FrenchBulldogs.co.uk
1 The trial
Set up once. Everything stays on this device, in this browser. Clearing the browser's site data clears the diary, so save a backup now and then.
The trial
2 Today
3 The chart
4 The challenge
5 The card for the vet
How the trial works
A food allergy cannot be found by a blood test. The only reliable test is to feed a diet the dog cannot be allergic to, for long enough, and see. "Long enough" has a number: in the review of published trials, more than 80% of food-allergic dogs were better by week 5 and more than 90% by week 8, so the guidance is eight weeks at least. The international guideline on canine atopic dermatitis puts it in one sentence: an eight-week restriction-provocation dietary trial should permit the diagnosis of food allergy in most dogs.
"Restriction-provocation" is the whole method. Restriction is the eight weeks on the diet and nothing else. Provocation is the challenge: if the dog is better, the old food goes back in and you watch for a flare. More than 90% of food-allergic dogs flare within 14 days. Better on the diet alone proves less than people think, because skin often improves for other reasons over two months; better, then worse on the old food, then better again, is the evidence.
What the log does
It records the itch score every day on the scale vets use, plus the four things that matter in this breed and get missed on a scratching-only diary: ears, skin and folds, paws and stool. It counts every day something else was eaten, because those days are the ones the vet needs to know about. It draws the chart with the scale's normal range shaded, marks the week-5 and week-8 milestones with their figures, runs the challenge counter, and prints a one-page card.
It also says "ring the vet" on four patterns: three days at eight or more, two days of red ears, two days of a sore fold, three days of diarrhoea. Those are our thresholds, not clinical ones, and the page says so each time. They are there because a trial diary can turn a bad week into "wait and see" when it should not.
The scale
Read it from the bottom up, and pick the first description that is not true. That is the instruction the labs give with it, and it is why it works better than "how itchy, one to ten".
| Score | Means |
|---|---|
| 10 Extreme | Itching constantly, whatever is happening. Has to be physically stopped. |
| 8 Severe | Long bouts of itching, at night, and possibly while eating, playing or out. |
| 6 Moderate | Regular itching. May itch overnight, but not while eating, playing or out. |
| 4 Mild | More frequent itching, but not when sleeping, eating, playing or out on a walk. |
| 2 Very mild | Occasional itching, a little more than before the skin problem started. |
| 0 Normal dog | Itching is not a problem. The odd scratch, as any dog does. |
Adapted from the owner-assessed pruritus scale of Hill, Lau and Rybníček (2007), validated by Rybníček and colleagues (2009), as reproduced in a UK dermatology laboratory's diet-trial instructions. Normal range 0 to 1.9.
Where the numbers come from
Every figure the tool shows, and whether it is verified against a named source. Quotes and links are on where our figures come from. UK charities give 6 to 12 weeks for a trial; the tool uses eight, from the reviews.
