Brachycephalic Syndrome

Summary

Brachycephalic syndrome, more correctly referred to as "brachycephalic airway obstruction syndrome" (BAOS), is the terminology applied to the diseased respiratory system that might show up in any brachycephalic dogs. This includes all bulldog breeds and any other breed whose "shortened" heads is considered a standard trait.

Though the respiratory compromise associated with brachycephalism is highly variable, any of those who inherit a shortened skull may suffer from it to some degree. It manifests as the obstruction of normal air flow through the respiratory tract.

The structures most notably affected include the fleshy soft palate, which is often overlong and may droop down to obstruct the opening of the larynx (elongated soft palate), the nostrils, which are often too small and narrow (stenotic nares), the larynx, where redundant folds prevent normal air movement (everted laryngeal saccules), and the trachea, which may be too small to accommodate the amounts of air required by these affected dogs (hypoplastic trachea).

Symptoms and Identification

Stertorous, noisy breathing is typical of affected animals. Snoring, snuffling, coughing, gagging, chronic raspiness, and reverse sneezing, too. Exercise intolerance and ready induction of cyanosis (visible as blue-tinged mucous membranes) are also common. Moderate to severe heat intolerance are typical and heat stroke, fainting or collapse is often the outcome should owners not abide by the pet's inherent respiratory limitations (such as when taking them out for a too-long walk or out on a hot day).

Gastrointestinal signs are fairly common for these pets, too. Dogs who gulp air in the process of attempting to breathe often eructate, gag, regurgitate and/or vomit frequently. Aspiration pneumonia is a not uncommon complication in these cases.

Diagnosis is achieved by observing the clinical signs. Directly visualizing the affected structures and assessing the degree of obstruction they provide is a necessary step towards determining whether the disease warrants definitive treatment.

Affected Breeds

Among dogs, the disease is typically most severe in the English Bulldog. Others include Pug, Boston Terrier, Pekingnese, French Bulldog, Cavalier King Charles Spaniel, Chinese Shar-Pei, Lhasa Apso and Shih Tzu.

Indeed, no brachycephalic breed is immune to this disease. Among cats, the Persian breed is most affected due to the extreme flattening of its facial features. Himalayans and Ragdolls are also afflicted.

Treatment

Treatment of brachycephalic syndrome is aimed at removing the airway obstruction where possible. In the case of hypoplastic tracheas, there is very little that can be definitively achieved. However, stenotic nares, elongated soft palates and everted laryngeal saccules can all be treated surgically.

Elongated soft palates and stenotic nares are very commonly resected to improve airflow across these structures. Although these are considered fairly simple surgical procedures, the risk of bleeding and aspiration and/or swelling and asphyxiation mean that these procedures are best left to board-certified veterinary surgeons or to veterinarians who perform a great many of these procedures every year.

Veterinary Cost

The cost of brachycephalic syndrome depends on the severity of the disease and the measures undertaken to relieve the obstructions within these animals' airways:

• Soft palate resection: $500 to $1,500

• Stenotic nares resection: $200 to $1,000

The cost of managing these patients can be impressive over the long term, even when medical and surgical concessions to improve the respiratory distress are offered.

Prevention

This is one disease for which prevention essentially requires that we discontinue breeding animals for their foreshortened faces and stumpy heads. Those severely affected should be removed from the breeding pool along with their first degree relatives. If these breeds are to humanely persist, every attempt should be made to breed for mild forms of the disease among brachycephalics.

References

Brayley, KA, Ettinger, SJ. 1995. Disorders of the trachea. In EJ Ettinger and EC Feldman(eds.) Texbook of Veterinary Internal Medicine, p. 754-766. W.B. Saunders Co., Toronto.

Hendricks, JC. 1995. Recognition and treatment of congenital respiratory tract defects in brachycephalics. In JD Bonagura and RW Kirk (eds.) Kirk's Current Veterinary Therapy XII Small Animal Practice.p. 892-894. W.B. Saunders Co., Toronto.

Canine Inherited Disorders Database