How to Read a Pet Food Label
Most of what makes a pet food label hard to read is not the chemistry. It is that the guarantee panel states legal bounds rather than measurements, the ingredient list is ordered by weight taken before the water comes out, and the fields you most want — carbohydrate, ash, calcium, who actually made the food — are optional. These pages explain each convention once, alongside the number for how often labels actually support it.
| Field | Required? | Disclosed on |
|---|---|---|
| Protein, fat, fibre, moisture | Yes | Effectively all |
| AAFCO statement | Yes | 1,373 readable (58.3%) |
| Calorie content (kcal/kg) | Yes | 1,839 (78.1%) |
| Calories per cup | No | 934 (39.7%) |
| Ash | No | 375 (15.9%) |
| Calcium | No | 604 (25.7%) |
| Magnesium (cat foods) | No | 118 of 1,242 (9.5%) |
| Who manufactured it | No | 248 (10.5%) |
| Carbohydrate | No | Never printed — it is estimated by subtraction |
The concepts
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Dry-matter basis
Two foods can print 10% and 30% protein and carry almost the same protein. Dry-matter basis removes the water so the numbers can be compared. Computed on 2,019 of 2,354 verified labels.
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Estimated carbohydrate
Carbohydrate is never printed on a pet food label. It is estimated by subtraction — and on 1,632 of our 2,000 estimates that subtraction rests on an assumed ash value, because only 15.9% of labels publish ash.
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AAFCO statement
Only 235 of 1,373 verified AAFCO statements (17%) were substantiated by an actual feeding trial. The rest are formulated to meet a profile on paper.
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Calorie content
Calorie density is what turns a price per bag into a price per meal. It is on 78.1% of the labels we have verified as kcal/kg — but only 39.7% state kcal per cup, which is the one feeding guides actually need.
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Legume load
The FDA's grain-free/DCM inquiry centres on how much legume a food contains, not whether it contains any. Legume load counts them in the first ten ingredients — 443 of 2,186 scored foods carry two or more.
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Ingredient order & splitting
Ingredients are listed by pre-cooking weight, which means fresh meat is weighed with its water still in. Splitting one ingredient into several entries moves each one down the list. Both are legal and both change what a list appears to say.
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Calcium & phosphorus
Excess calcium during growth is a documented skeletal risk for large-breed puppies. Calcium is disclosed on only 25.7% of the labels we have verified, and a calcium-to-phosphorus ratio is computable on 24.3%.
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Guaranteed analysis
A guaranteed analysis states minimums and maximums, not actual values. Protein and fat are floors, fibre and moisture are ceilings, and the real figure can sit some distance from either.
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Named vs generic protein
A named protein identifies its species; a generic one does not. Separately, only 10.5% of labels disclose whether the brand made the food or had it made — 135 say "manufactured by", 113 say "distributed by".
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Label transparency
Across 2,354 verified labels, the median food discloses about 47% of the fields we look for. Ash appears on 15.9%, calcium on 25.7%, the manufacturer on 10.5%.
Why this matters for anything you read about pet food
Every comparison anyone publishes — ours included — is built on these same optional fields. A site that ranks foods on carbohydrate without saying carbohydrate is estimated, or on calcium without saying three quarters of labels omit it, is not being more thorough than one that shows the gaps. It is being less careful. That is the reasoning behind the checks we refuse to run.
Ready to apply it? What is actually in pet food counts every contested ingredient across the corpus, and the methodology documents how each field is extracted from a label.