Brachycephalic Syndrome in Dogs
In-depth Information on Diagnosis
Diagnostic tests are needed in cases of upper respiratory obstruction, including: Complete medical history and physical examination The diagnosis of upper airway obstruction/brachycephalic syndrome is often simply made based on the breed of dog and the clinical signs. Although brachycephalic breeds of dog often make loud snorting noises while inhaling and are considered “normal,” clinical signs of weakness, cyanosis or fainting are indications that the dog is unable to get enough oxygen through his airways and may need treatment. Other concurrent causes for the dog’s clinical signs must be ruled-out to avoid missing the real problem. The veterinarian should obtain a complete medical history and perform a thorough physical examination. It is especially important that auscultation (examination with a stethoscope) of the chest is performed to listen for abnormalities in the lungs or irregularities in the heartbeat. Thoracic radiographs (chest X-rays) also may be taken, particularly if auscultation of the chest was questionable or abnormal, in order to confirm or refute heart or lung causes of the respiratory difficulty. Visual inspection of the nostrils confirms the diagnosis of stenotic nares. Stenotic nares have reduced openings compared with those of a normal dog’s nose. In order to confirm the presence of overlong soft palate and/or everted laryngeal saccules, the dog must be sedated or lightly anesthetized and the veterinarian must examine the back part of the oral cavity and larynx. An abnormally long soft palate will reach the base of the covering of the larynx and the epiglottis, and in severe cases it may be sucked into the laryngeal opening as the dog inhales. Normally the palate barely reaches the tip of this structure. Everted laryngeal saccules are seen arising from normally hidden crypts in the walls of the larynx adjacent to the vocal folds. They are not visible in a normal dog, but can be sucked out of their crypts with excessive negative pressure during inspiration (when air is drawn into the lungs). The presence of everted laryngeal saccules indicates a more severe form of brachycephalic syndrome and is thought to represent an early stage of laryngeal collapse.
In-Depth Information on Treatment
Treatment for upper respiratory obstruction may include one or more of the following: Many brachycephalic breeds of dogs have stenotic nares and overlong soft palates that cause stridulous breathing but never cause more serious clinical signs. These mild cases (“normal” for their breed) are usually managed conservatively without surgery. Conservative management is directed at preventing excessive respiratory effort requiring the dog to move air faster than the airways will allow. Obesity makes it more difficult for the dog to move air in and out of the lungs due to compression on the diaphragm and chest wall. Excess fat in the tissues around the airways impedes airflow through the airways. Obese dogs also have trouble eliminating excess heat and are forced to pant more than usual. These all cause the dog to have an increased respiratory effort and exacerbate the problem. Excessively stressful situations increase the tissues’ oxygen demands and will cause the dog to increase his respiratory effort. Hot, humid weather is very difficult for these dogs to deal with and they should be kept quiet in an air-conditioned environment whenever possible. A very important management technique, to prevent breathing becoming more difficult than it already is, is for these dogs to avoid the use of a neck collar. When the dog pulls of the collar it compresses part of the trachea, further exacerbating the airway obstruction. An over the shoulders-type harness should be used instead. Although mild cases are often managed conservatively, the risk for progression of severe airway disease exists. Months and years of increased inspiratory effort can lead to severe problems with the larynx. Close monitoring of the dog for worsening of clinical signs is imperative. The surgical corrections for stenotic nares and overlong soft palate are relatively easy and carry excellent prognoses when performed early in the course of the disease. Surgical management later in the course of the disorder is less successful and may not be possible if the larynx has become weakened.
Surgical corrections include: Stenotic nares resection is widening of the size of the opening through the nostrils by removal of a small piece of the wall of each nostril. It can be performed with a scalpel or a surgical laser. Resection of overlong soft palate is removal of the excess length of the soft palate that is hanging into the airway. It is carefully trimmed with a scalpel and scissors and then sutured closed, or a surgical laser can be used to minimize hemorrhage and requires no sutures. Resection of everted laryngeal saccules is removal of the swollen tissues protruding from the walls of the larynx at their bases. Occasionally, a tracheotomy tube is needed to allow an unobstructed view of the larynx to allow this procedure.