| Figure | Value | Status |
|---|---|---|
| Itch scale anchors (adapted from Hill/Rybníček) | Normal dog, Very mild, Mild, Moderate, Severe, Extreme | Adapted reproduction; original paywalled |
| Normal range on the scale, 0–1.9 | 0, 1.9 | Verified, 2026-09-11 |
| Better by week 5: more than 80% | week 5; fraction 0.8 | Verified, 2026-09-11 |
| Better by week 8: more than 90% | week 8; fraction 0.9 | Verified, 2026-09-11 |
| ICADA on the 8-week trial | An 8-week restriction-provocation dietary trial should permit the diagnosis of food all… | Verified, 2026-09-11 |
| Challenge window, 14 days | 14 | Verified, 2026-09-11 |
| Common food allergens | beef, dairy, chicken, wheat | Verified, 2026-09-11 |
| Prevalence of food allergy | allDogs 0.01–0.02; itchyDogs 0.09–0.4 | Verified, 2026-09-11 |
| Year-round flea control (ICADA) | Dogs with AD should be treated year-round with an effective flea control regimen. | Verified, 2026-09-11 |
| Infections cause flares (ICADA) | Bacterial and yeast skin and ear infections are common causes of flares in dogs with AD. | Verified, 2026-09-11 |
| The "nothing else" list | Treats stopped, all of them, Chews, dental sticks, bones and pig ears stopped, Table food and scraps stopped, and everyone in the house told, Flavoured medicines checked with the vet or swapped, Flavoured toothpaste stopped, Supplements stopped or checked with the vet, Other pets fed separately, bowls lifted straight after | Verified, 2026-09-11 |
| UK charity trial length, 6–12 weeks | 6, 12 | Verified, 2026-09-11 |
| "Ring the vet" thresholds (the tool's own) | itchScore 8; itchDays 3; earDays 2; foldDays 2; diarrhoeaDays 3; flareRise 2 | Our own threshold, labelled |
Before you start
Do it with a vet. The choice of diet is the part that goes wrong quietly: a "novel" protein the dog has met in a treat, or a food that shares an ingredient with the old one, wastes eight weeks and proves nothing. Fleas have to be ruled out first and kept out throughout; the guideline says year-round flea control, no exception. An ear or skin infection needs treating on its own, because infections cause flares whatever the diet is doing. The allergy page has the longer version; the feeding guide has the part about running it strictly or not at all; the best dog food page has why the trial diet is the hydrolysed one and not a shop bag marked hypoallergenic.
Common questions
How long does an elimination diet take?
Eight weeks, and not less. In the published review of trials, more than 80% of food-allergic dogs were better by week 5, and more than 90% by week 8; the authors' conclusion is that a trial should last at least eight weeks. UK charities say six to twelve. A trial that stops at four weeks because "nothing happened" has not tested anything.
What can he eat during the trial?
The diet, and water. Nothing else at all: no treats, no chews or dental sticks, no table food, no flavoured medicines or toothpaste, no supplements, and no finishing the other dog's bowl. The reason trials fail is nearly always that something else was fed, often by someone who did not know. The log has the list as a checklist and a daily "anything else eaten?" question because of that.
What is the itch scale?
The owner-assessed pruritus scale developed for dogs by Hill and colleagues and validated by Rybníček and colleagues in Veterinary Dermatology. Zero is a normal dog, ten is a dog that itches constantly and has to be physically stopped, and the validation put the normal range at 0 to 1.9. It is the same scale on the diet-trial diaries UK dermatology labs hand out. Our wording is adapted from a published reproduction, because the original paper is behind a paywall.
How likely is it that food is the cause?
Less likely than the internet suggests, and worth ruling out anyway. Across studies, food allergy accounted for 1% to 2% of all dogs seen by a vet and 9% to 40% of itchy dogs. The commonest culprits in dogs are beef, dairy, chicken, wheat, which is why "grain-free" so often changes nothing.
What is the challenge?
The second half of the test. If the dog is better after eight weeks, the vet will usually ask you to feed the old food again. A flare within 14 days is what confirms a food allergy; the published work found more than 90% of food-allergic dogs flare inside that window. The log has a challenge mode that counts the days and marks the flare. Start it only when the vet says so.
Why are ears and folds on the daily card?
Because in a French Bulldog they are where allergy shows first and worst. A recurring ear infection is often the first sign, before the skin; a fold that keeps getting sore despite cleaning is usually an allergy presenting where the skin barrier is weakest. A diary that only tracks scratching misses both.
Where does the diary go?
Nowhere. It is saved in your browser on this device and never sent to us or anyone else. That also means clearing your browser's site data deletes it, so use "Save a backup" now and then; the backup is a small file you can restore on another device or after a clear-out.
Related reading
A diary built from published veterinary guidelines, not veterinary advice. It records what you saw and puts the published figures beside it; your vet interprets both. If your dog is in distress, ring your practice.