What to record during a food trial (and what your vet actually reads)
Eight weeks is longer than memory is reliable, and the improvement you are watching for is gradual by nature.
Five things, once a day
The log that gets kept is the one that takes under a minute. Elaborate spreadsheets get abandoned in week two, and an abandoned log is worse than a simple one because it creates a gap exactly where the comparison matters.
- 1
Everything consumed
Meals, treats, chews, medications, supplements, anything scavenged. The exceptions are what break trials, so record them honestly — a logged slip is recoverable, an unlogged one invalidates the week.
- 2
Itch score out of ten
One number, same time each day. Absolute accuracy matters far less than consistency, because you are reading the trend, not the value.
- 3
Where they scratched
Paws, ears, face, belly, base of tail. Shifts in distribution are informative even when overall intensity is unchanged.
- 4
Ears and digestion
Head shaking, smell, discharge; stool consistency and frequency. These often improve before the skin visibly does.
- 5
Anything unusual
New environment, a stay in kennels, a bath with a different shampoo, a course of medication. Context explains outliers you would otherwise misread as diet effects.
Take photographs weekly
Skin change is visual and slow, and it is the thing owners are worst at judging by memory. A weekly photograph of the same two or three affected areas, in the same light, is the single most useful record you can produce — it turns "I think maybe slightly better?" into something a vet can assess in seconds.
Same spot, same lighting, same day of the week. Consistency beats image quality.
Bring it to the appointment
A vet reading eight weeks of daily scores and a photo series can form a judgement almost immediately. The same information delivered verbally takes ten minutes and arrives distorted by recency — you will describe the last three days, because those are the ones you remember.
It also protects you against the most common bad outcome: being told the trial was inconclusive because compliance could not be verified. A complete log is evidence that the trial was run properly, which makes the negative result useful rather than discardable.
Free, no account
The 8-week trial tracker, free
A printable daily log built to hand straight to your vet: meals and medications, itch score, ears and digestion, and the weekly photo prompts that make gradual improvement visible.
The tracker, and occasionally a new guide. Nothing else, and you can leave any time. How we handle your data .
- Daily meals, treats and flavoured medications
- Itch score, ears, digestion, scratch locations
- Weekly photo prompts, same spot and light
- A rechallenge section for weeks 8–9
Common questions
How detailed does the food log need to be?
Less detailed than most people assume. Everything consumed, one itch score, where they scratched, ears and digestion, plus anything unusual. A log you keep for eight weeks beats a thorough one you abandon in week two.
What if I slip up and give the wrong treat?
Record it and carry on. A single logged slip is interpretable — your vet can account for it. An unlogged slip is what makes the whole trial unreliable, because the resulting flare looks like the diet failing.
Read next
The 8-week elimination diet trial, step by step
It is the only reliable way to diagnose a food allergy in a dog or cat. It is also the protocol owners most often abandon halfway. Here is what the eight weeks actually involve.
Why is my dog itching? Working through the causes in order
Itching is the single most common reason dogs are taken to the vet. It is also the symptom most often treated in the wrong order, which is why it drags on for months.
Why is my cat itching, scratching, or overgrooming?
Cats rarely scratch in front of you. They groom it away in private, which is why feline itch is usually spotted weeks late, and often mistaken for fussy grooming.