The wet-versus-dry argument is one of the oldest in cat ownership and most of the loud opinions are wrong in one direction or another. Both formats can be nutritionally complete. They differ in moisture, texture, calorie density, shelf life, and cost. The right answer for your cat usually involves both.
What's actually in each
Wet food is around 70–80% water. The protein content per calorie is typically higher than dry. It comes in cans or pouches, has to be refrigerated after opening, and spoils within a day or two.
Dry food is around 6–10% water. It's cooked at high heat into kibble, which means more carbohydrates are needed to bind it (typically 30–40% by dry matter). It keeps for months in a sealed bag and can sit out all day without spoiling.
Both formats can carry an AAFCO or FEDIAF "complete and balanced" statement. That's the floor. Above the floor, ingredient quality varies enormously within each format.
Why wet food wins on hydration
Cats have a weak thirst drive. They evolved to get most of their water from prey. A cat eating only dry food often runs at the edge of mild chronic dehydration, which contributes to urinary tract disease and kidney problems over time.
A cat on wet food gets roughly 60–70 ml of water per can. A cat on dry food has to drink that same amount voluntarily, which most cats won't. This is the single strongest argument for wet food, especially for males (prone to urinary blockages) and seniors (declining kidney function). See cat water intake for the full picture.
Why dry food wins on convenience and cost
- Cheaper per calorie, often by 3–5x.
- Doesn't spoil if left out, which suits puzzle feeders and slow eaters.
- Easier to store in bulk.
- Travel-friendly. You can throw a bag in a car without a cooler.
For a multi-cat household on a budget, dry is the realistic baseline. For a single cat with a small food budget, wet is more affordable than people assume.
The dental myth
You'll see claims that dry food cleans teeth. It mostly doesn't. Most kibble shatters at first bite rather than scraping the tooth surface. The exception is kibble specifically designed and tested for dental health (look for the VOHC seal), which has larger, fibrous pieces that make the cat actually chew.
What does protect teeth: brushing, regular dental cleanings at the vet, and dental treats with the VOHC seal. Wet versus dry isn't the lever people think it is. I had a cat on premium dry kibble his whole life. Still had four extractions at age nine.
When to mix, and how
Most cats do best on a mixed feeding plan:
- Wet meal in the morning and evening, portioned by the can label.
- A small measured amount of dry food as a midday top-up or in a puzzle feeder.
You get the hydration of wet food, the convenience of dry, and the enrichment of foraging behavior. It also means a sick cat who goes off one format will often still eat the other, which buys you time.
Mix the brands too if you can. Cats who eat only one flavor for years become impossible to switch when they develop a condition that requires a prescription diet. Rotate proteins (chicken, turkey, fish, rabbit) and formats (paté, chunks in gravy, kibble) from kittenhood when possible.
Cost in real numbers
For an average 4 kg adult cat needing roughly 200 kcal/day:
- All dry: $15–40/month depending on brand.
- All wet: $50–120/month.
- Mixed (wet meals, dry top-up): $35–80/month.
Premium and prescription diets sit at the top of each range. Store brands at the bottom. The middle of the market is fine for most cats.
The simple rule
If you're only going to feed one format, feed wet. If convenience or cost rules out all-wet, do a mix. Wet at meals, dry as a top-up. Pure dry is workable but ask your vet to monitor kidney values once a year from middle age onward, and add a water fountain.
The worst diet is the one you stop feeding because it's a hassle. Whatever you pick, make it sustainable.