Cat Nutrition

The phrase gets used loosely, but it has specific consequences. Cats cannot make taurine in adequate amounts and must get it from animal tissue — a deficiency causes heart disease and blindness. They convert beta-carotene to vitamin A poorly and need preformed vitamin A from animal sources. They run a higher baseline protein requirement than dogs and will break down their own muscle to meet it if the diet falls short.

The practical upshot is that a cat cannot be fed like a small dog, and vegetarian diets for cats are a genuinely different proposition from vegetarian diets for dogs. It also explains why "complete and balanced" on a cat food label is doing more work than the same phrase on a dog food.

Cats descend from desert animals and evolved to extract most of their water from prey, which was roughly seventy percent moisture. Their thirst drive is correspondingly weak — a cat on dry food alone frequently does not drink enough to compensate, and runs mildly dehydrated as a baseline state.

That has downstream effects on urinary and kidney health, and it is the strongest single argument for including wet food. If dry food suits your household better, the counter-measures are worth taking seriously: multiple water stations away from the food bowl, wide shallow bowls that do not touch the whiskers, and for many cats a running fountain, which they will use far more readily than standing water.

Kittens produce lactase to digest their mother's milk and mostly stop after weaning, which leaves the average adult cat lactose intolerant. The milk is not toxic, but the undigested lactose ferments in the gut and produces exactly the results that implies. The cat will usually drink it enthusiastically, which is why the myth survives — enthusiasm is not tolerance.

The full picture on dairy has some nuance, and cat-specific lactose-free milks do exist. They are still calories with little nutritional purpose, though, and a treat that displaces balanced food in a small animal costs more than it looks like it does.