Hi readers,
Feline chronic gingivostomatitis (FCGS) is one of the most devastating conditions in feline medicine. But while the clinical need is obvious, the commercial picture is anything but:
No approved drugs (yet);
No clean datasets;
Prevalence estimates that don’t really agree with each other.
So how do you size an opportunity like this without resorting to guesswork?
This week, we break down a structured epidemiological approach to modelling the FCGS market, and why understanding the assumptions matters more than landing on a single number.
What we’re watching
Sizing the FCGS commercial opportunity
Feline chronic gingivostomatitis remains one of the most treatment-resistant conditions in small animal medicine.
For companies developing novel therapeutics, that clinical frustration translates directly into commercial opportunity - but quantifying it is harder than it looks, and most attempts either underestimate the complexity or paper over it with false precision.
Standard market sizing tools typically not really effective in this situation:
There are no approved drugs generating auditable sales data;
Prevalence estimates vary by a factor of two or three across the published literature, reflecting genuine disagreement about diagnostic criteria as much as true epidemiological variation;
Diagnosis rates are poorly documented, treatment pathways are inconsistent, and the boundary between FCGS and other oral inflammatory conditions remains contested in clinical practice.
The result is that pipeline teams often lack even a defensible TAM range, nevermind the sensitivity analysis that serious investment decisions require.
A structured epidemiological approach doesn't eliminate that uncertainty, but it makes it legible and therefore useful.
Building the patient funnel
The core methodology is a sequential patient flow model: a series of filters applied to a base population, each representing a real-world constraint on the addressable market:
Total domestic cat population, filtered by vet-visiting rates, disease prevalence, clinical diagnosis rates, and the proportion of diagnosed cases that are realistic candidates for systemic therapy.
A UK example:
Approximately 11 million domestic cats, of whom 60–65% see a vet annually;
FCGS prevalence in the clinical population sits between 0.7% and 1.5% in the most-cited studies - a range reflecting genuine variation and diagnostic inconsistency. Applying a midpoint of 1.0% yields approximately 68,000 clinical cases.
Diagnosis rate then becomes the critical variable:
FCGS is frequently managed symptomatically in primary practice (e.g. extractions, corticosteroids, antibiotics) without a formal diagnosis. A rate of 60% is probably generous, producing a diagnosed population of roughly 40,000;
After excluding advanced cases, significant comorbidities, and owner compliance constraints, a treatable fraction of 35–45% is defensible, yielding 14,000–18,000 UK cats who might realistically receive a novel therapeutic.
At a treatment course price of £600–£1,200 - informed by existing biologic pricing in adjacent indications: the UK TAM falls in the range of £8–22 million across the scenario spread.
Why the assumptions matter more than the number
That range is wide, but a transparent model with explicitly stated assumptions is more valuable to a pipeline team than a precise-sounding figure built on opaque methodology, because it identifies where the uncertainty lives.
In this model, the dominant sensitivity is diagnosis rate: Move it from 50% to 75% and the TAM shifts by roughly 40%.
Prevalence is the second-order driver. Treatment uptake and pricing, counter-intuitively, matter less. Reasonable variation moves the output less than epidemiological uncertainty does.
That finding has direct commercial implications. Diagnosis rate improvement (through specialist referral networks, standardised diagnostic criteria, or veterinary education) is as important a commercial lever as drug pricing. Companies investing only in the latter while ignoring the former will leave a significant portion of their addressable market undiagnosed.
Cross-validation
A single-method model is always vulnerable to compounding errors. Standard practice is to cross-validate against independent approaches before treating any range as defensible:
The analogue market method: Canine atopic dermatitis (chronic, relapsing, historically undertreated) has generated billion-dollar markets following biologic approvals. FCGS is smaller and more heterogeneous, but the structural parallels are instructive. Scaling by relative indication size and cat-to-dog population ratios suggests a plausible global TAM of US$150–350 million, broadly consistent with the bottom-up funnel.
A top-down spend analysis provides a second cross-check. Global feline veterinary spending runs at approximately US$20 billion annually, with oral and dental disease accounting for an estimated 5–8%. Triangulating from that direction produces a range that overlaps with the patient funnel output - which increases confidence that the methodology isn't systematically off.
What this means in practice
Significant uncertainty remains, particularly around true diagnosis rates and treatment uptake in a market with no existing drug benchmark. Resolving it meaningfully requires primary data: structured interviews with feline medicine specialists and careful interrogation of the assumptions driving the model's most sensitive variables.
What epidemiological modelling provides is a rigorous framework for knowing which questions to ask - and what the commercial stakes of answering them correctly actually are.
Feline Business Brief provides competitive intelligence on the global cat sector. We analyse early signals, emerging risks and structural shifts across feline health, therapeutics, diagnostics and technology. Learn more here.
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