By: Paul M. Manino, DVM, DACVIM, Gulf Coast Veterinary Specialists, www.mygcvs.com
It is 5:30 and you have just arrived home from a long day at work to be greeted by your beloved family pet Sadie. A Yorkshire terrier, Sadie becomes so excited at your arrival that she begins coughing. Having seen this before and knowing it will resolve quickly, you greet her warmly and go about trying to help your spouse prepare dinner. You quickly realize, however, that this time is different. For some reason Sadie’s coughing is lasting longer than usual. When you go to check on her you find her struggling to catch her breath as if she had something stuck in her throat. You decide to sit with her for a few minutes and fortunately she eventually calms down and her coughing resolves. Driven out of concern for her well-being though, the next morning you bring Sadie in to be evaluated by your family veterinarian. During her examination, you notice that Sadie begins coughing again when pressure is applied to the underside of her neck. Your veterinarian informs you that she is concerned Sadie may have a problem with her trachea and requests taking radiographs of her chest and neck. You agree with her recommendations and wait anxiously as they take Sadie into the back to obtain her images. A few minutes later your veterinarian returns and informs you that her suspicion was correct, Sadie has a collapsing trachea.
The trachea or “windpipe” is normally a somewhat rigid tube that connects the nose, mouth, and throat to the lungs. Its rigidity is provided for by a series of C-shaped cartilage rings very much like the cartilage that shapes each of our noses. As these rings weaken they restrict the amount of air that can flow into the lungs, ultimately leading to the signs we see clinically. In some cases the entire length of the trachea may be affected whereas in others the weakening is confined to that portion contained either inside or outside the chest cavity.
Tracheal collapse is one of the most common causes of coughing in small and toy breed dogs. It is a progressive disorder that most often afflicts middle-aged dogs with Poodles, Yorkshire terriers, and Pomeranians most commonly affected. Clinical signs can range in severity from a very mild, intermittent “honking” type of cough to severe respiratory distress and collapse. Occasionally, vomiting, gagging, and retching may also been witnessed. The coughing is often exacerbated by excitement and usually will abate when the animal is calmed or sedated. Other risk factors for the development of signs include obesity, repeated pulling on a neck collar, exposure to inhaled irritants (ie. cigarette smoke) or high environmental temperatures, heart disease, respiratory infection, or a recent anesthetic event as might occur with a dental cleaning.
The diagnosis of tracheal collapse can usually be made via a thorough history, physical examination, and radiographs of either the chest or neck. Occasionally, however, additional testing such as fluoroscopy or bronchoscopy is needed. Fluoroscopy involves the use of a special x-ray machine that can view the airways in real-time whereas as standard radiograph can only evaluate a single, still image. On the other hand, bronchoscopy involves passing a special camera down into the airways to monitor their behavior as the patient breathes. Both of these procedures require special equipment and training and can usually only be performed in a specialty hospital.
Though there is no cure for tracheal collapse many dogs can do well with treatment and a few lifestyle changes. Maintaining an ideal weight, limiting exposure to inhaled allergens or high temperatures, and avoiding neck leashes can decrease the frequency with which some dogs manifest symptoms. In most cases, however, specific medical therapy is usually required. Such therapy may entail the use cough suppressants, sedatives, antihistamines, antibiotics, steroids, and/or medications to help open the airways themselves (bronchodilators). In extreme cases, surgical placement of special prosthetic rings or a metallic stent can be considered. Such procedures, however, are considered strictly salvage procedures and are not intended to replace aggressive medical therapy.
Tracheal collapse can be a devastating and life-limiting disease in some dogs. Any dog that exhibits signs of unrelenting coughing, labored breathing, collapse, or discolored gums should be evaluated by a veterinarian immediately. Though in most cases complete resolution of all clinical signs is not possible, many dogs can enjoy a good quality of life with proper care and the observation of a few precautions.