Why can't cats eat dog food?

Dog food doesn't meet cats' obligate carnivore requirements. It lacks adequate taurine, arachidonic acid, and retinol (vitamin A in a form cats can use), among other nutrients. Feeding dog food to cats long-term can cause serious deficiencies -- taurine deficiency alone can lead to dilated cardiomyopathy (heart muscle disease) and blindness.

Do indoor cats need fewer calories than outdoor cats?

Generally yes -- indoor cats move less than outdoor or indoor-outdoor cats, which lowers their daily energy expenditure. Combined with the metabolic effect of spay/neuter (also very common in indoor cats), indoor cats often need meaningfully fewer calories per kilogram than general reference ranges might suggest.

Is a high-protein diet safe for all cats?

For healthy cats, a diet rich in high-quality animal protein matches their obligate carnivore metabolism well. For cats with certain medical conditions -- particularly some stages of chronic kidney disease -- protein levels may need to be managed, but this should be guided by a vet based on bloodwork, not assumed.

Why do some senior cats lose weight even when eating normally?

Digestive efficiency decreases in older cats, meaning they may absorb fewer nutrients and less energy from the same food. Conditions like hyperthyroidism (which increases metabolic rate) and chronic kidney disease also become more common with age and can cause weight loss. Any unexplained weight loss in a senior cat warrants a vet check.

Understanding Cat Metabolism | PetCalculator

Cats have a genuinely unusual metabolism shaped by millions of years as obligate carnivores. Here's what makes feline metabolic physiology distinct, how life stage and lifestyle affect it, and what common myths get wrong.