BOAS review sharpens focus on grading, timing, and risk
Bottom line
A new review in Veterinary Clinics of North America: Small Animal Practice pulls together current thinking on brachycephalic obstructive airway syndrome, or BOAS, with a practical focus on grading disease severity, assessing patients more consistently, and matching treatment to risk. The authors, Kelley M. Thieman, Kathleen M. Ham, and Bryden J. Stanley, describe BOAS as a progressive airway disorder driven by primary anatomic changes such as stenotic nares, elongated soft palate, and everted laryngeal saccules, with secondary changes that can worsen over time, including laryngeal collapse. The review aligns with established guidance that functional assessment should go beyond a static exam, using history, respiratory auscultation, exercise tolerance testing, and, when needed, sedation or anesthesia for airway evaluation. It also reflects growing interest in more objective grading tools, including validated respiratory function grading schemes and newer remote or signal-based assessment methods. (pubmed.ncbi.nlm.nih.gov)
Why it matters: For veterinary professionals, the review reinforces that noisy breathing and exercise intolerance in flat-faced dogs shouldn't be dismissed as “normal for the breed.” Earlier recognition, weight management, heat and stress avoidance, and timely referral for surgical consultation can improve outcomes, especially before chronic secondary airway changes set in. That matters clinically because brachycephalic patients also face elevated anesthetic and postoperative risk, and recent outcome data show meaningful short-term complication rates after surgery, particularly in dogs with more advanced disease or emergency presentations. Emerging evidence also broadens the welfare picture beyond daytime stertor and stridor: brachycephaly has been linked to sleep-disordered breathing and inflammatory consequences, suggesting BOAS assessment may need to account for quality-of-life effects that routine exams can miss. (vet.cornell.edu)
What to watch: Expect more emphasis on standardized functional grading, earlier intervention, and practical tools that let primary care teams identify which brachycephalic dogs need referral before airway disease progresses. (pmc.ncbi.nlm.nih.gov)
Key facts
- Topic
- Brachycephalic obstructive airway syndrome (BOAS)
- Publication
- Veterinary Clinics of North America: Small Animal Practice
- Authors
- Kelley M. Thieman, Kathleen M. Ham, and Bryden J. Stanley
- Core focus
- Grading disease severity, assessing patients more consistently, and matching treatment to risk
- Primary anatomic changes
- Stenotic nares, elongated soft palate, and everted laryngeal saccules
- Secondary change
- Laryngeal collapse
- Assessment approach
- History, respiratory auscultation, exercise tolerance testing, and, when needed, sedation or anesthesia
- Objective tools
- Validated respiratory function grading schemes, plus remote or signal-based assessment methods
- Treatment message
- Earlier surgery tends to produce better outcomes than waiting for advanced secondary change
A newly indexed review on brachycephalic obstructive airway syndrome is putting a familiar problem back in focus for small animal practice: how to grade BOAS more consistently, recognize progression earlier, and choose treatment before chronic airway damage limits the benefit of surgery. Published in Veterinary Clinics of North America: Small Animal Practice, the article by Kelley M. Thieman, Kathleen M. Ham, and Bryden J. Stanley summarizes current approaches to classification, assessment, and intervention in brachycephalic dogs. (pubmed.ncbi.nlm.nih.gov)
That timing matters because BOAS is no longer viewed as a narrow surgical issue. Major referral and academic sources now frame it as a broader welfare and respiratory disease problem tied to breed conformation, progressive tissue change, peri-anesthetic risk, and quality-of-life impairment. The classic primary lesions remain familiar, including stenotic nares, elongated soft palate, and everted laryngeal saccules, but chronic obstruction can lead to additional pathology such as laryngeal collapse, pharyngeal changes, and lower airway consequences. Cornell notes that severity can increase with age, while UC Davis warns that signs like snoring, snorting, and loud breathing are still too often normalized by pet parents and clinicians alike. (acvs.org)
The review appears to emphasize functional grading rather than relying only on anatomy, which fits with the direction of the field. The respiratory function grading scheme developed through work at the University of Cambridge and used by groups including OFA evaluates dogs at rest and after exercise, helping distinguish clinically unaffected dogs from those with significant disease. More recent research suggests that remote grading by video and electronic stethoscope may be feasible, and Texas A&M has highlighted efforts to expand access to this kind of assessment through telehealth-style tools and shared databases. That could make BOAS triage more practical in general practice, breeding programs, and follow-up care. (bvajournals.onlinelibrary.wiley.com)
On treatment, the message from the broader literature is familiar but increasingly nuanced: conservative management still matters in mild cases, but earlier surgery tends to produce better outcomes than waiting for advanced secondary change. Standard surgical correction may include widening stenotic nares, shortening an elongated soft palate, and addressing everted saccules, while some centers are also discussing newer or adjunctive approaches such as laser-assisted techniques and expanded evaluation of upper airway anatomy. Cornell explicitly notes that earlier intervention leads to better outcomes, and ACVS guidance stresses that chronic cases with inflexible laryngeal cartilages may not get enough relief from routine upper airway procedures alone. (acvs.org)
The evidence base also underscores that BOAS surgery is beneficial, but not low stakes. A recent multi-institutional retrospective study of 413 dogs reported short-term major complications in 15.5% of cases and an overall mortality rate of 7%. Another review of newer outcomes research cited respiratory complications in 23.4% of dogs in one cohort, with mortality of 2.4%, and found higher risk in older dogs, emergency presentations, and dogs with secondary airway pathology. Separate summaries of risk factors have also linked worse perioperative outcomes to breeds such as French and English bulldogs, obesity, aspiration pneumonia, and physiologic instability at presentation. (pubmed.ncbi.nlm.nih.gov)
Expert commentary outside the review is pushing the field to think beyond daytime breathing noise. A new Journal of Veterinary Internal Medicine review on brachycephaly, sleep-disordered breathing, and inflammatory response argues that brachycephalic conformation is associated with obstructive breathing during both wakefulness and sleep, and discusses parallels with human obstructive sleep apnea, including inflammatory burden and broader physiologic effects. That doesn't change day-to-day BOAS workups overnight, but it does strengthen the case for treating sleep disruption, exercise intolerance, thermoregulation problems, and chronic respiratory effort as real welfare issues, not cosmetic breed traits. (academic.oup.com)
Why it matters: For veterinary teams, this review supports a more structured BOAS workflow: take noisy breathing seriously, document function before and after exertion, assess body condition, look for concurrent gastrointestinal or lower airway issues, and refer earlier when signs are progressing. It also reinforces the need for careful anesthetic planning and realistic counseling for pet parents about both the benefits and risks of intervention. In practice, the biggest shift may be cultural as much as clinical: moving BOAS from a condition that's often normalized in popular breeds to one that's actively graded, monitored, and managed like any other progressive airway disease. (vet.cornell.edu)
What to watch: The next developments are likely to center on wider adoption of standardized grading schemes, better objective screening tools for primary care and remote assessment, and more data on which patients benefit most from earlier surgery versus monitoring and medical management. (pmc.ncbi.nlm.nih.gov)