Grading reference
| Grade | Breathing sound | Exercise tolerance | Sleeping | What to do |
|---|---|---|---|---|
| Grade 0 Clinically unaffected | Silent at rest and after exercise | Exercises freely, recovers within a minute | Sleeps flat, no repositioning to breathe | No action needed. Suitable for breeding on respiratory grounds. |
| Grade 1 Mild — clinically unaffected | Faint noise audible only on close listening after exercise | Normal tolerance, recovers normally | Sleeps normally | No treatment needed. Monitor annually and keep the dog lean. |
| Grade 2 Moderate — clinically affected | Clearly audible noise at rest, louder after exertion | Stops on walks to recover; struggles in warm weather | Props head up or sleeps in unusual positions | Veterinary assessment recommended. Surgery often beneficial. Should not be bred without veterinary advice. |
| Grade 3 Severe — clinically affected | Loud, laboured breathing at rest; visible effort | Minimal tolerance; may collapse or cyanose | Cannot sleep flat; may wake to reposition and breathe | Urgent veterinary assessment. Surgery usually indicated. Must not be bred from. |
Weekly observation log
Record the grade you observe each day. Note the temperature too — signs that appear at Grade 1 on a cool morning frequently present at Grade 2 or 3 on a warm afternoon, and that pattern is exactly what your vet needs to know.
| Day | At rest | After a walk | Asleep | Temp (°C) | Notes |
|---|---|---|---|---|---|
| Monday | |||||
| Tuesday | |||||
| Wednesday | |||||
| Thursday | |||||
| Friday | |||||
| Saturday | |||||
| Sunday |
Red flags — contact a vet the same day
- Gums or tongue turning blue, grey or very pale
- Collapse, or inability to stand after exertion
- Breathing effort so pronounced the abdomen is visibly heaving
- Any breathing difficulty in warm weather — treat as suspected heat stroke
- Choking, gagging or an inability to settle at all
French Bulldogs UK · frenchbulldogs.co.uk/tools/boas-grading-chart/ · Aligned to the Kennel Club / University of Cambridge Respiratory Function Grading Scheme. Not a substitute for formal assessment by a trained assessor.
Why home observation matters
Owners consistently under-report breathing signs, for two reasons. The first is that the signs develop gradually, so they become the normal background of the household. The second is that a vet sees the dog for a few minutes, indoors, at rest, often on a cool day — which is precisely the condition under which a Grade 2 dog looks fine.
A week of dated observations, with temperatures noted, changes that conversation entirely. It is also useful evidence if you ever need to argue with an insurer about when signs began.
Use this chart freely
Print it, photocopy it, hand it out at a puppy class, put it on your practice noticeboard, share it in a breed group. No permission needed. If you publish it online we would appreciate a link back to this page, but it is not a condition of use.
Useful alongside this chart
In a suspected heat stroke episode, the number decides what happens next. Above roughly 40°C means cool immediately and drive. Guessing from how the dog looks is unreliable, and this costs less than a bag of treats.
Best for:Every household, kept where you can find it in a hurry
Check current pricePassive cooling with no power or freezer time. Useful for warm afternoons when the dog cannot be walked, though it is management rather than protection — it will not stop an episode already under way.
Best for:Summer months, and any dog with diagnosed BOAS
Check current priceA collar loads the throat of a dog whose airway is already restricted. A Y-front harness sits across the chest and leaves the trachea clear, which is the single cheapest intervention that meaningfully improves breathing on a walk.
Best for:Every French Bulldog, from the first walk onwards
Check current priceAs an Amazon Associate we earn from qualifying purchases.
Common questions
What is the Respiratory Function Grading Scheme?
A scheme run jointly by the Kennel Club and the University of Cambridge that objectively grades breathing function in brachycephalic breeds. A trained assessor listens to the dog before and after three minutes of trotting and assigns a grade from 0 to 3. Grade 0 and 1 dogs are clinically unaffected; Grade 2 and 3 dogs are affected, and Grade 3 dogs should not be bred from.
Can I grade my own French Bulldog with this chart?
Not formally. Only an assessor trained in the scheme can issue an official grade. This chart is for recording what you observe at home over a period of days, which is genuinely useful to take to a consultation — vets see your dog for ten minutes in an unfamiliar room, and that is not when the signs are most apparent.
Is snoring normal in French Bulldogs?
It is common, but it is not normal and it is not healthy. Audible breathing at rest indicates airway obstruction. A dog that snores loudly is a dog working hard to move air, and it warrants assessment rather than acceptance as a breed trait.
What grade should a breeding dog be?
Grade 0 or 1. The scheme advises that Grade 3 dogs should not be bred at all, and that Grade 2 dogs should only be bred under veterinary guidance and never to another affected dog. Ask any breeder for both parents' certificates.
How do I get my dog officially graded?
Through a veterinary practice with an assessor trained in the scheme. The Kennel Club maintains a list of participating assessors. The assessment takes around twenty minutes and produces a certificate valid for a defined period.
Related reading
This chart supports conversation with your vet. It is not a diagnostic tool and does not replace formal grading under the Respiratory Function Grading Scheme.