depends...could be dandruff...my brother had a problem with a cat leaving tiny white pellets everywhere, it turned out to be worms!
Does it look grainy like sand? It's flea larvae...RUN to the vets. Dried saliva is what causes allergies in people, not dead skin [dandruff]. And isolate the affected blanket or cushion as fleas will burrow into and ruin it when they hatch.
You can give a cat a flea killing shampoo bath, BUT...make sure to put a towel on porcelain so they feel good footing and don't freak out and... wear gloves against scratching. Dry them off well afterward to keep your bond with them and show you weren't punishing them.
Pet dander....that much of it, could be a sign of an underlying illness....or, at the least, an allergy....She needs to be checked by the vet.
If it's dandruff it will look like dandruff (the same as humans get). If it is tiny little white grains, about the size of a pin-head, then it is flea eggs. If it is little white or off-white pellets like sesame seeds, then it is tape worms.
Either way, take her to the vet to get a treatment.
Is it a white cat? It could be hair. Or kittens! Does the 'white stuff' look like smaller versions of the larger cat? It could be kittens.
...lol Sorry, I couldn't help myself.
Yes....straight to the vet, she has a serious problem
Dandruff! It happens when they lick themselves. That is why alot more people are allergic to cats and not dogs. Dogs do not get it as bad. Giving it frequent baths will work. And bathe him in something that hydrates the skin. Like baby shampoo. That is what I use on my dogs and kitten and it keeps there skin from flaking which is what dandruff is basically.