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Where our figures come from
Every monetary and prevalence figure on this site comes from one shared model, so the calculator, the cost pages and the health pages cannot disagree with each other. This page publishes the sourcing for all of it, including the parts that are still estimates.
Current status: 13 figures in the model remain modelled estimates rather than sourced values. They are listed at the bottom of this page, and labelled as estimates everywhere they appear. This count is generated from the model itself — it cannot be left out of date.
The distinction that matters most
Published research reports three different things that are easy to confuse, and confusing them is how a cost guide ends up overstating by a factor of three. Taking breathing problems as the example:
| What is measured | BOAS figure | Does it generate a bill? |
|---|---|---|
| Clinically affected on functional grading | 64–70% | No |
| Carries a recorded veterinary diagnosis | ~13% | Yes |
| Seen in one year of UK primary care | 5.5% | Yes |
A dog that is affected but never taken to a vet for it costs its owner nothing. So the calculator is driven by how often dogs are actually treated, not by how many are affected. The welfare figure is the more important number for the breed, and it is the one quoted on the health pages — but it does not belong in a cost projection.
Why we do not use the 4.5-year lifespan figure
You may have seen it reported that French Bulldogs live 4.5 years. That comes from Teng et al. 2022, which put life expectancy at age 0 at 4.53 years — the shortest of any breed in the study, against 11.23 years for all dogs. It is a real finding from real UK veterinary records.
The study's own authors caution that the breed's sample is "biased towards younger dogs", because Kennel Club registrations rose from 2,771 in 2011 to 39,266 in 2020. A population that grew that fast contains a great many young dogs, which inflates deaths at early ages.
So we project against the 9.8-year median from McMillan et al. 2024, which uses broader data less exposed to that artifact. Projecting a decade of costs off a number its own authors flag as demographically skewed would be wrong — but so would pretending the 4.53 figure does not exist.
The studies we rely on
O'Neill et al. 2021 — VetCompass
French Bulldogs differ to other dogs in the UK in propensity for many common disorders
UK primary-care records for 2,781 French Bulldogs against 21,850 other dogs. The source for disorder prevalence on this site.
McMillan et al. 2024 — Scientific Reports
Longevity of companion dog breeds: those at risk from early death
Median French Bulldog lifespan of 9.8 years, and a 40% increased risk of early death versus typical-faced breeds. This is the lifespan the calculator projects against.
Teng et al. 2022 — Scientific Reports
Life tables of annual life expectancy and mortality for companion dogs in the UK
Life expectancy at age 0 of 4.53 years — the shortest of any UK breed studied, against 11.23 for all dogs. Not used for projection, for the reason explained below.
PDSA — cost of owning a dog
Lifetime cost guidance for UK dog owners
Lifetime minimum of £5,000 for a small dog, rising to £12,200 by breed, size and lifespan. One of two anchors for running costs.
Condition figures, one by one
"Treated" is the lifetime probability of incurring the cost, and drives the calculator. "Affected" is the proportion of the breed with the condition, where that differs.
| Condition | Treated | Affected | Cost | Status |
|---|---|---|---|---|
| BOAS corrective surgery | 15% | 67% | £1,800–£4,500 | Sourced (cost estimated) |
| IVDD treatment or spinal surgery | 8% | — | £3,000–£9,000 | Estimate (cost estimated) |
| Recurrent skin fold dermatitis treatment | 20% | — | £200–£900 | Sourced (cost estimated) |
| Chronic allergy management | 13% | — | £400–£1,400 | Sourced (cost estimated) |
| Cherry eye / corneal ulcer treatment | 15% | — | £600–£1,800 | Sourced (cost estimated) |
| Caesarean section (breeding females only) | 80% | 1% | £1,500–£3,500 | Estimate (cost estimated) |
| Patellar luxation surgery | 6% | 2% | £1,500–£3,000 | Sourced (cost estimated) |
| Recurrent ear infections | 62% | 9% | £120–£800 | Sourced (cost estimated) |
Sources in full
BOAS corrective surgery
Derived: ~13% formally diagnosed (survey-based study, Germany 2025) and 5.5% one-year primary-care prevalence (O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence:); modelled slightly above diagnosis rate to allow for referral surgery not captured in primary care
Affected rate: Cross-sectional BOAS functional grading studies report 64-70% of French Bulldogs clinically affected (Grade 2-3)
Last verified
Recurrent skin fold dermatitis treatment
O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 2.2% for skin fold dermatitis, compounded over 9.8 years
Last verified
Chronic allergy management
O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 1.4% for atopic dermatitis, compounded over 9.8 years
Last verified
Cherry eye / corneal ulcer treatment
O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 1.6% for corneal ulceration, compounded over 9.8 years
Last verified
Patellar luxation surgery
O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 2.0% patellar luxation; modelled well below prevalence because low-grade cases are managed conservatively rather than operated on
Affected rate: O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 2.0% patellar luxation
Last verified
Recurrent ear infections
O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 9.4% for otitis externa, the most common specific disorder in the breed, compounded over 9.8 years
Affected rate: O'Neill et al. 2021, VetCompass, 'French Bulldogs differ to other dogs in the UK in propensity for many common disorders' (n=2,781 French Bulldogs), one-year period prevalence: 9.4% one-year prevalence for otitis externa
Last verified
Lifespan, running costs and premiums
| Figure | Value | Status |
|---|---|---|
| Life expectancy (median) | 9.8 years | Sourced |
| food, per year | £620 | Sourced |
| preventative vet, per year | £280 | Sourced |
| grooming and skin, per year | £180 | Sourced |
| equipment, per year | £120 | Sourced |
| licensing and misc, per year | £90 | Sourced |
| Premium at 8 weeks, per month | £45 | Sourced |
| Premium at 10 years, per month | £182 | Sourced |
| Puppy price, standard colour | £1,800–£3,000 | Estimate |
What is still an estimate, and why
13 figures are not sourced. Being specific about why is more useful than a blanket disclaimer:
- Treatment cost ranges. UK veterinary pricing is not published in any aggregated form. Verifying these properly means ringing practices and referral centres for current quotes across several regions — a phone-call job, not a research job.
- IVDD probability. The VetCompass study did not report intervertebral disc disease in the French Bulldog top-20, so there is no primary-care figure to anchor to. Left explicitly unsourced rather than attached to a citation that does not support it.
- Caesarean probability. The 1.3% dystocia figure is across the whole breed population, most of which is never bred from. Our 80% is conditional on breeding, which no published figure directly measures.
- Puppy prices and regional multipliers. Market observation. No authoritative index exists for either.
Corrections
If you can source one of the estimates above, or think one of the sourced figures is read wrongly, we would genuinely like to know — see the about page. Every figure carries a verification date, and anything older than a year should be treated with more caution than something checked recently.