Respiratory Function Grading

 Brachycephalic Obstructive Airway Syndrome (BOAS) is a respiratory condition common in flat-faced breeds like French Bulldogs, resulting from anatomical features such as narrowed nostrils (stenotic nares), elongated soft palates, and tracheal narrowing. It causes breathing difficulties, exercise intolerance, heat sensitivity, and potential complications like regurgitation or collapse. While pet owners should monitor symptoms, RFG testing is primarily for evaluating breeding stock to reduce hereditary risks and promote healthier generations.

The YouTube video "BOAS: How to diagnose it" by Jane Ladlow includes several audio demonstrations of BOAS-related respiratory sounds, primarily in the latter half. Here's a timeline of the key sound examples based on the video content:

• 16:17: Demonstration of an "awake snorer" sound (low-pitched rumbling, often linked to soft palate or nasopharynx issues).
• 16:43: Example of stridor (high-pitched wheezing, typically laryngeal-related).
• 16:58: Another stridor sound bite (laryngeal focus).
• 17:05: Nasal stridor example (low-pitched grunting or snuffling from nasal obstruction).
• 18:20: Mild nasal noise in a one-year-old bulldog (pre-exercise, showing subtle obstruction).
• 18:28: Post-exercise recovery sound (no noise, for contrast with affected cases).

These clips are short (5-10 seconds each) and accompanied by Dr. Ladlow's explanations. For the full context, watch the video directly.

The RFG scheme was pioneered by the BOAS Research Group at the University of Cambridge, led by Dr. Jane Ladlow, a renowned veterinary surgeon specializing in brachycephalic health. Over two decades of research, starting in the early 2000s, Dr. Ladlow's work addressed the rising welfare concerns in breeds like French Bulldogs, Pugs, and Bulldogs. The scheme was developed to provide an objective, evidence-based assessment of BOAS severity, enabling breeders to make informed decisions and reduce the incidence of affected puppies.

Key milestones:

• Early Research (2000s): Dr. Ladlow's studies at Cambridge highlighted the need for standardized testing amid growing awareness of BOAS as a progressive disorder.
• Launch (2019): Partnered with The Kennel Club (UK), the scheme was introduced to improve breed health through functional grading.
• US Adoption (2023): The Orthopedic Foundation for Animals (OFA) implemented the RFG in the United States, adapting it for local breeders and expanding its global impact.
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This initiative stems from a commitment to welfare over aesthetics, countering indiscriminate breeding that exacerbates conformational issues.

 Photo Credit: Belinda Neil

The RFG is a non-invasive, standardized exam performed by certified veterinarians, lasting about 15-20 minutes. It's designed specifically for assessing breeding candidates (minimum age: 12 months; preliminary for younger dogs).

Steps:

1. Pre-Exercise Assessment: A health survey on breathing history, followed by a calm physical exam including auscultation (stethoscope listening) for baseline respiratory sounds and visual grading of nostril openness (0-3 scale).
2. Exercise Test: A brisk 3-minute walk (4-5 mph) to simulate mild activity, monitoring effort and noise.
3. Post-Exercise Evaluation: Immediate re-auscultation to assess recovery (should normalize within 5 minutes), checking for distress like cyanosis or excessive panting.

The test occurs in a controlled, calm environment to minimize stress. If severe signs are present pre-exercise, the test may be skipped for safety.

Grades are based on respiratory noise, inspiratory effort, and signs of distress, using a scale of 0-3:

• Grade 0: Clinically unaffected – no BOAS signs; ideal for breeding.
• Grade 1: Mild signs – unaffected clinically; suitable with caution.
• Grade 2: Moderate signs – clinically affected; breeding discouraged.
• Grade 3: Severe signs – clinically affected; exclude from breeding.

The highest category determines the final grade. Results help apply selective pressure to reduce BOAS incidence, though unaffected parents don't guarantee unaffected offspring.

BOAS: How to diagnose it" by Jane Ladlow from Cambridge Veterinary School) includes several clear sound bites demonstrating what BOAS (Brachycephalic Obstructive Airway Syndrome) sounds like in affected dogs. These audio examples are used to illustrate different types of respiratory noises associated with the condition, helping to differentiate the sources of obstruction.

• Awake Snoring: A low-pitched, rumbling noise typically caused by issues in the soft palate or nasopharynx. It sounds like a deep, vibrating snort or rattle during normal breathing, even when the dog is awake and relaxed. This is one of the most common indicators of mild to moderate BOAS.
• Stridor: A high-pitched, whistling or wheezing sound linked to laryngeal collapse (often seen in breeds like Pugs). It resembles a sharp, strained inhale or exhale, similar to a human with a blocked throat, and can become more pronounced during excitement or exercise.
• Nasal Stridor: Another low-pitched variant, stemming from nasal obstruction (e.g., stenotic nares or narrowed nostrils). This manifests as a grunting or snuffling noise, like labored sniffing through a congested nose, which may include gurgling elements.

These examples are played directly in the video as short clips (5-10 seconds each) captured from real dogs, with Dr. Ladlow explaining the underlying anatomy and how the sounds correlate to specific lesions. The audio is crisp and educational, making it a great resource for breeders or vets learning to identify BOAS symptoms. The video overall emphasizes the RFG scheme for grading these issues objectively.

 OFA-approved RFGS examiners are trained veterinarians who ensure reliable assessments. As of Spring 2024 (check OFA for updates), here's a directory by state (contact via email for appointments; they may host clinics or test at their facilities):