Wet vs Dry Dog Food: How to Compare Labels Fairly

PetFoodFix content is educational and does not diagnose or treat illness. If your dog is unwell, has a diagnosed condition, is under 12 months old, is pregnant or lactating, is on a prescription diet or chronic medication, or has vomiting, diarrhoea, blood in stool, collapse, severe pain, breathing difficulty, refusal to eat for more than 24 hours, marked weight loss, severe itching, or suspected poisoning, contact your vet before changing food.

The comparison trap

A common mistake when comparing dog foods is looking at the protein, fat, or fibre percentages on a wet food and a dry food side by side. The numbers look very different — but the comparison is misleading.

A dry food showing 26% protein and a wet food showing 9% protein are not as far apart as they seem. The reason is moisture.

Why moisture changes everything

Dry dog food (kibble) typically contains 8–10% moisture. Wet dog food (tins, pouches, trays) typically contains 75–82% moisture. That water dilutes every other nutrient percentage on the label.

When you read "9% crude protein" on a wet food pouch, most of the remaining weight is water. If you remove the water, the protein concentration is much higher.

Dry matter comparison

To compare wet and dry foods fairly, convert both to a "dry matter basis":

Step 1: Find the moisture percentage (declared on wet food; estimate 8% for dry food if not stated)

Step 2: Subtract moisture from 100 to get the dry matter percentage

Step 3: Divide each nutrient by the dry matter fraction

Example — Wet food:

Crude protein: 9%, Moisture: 80%

Dry matter = 100 − 80 = 20%

Protein on dry matter basis = 9 ÷ 0.20 = 45%

Example — Dry food:

Crude protein: 26%, Moisture: 8%

Dry matter = 100 − 8 = 92%

Protein on dry matter basis = 26 ÷ 0.92 = 28.3%

In this example, the wet food actually delivers significantly more protein per unit of dry matter than the dry food.

Practical differences

Beyond the numbers, wet and dry foods have practical differences worth considering:

Dry food (kibble)

Longer shelf life once opened (store in a sealed container)
More calorie-dense per gram, so smaller portions
Generally cheaper per day of feeding
Can support dental abrasion (though this is debated)
Easier to measure and store

Wet food (tins, pouches, trays)

Higher moisture supports hydration, useful for dogs that drink little
Often more palatable for fussy eaters
Shorter shelf life once opened (refrigerate and use within 48 hours)
Higher cost per day due to water weight
Heavier to carry and more packaging waste

Mixed feeding

Many owners feed a combination — a base of dry food with a wet food topper. This can work well, but check that:

The dry food is labelled "complete" (not just the wet addition)
You adjust the dry food portion downward to account for the extra calories
The wet food is suitable as a complementary addition

Cost comparison

Comparing price per kilogram between wet and dry food is misleading because of the water content difference. A more useful comparison is cost per day based on the feeding guide for your dog's weight.

For example:

A 12kg bag of dry food at £40 lasting 60 days = ~£0.67 per day

A box of 12 wet food pouches at £8 lasting 4 days = ~£2.00 per day

This does not mean dry food is automatically better value — you are comparing the actual cost of feeding your dog, not the price of water.

What to check on the label

Whether you choose wet, dry, or a mix, the same label fundamentals apply:

Complete or complementary? — Is this a full meal or an addition?
Named protein sources? — Can you see which animal is used and at what percentage?
Analytical constituents — Compare on a dry matter basis if switching formats
Feeding guide — Use the recommended portion for your dog's weight as a starting point

How PetFoodFix compares foods

When you search the database, PetFoodFix analyses both wet and dry foods against the same quality framework. The scoring accounts for moisture differences, so a high-quality wet food and a high-quality dry food can both score well.

The report also includes a daily portion estimate and calorie calculation tailored to your dog, regardless of food format.

See how it works: view a sample report.

Want to compare your dog's food against the database? Start your analysis — £14.90, one-off.