Why can the same kibble score differently on different rating sites?

Quick answer

Why can the same kibble: Because each site applies its own scale: the criteria chosen, the weightings, the thresholds and the treatment of additives all differ (WSAVA, 2021). The same recipe can earn an excellent grade on one site and a mediocre one on another, without the product changing at all.

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General documentary information. For an individual animal, a veterinarian's advice takes precedence over any online content.

Detail

Heterogeneous scales

The spread in grades comes from each site's methodological choices: the weight given to the rank of the meat, whether grains are penalised, how additives are treated, how carbohydrate is estimated (WSAVA, 2021). Two scales can reward opposite things. The illustration that lays it bare: the same food can be rated excellent by a site that penalises grains and average by one that rewards digestibility, working from the identical label.

What this divergence reveals

The variability of grades shows that none is an objective measure of quality, but the reflection of a methodological stance (Tufts Petfoodology, 2023). The FEDIAF and AAFCO nutrient profiles, by contrast, are stable references for adequacy (AAFCO, 2024). Faced with contradictory grades, it is better to return to the verifiable criteria: adequacy, the maker's expertise, quality control, which do not shift with the scoring fashion.

At a glance
Source of divergenceEffect on the grade
Criteria chosenOpposite grades possible
Weightings and thresholdsUp or down
Treatment of additivesVariable bonus or penalty
The Petipedia angle

Petipedia explains why grades diverge and points back to stable references for adequacy, without setting up its own ranking.

Sources

WSAVA, Global Nutrition Guidelines (2021); Tufts Petfoodology (2023); AAFCO, Understanding Pet Food (2024).