Can pet cats drink milk powder meant for humans? No, cow's milk causes kittens to have diarrhea, which can lead to death, and they cannot get the nutrients needed to survive.

Ordinary cow or goat milk is far from enough for kittens, although the lactose in it is not as big a problem as the lack of fat.

Cat milk is about 10% fat. Whole cow's milk only has 3.5%. Most milk powders are skimmed and contain no fat. This is no good for kittens.

Ideally, KMR (Kitten Milk Replacer) is the best choice, but if you cannot buy KMR, then buy 10% cream. If it comes from goats, that's better because their milk has smaller fat molecules, which are more like the fat in cat milk, but if all you can find is cow's milk, use that. If you can find cream heavier than 10%, then dilute whole milk down to 10%.

At least in their first six weeks, they need this high fat content to meet their growth needs because they grow too fast.

It is very true that you cannot safely give adult cats cow's milk because they actually lose the ability to digest lactose at a few months old, but before that, lactose is not a problem for them. All milk contains lactose, even cat milk, so they must be able to digest this lactose during nursing.