The Truth About Dry Food: What 20 Years in Vet Medicine Taught Me

I'm going to say something that might be controversial: most cats eat too much dry food and not nearly enough moisture. And it is quietly shortening their lives.

I want to be careful here. I'm not here to make anyone feel guilty. Most cat owners feed dry food because that's what they were told to do, because it's convenient, because the bag has a picture of a healthy cat on it. The marketing is excellent. The reality is more complicated.

Cats Are Obligate Carnivores — And That Changes Everything

This is the foundational fact: cats are obligate carnivores. Their bodies are designed, at a cellular level, to derive nutrition from animal protein and fat. They have no biological requirement for carbohydrates. None.

In the wild, a cat's diet is roughly 70% moisture, 20% protein, 8% fat, and less than 2% carbohydrates. That moisture comes from the prey itself.

Now look at the average dry cat food. Moisture content: 8–10%. Carbohydrate content: 25–50%. This is not what a cat's body was built to process. And over years of eating this way, the consequences accumulate.

The Kidney Connection

Chronic kidney disease is the leading cause of death in domestic cats. It affects an estimated 30–40% of cats over age ten. I have watched more cats than I can count decline from kidney disease.

Is dry food the only cause? No. But chronic dehydration — the kind that comes from a lifetime of eating food with 8% moisture instead of 70% — is a significant contributing factor. The kidneys work harder than they should, for longer than they should, and eventually they wear out.

The Carbohydrate Problem

Dry food requires a binding agent to hold its shape. That binding agent is almost always a starch — corn, wheat, rice, potato, pea. Cats have no digestive enzyme specifically designed to process carbohydrates efficiently. Their bodies convert excess carbs to fat and glucose in ways that, over time, contribute to obesity and diabetes.

Feline diabetes has increased dramatically over the past few decades. The timeline correlates almost exactly with the rise of dry food as the primary diet for domestic cats. I'm not saying that's the only factor. But it's not a coincidence either.

So What Do I Actually Feed?

I feed Kit — and recommend for the cats I care for — a diet that is primarily wet food, ideally grain-free, with high-quality animal protein as the first ingredient. Not "chicken meal." Not "poultry by-product." Actual chicken. Actual fish. Actual meat.

I like Tiki Cat, Weruva, and Ziwi Peak for wet food. For treats, single-ingredient freeze-dried proteins — Vital Essentials is my go-to. For cats who need the dental benefits of dry food, a small amount of high-quality, low-carb kibble as a supplement, not a staple.

What About Dental Health?

The most common argument for dry food is that it cleans teeth. I want to address this directly: the evidence for this claim is weak. Most cats don't chew their kibble long enough or at the right angle for it to have any meaningful abrasive effect on tartar.

Dental disease affects an estimated 70% of cats over three years old — and it happens in cats who eat dry food too. If dental health is your concern, the most effective interventions are: regular professional cleanings, dental treats specifically designed for plaque reduction, dental gels, and — if your cat will tolerate it — tooth brushing.