3 Cat Diet Myths That Need to Go

Estimated reading time: 4–5 minutes

Cat owners are some of the most well-meaning pet parents around — which is exactly why cat diet myths spread so easily. One person says dry food cleans teeth. Another says cats naturally know when to stop eating. Someone else insists tuna is basically a cat superfood.

The problem? Cats are not just “small dogs with attitude.” Their nutritional needs are very specific, and some of the most common feeding beliefs can quietly create health problems over time.

If you live in Singapore, this gets even more relevant. Indoor living, compact homes, hot weather, and easy access to treats, toppers, and human food can all shape how we feed our cats.

Here are three of the most common misconceptions about cat diet — and what the evidence actually says.

Misconception #1: “Dry Food Is Fine as the Main Diet Because Cats Will Just Drink More Water”

This is probably one of the most persistent cat feeding myths out there.

Yes, cats can drink water. But the bigger question is whether they naturally drink enough to make up for a dry-food-heavy diet — and in many cases, they don’t.

Cats evolved from desert-adapted ancestors and have a naturally low thirst drive. Research published in the British Journal of Nutrition and other feline nutrition literature has shown that cats eating wet food generally have higher total water intake than cats eating dry food, even when dry-fed cats have free access to water. In other words, many cats do not fully compensate by drinking more.

Why does this matter? Because low water intake is closely linked to more concentrated urine, which can increase the risk of urinary issues. Feline lower urinary tract disease (FLUTD), including idiopathic cystitis and urinary crystal formation, is a major clinical issue in cats. Increased dietary moisture is commonly recommended in veterinary medicine, especially for cats prone to urinary problems.

This is especially relevant in Singapore’s warm climate, where cats may lose more water through normal daily activity and where indoor air-conditioning can also affect hydration patterns. For cats living mostly indoors — which is common here — owners may not notice subtle dehydration until urinary issues show up.

What this means in practice:

• Dry food is not automatically “bad,” but assuming water bowls alone will fully compensate is risky.

• If your cat is on mainly kibble, consider adding wet food regularly to increase moisture intake.

• Water fountains can help, but they are not a guaranteed fix for low moisture intake from diet.

• Cats with a history of urinary issues should have their diet reviewed with a vet, not guessed based on internet advice.

Misconception #2: “Cats Can Eat Fish or Tuna All the Time — They Love It, So It Must Be Good for Them”

Cats do love fish. That part is true. But “my cat loves it” is not the same as “this should be the main diet.”

Feeding tuna or fish-heavy meals too often can create several problems.

First, many fish-based foods — especially human-grade canned tuna not formulated for cats — are not nutritionally complete. Cats are obligate carnivores, but that doesn’t mean any meat or fish on its own is balanced enough. They require specific nutrients such as taurine, arachidonic acid, vitamin A, and certain B vitamins, all in the right proportions. A diet made up largely of plain tuna or unbalanced fish meals can lead to deficiencies over time.

Second, excessive fish intake has been associated with thiamine deficiency in cats when diets are not properly balanced. Thiamine deficiency can cause serious neurological signs, including weakness, loss of appetite, seizures, and abnormal posture. Veterinary nutrition literature has long recognised this risk in cats fed unbalanced fish-heavy diets.

Third, fish can contribute to food selectivity. Cats are notorious for imprinting on strong flavours and textures. If they get used to tuna frequently, some begin rejecting more balanced diets altogether. Anyone who has had a cat suddenly decide that only one specific topper is acceptable knows exactly how quickly this can spiral.

In Singapore, this myth gets reinforced because fish is such a normal part of the household diet. It’s easy to assume that a little steamed fish, canned tuna, or fish flakes from the dinner table is a wholesome treat. But once it becomes frequent, the balance starts to shift.

What this means in practice:

• Fish should be treated as a protein option, not the default foundation of every meal unless the food is commercially formulated to be complete and balanced.

• Avoid feeding plain canned tuna for humans as a regular meal replacement.

• If you use fish as a treat or topper, keep it occasional and small.

• If your cat starts refusing regular food unless fish is added, that is not a cute preference — it is a feeding habit worth correcting early.

Misconception #3: “If My Cat Is Hungry, It Will Stop Eating When It’s Full”

This sounds reasonable. It also happens to be one of the reasons so many indoor cats become overweight.

Unlike the popular image of cats as naturally self-regulating grazers, many cats will absolutely overeat when food is highly palatable, freely available, or tied to boredom and routine. Research published in the Journal of Veterinary Internal Medicine and broader feline obesity literature has consistently shown that obesity is one of the most common nutritional disorders in pet cats, especially indoor cats.

Neutered cats are at even higher risk. Studies have shown that after neutering, cats often experience changes in energy needs and appetite regulation, which can lead to weight gain if food intake is not adjusted. The problem is that many owners continue feeding the same amount — or even more, because the cat seems “always hungry.”

And in Singapore, this is a very familiar setup:

• cats living indoors full-time,

• limited space for high activity,

• treats used for bonding,

• and owners topping up bowls because an empty bowl feels like neglect.

The result? A cat that is quietly gaining weight while still acting hungry every time someone walks into the kitchen.

Feline obesity is not just a cosmetic issue. It is linked to:

• diabetes mellitus

• osteoarthritis

• reduced grooming ability

• higher anaesthetic risk

• and poorer overall quality of life

There is also a serious cat-specific concern: if overweight cats stop eating suddenly, they are at risk of hepatic lipidosis, a potentially life-threatening liver condition.

What this means in practice:

• Don’t judge feeding amounts by how dramatic your cat acts. Many cats are excellent manipulators.

• Measure portions properly instead of free-pouring kibble.

• Reassess calorie needs after neutering, and again as your cat ages.

• Use puzzle feeders or split meals into smaller portions through the day if your cat constantly begs.

• In small Singapore apartments, enrichment matters just as much as portion control. Some cats are not hungry — they are bored.

Final Thoughts

Cat diet myths tend to sound harmless because they’re often built around things cats seem to enjoy — dry food, tuna, constant snacking. But enjoyment and nutritional suitability are not the same thing.

If you remember just three things, let it be these:

1. Cats often do not drink enough to compensate for a dry-only diet

2. Fish is not automatically a perfect everyday food

3. Many cats will overeat if given the chance

For cat owners in Singapore, these points matter even more because indoor living, warmer weather, and common feeding habits can quietly push cats toward dehydration, fussiness, or weight gain.

The best diet for your cat is not the trendiest one — it’s the one that is balanced, appropriate for their health needs, and sustainable for your household.

And if your cat has urinary issues, weight problems, or has become extremely picky, that’s the point where your vet should be part of the conversation.

Comment below or share in our instagram post what other cat tips you have for your cats!