during difficult times. Dr. Long’s family includes her husband and travel partner, Wiley, their 5-year-old son, Wiley IV, their dogs Pancake and Gizmo and cats Sneaky and Sidh.